#426 – Edward Gibson: Human Language, Psycholinguistics, Syntax, Grammar & LLMs

Edward Gibson is a psycholinguistics professor at MIT and heads the MIT Language Lab. Please support this podcast by checking out our sponsors: – Yahoo Finance: https://yahoofinance.com – Listening: https://listening.com/lex and use code LEX to get one month free – Policygenius: https://policygenius.com/lex – Shopify: https://shopify.com/lex to get $1 per month trial – Eight Sleep: https://eightsleep.com/lex to get special savings Transcript: https://lexfridman.com/edward-gibson-transcript EPISODE LINKS: Edward’s X: https://x.com/LanguageMIT TedLab: https://tedlab.mit.edu/ Edward’s Google Scholar: https://scholar.google.com/citations?user=4FsWE64AAAAJ TedLab’s YouTube: https://youtube.com/@Tedlab-MIT PODCAST INFO: Podcast website: https://lexfridman.com/podcast Apple Podcasts: https://apple.co/2lwqZIr Spotify: https://spoti.fi/2nEwCF8 RSS: https://lexfridman.com/feed/podcast/ YouTube Full Episodes: https://youtube.com/lexfridman YouTube Clips: https://youtube.com/lexclips SUPPORT & CONNECT: – Check out the sponsors above, it’s the best way to support this podcast – Support on Patreon: https://www.patreon.com/lexfridman – Twitter: https://twitter.com/lexfridman – Instagram: https://www.instagram.com/lexfridman – LinkedIn: https://www.linkedin.com/in/lexfridman – Facebook: https://www.facebook.com/lexfridman – Medium: https://medium.com/@lexfridman OUTLINE: Here’s the timestamps for the episode. On some podcast players you should be able to click the timestamp to jump to that time. (00:00) – Introduction (10:53) – Human language (14:59) – Generalizations in language (20:46) – Dependency grammar (30:45) – Morphology (39:20) – Evolution of languages (42:40) – Noam Chomsky (1:26:46) – Thinking and language (1:40:16) – LLMs (1:53:14) – Center embedding (2:19:42) – Learning a new language (2:23:34) – Nature vs nurture (2:30:10) – Culture and language (2:44:38) – Universal language (2:49:01) – Language translation (2:52:16) – Animal communication

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Lex Fridman?

  The following is a conversation with Edward Gibson, or Ted, as everybody calls him. He is a psycholinguistics professor at MIT. He heads the MIT Language Lab that investigates why human languages look the way they do. The relationship between cultural language and how people represent, process, and learn language. Also, he should have a book titled Syntax: A Cognitive Approach, published by MIT Press coming out this fall. So we'll call for that.

• 0:32Lex Fridman?

  And now, a quick few second mention of each sponsor. Check them out in the description. It's the best way to support this podcast. We got Yahoo Finance for basically everything you've ever needed if you're an investor. Listening for listening to research papers. Policy Genius for insurance. Shopify for selling stuff online. And Aidsleep for naps. Choose wisely, my friends. Also, if you want to work with our amazing team or just get in touch with me, go to alexfreeman.com/contact. And now, onto the full ad reads. As always, no ads in the middle. I try to make this interesting, but if you must skip, friends, please still check out the sponsors. I enjoy their stuff. Maybe you will too.

• 1:13Lex Fridman?

  This episode is brought to you by Yahoo Finance, a new sponsor. And they got a new website that you should check out. It's a website that provides financial management, reports, information, and news for investors. Yahoo itself has been around forever. Yahoo Finance has been around forever. I don't know how long, but it must be over 20 years. It's survived so much. It evolved rapidly and quickly, adjusting, evolving, improving, all of that. The thing I use it for now is there's a portfolio that you can add your account to. Ever since I had zero money, I used, boy, I think it's called TDM Ameritrade. I still use that same thing, just getting a basic mutual fund.

• 1:58Lex Fridman?

  And I think TDM Ameritrade got bought by Charles Schwab or acquired or merged. I don't know. I don't know how these things work. All I know is that Yahoo Finance can integrate that and just show me everything I need to know about my quote unquote portfolio. I don't have anything interesting going on, but it is still good to kind of monitor it to stay in touch. Now, a lot of people I know have a lot more interesting stuff going on investment-wise. So, all of that could be easily integrated into Yahoo Finance and you can look at all that stuff, the charts, blah, blah, blah. It looks beautiful and sexy and just helps you be informed. Now, that's about your own portfolio, but then also for the entirety

• 2:42Lex Fridman?

  of the finance information for the entirety of the world. That's all there. The big news, the analysis of everything that's going on, everything like that. And I should also mention that I would like to do more and more financial episodes. I've done a couple of conversations with Ray Dalio. A lot of that is about finance, but some of that is about sort of geopolitics and the bigger context of finance. I just recently did a conversation with Bill Ackman, very much about finance. And I did a series of conversations on cryptocurrency. Lots of, lots of brilliant people, Michael Saylor, so on. Charles Hoskins and Vitalik, I mean, just lots of brilliant people in that space, thinking about the

• 3:23Lex Fridman?

  future of money, future of finance. Anyway, you can keep track of all of that with Yahoo Finance. For comprehensive financial news and analysis, go to yahoofinance.com. That's yahoofinance.com. This episode is also brought to you by Listening, an app that allows you to listen to academic papers. It's a thing I've always wished existed. And I always kind of suspected it's very difficult to pull off, but these guys pulled it off. Basically, it's any kind of formatted text brought to life through audio. Now, for me, the thing I care about most, and I think that's at the foundation of Listening, is academic papers. So, I love to read academic

• 4:06Lex Fridman?

  papers. And there's several levels of rigor in the actual reading process, but listening to them, especially after I skimmed it, or after I did a deep dive, listening to them is just such a beautiful experience. It solidifies the understanding. It brings to life all kinds of thoughts. And I'm doing this while I'm cooking, while I'm running, while I'm going to grab a coffee, all that kind of stuff. It does require an elevated level of focus, especially the kind of papers I listen to, which are computer science papers. But you can load in all kinds of stuff. You can do philosophy papers. You could do psychology papers like this very topic of linguistics. I've listened to a few papers on linguistics.

• 4:51Lex Fridman?

  I went back to Chomsky and listened to papers. It's great. Papers, books, PDFs, webpages, articles, all that kind of stuff, even email newsletters. And the voices they got are pretty sexy. It's great. It's pleasant to listen to. I think that's what's ultimately most important is it shouldn't feel like a chore to listen to it. Like, I really enjoy it. Normally, you'd get a two-week free trial, but listeners of this podcast get one month free. So go to listening.com/lex. That's listening.com/lex. This episode is brought to you by PolicyGenius, a marketplace for insurance, life, auto, home, disability, all kinds of insurance. There's really nice tools for comparison. I'm a big fan of nice tools for comparison.

• 5:36Lex Fridman?

  Like, I have to travel to harsh conditions soon, and I had to figure out how I need to update my equipment to make sure it's weatherproof, waterproof even. It's just resilient to harsh conditions. And it would be nice to have sort of comparisons. I have to resort to Reddit posts or forum posts, kind of debating different audio recorders and cabling and microphones and waterproof containers, all that kind of stuff. I would love to be able to do like a rigorous comparison of them. Of course, going to Amazon, you get the reviews, and those are actually really, really solid. So I think Amazon's been the giant gift to society in that way, that you kind of can

• 6:21Lex Fridman?

  lay out all the different options and get a lot of structured analysis of how good this thing is. So Amazon's been great at that. Now, what PolicyGenius did is did the Amazon thing, but for insurance. So the tools for comparison is really my favorite thing. It's just really easy to understand, the full marketplace of insurance. With PolicyGenius, you can find life insurance policies that start at just $292 per year for $1 million of coverage. Head to policygenius.com/lex or click the link in the description to get your free life insurance quotes and see how much you can save. That's policygenius.com/lex.

• 7:05Lex Fridman?

  This episode is also brought to you by Shopify, a platform designed for anyone to sell anywhere with a great looking online store. I'm not name dropping here, but I recently went on a hike with the CEO of Shopify, Toby. He's brilliant. I've been a fan of his for a long time, long before Shopify was a sponsor. I don't even know if he knows that Shopify sponsors this podcast. Now, just to clarify, it really doesn't matter. Nobody in this world can put pressure on me to have a sponsor or not to have a sponsor, or for a sponsor to put pressure on me what I can and can't say. I, when I wake up in the morning, feel completely free to say what I want to say

• 7:49Lex Fridman?

  and to think what I want to think. I've been very fortunate in that way in many dimensions of my life. And I also have always lived a frugal life and a life of discipline, which is where the freedom of speech and the freedom of thought truly comes from. So I don't need anybody. I don't need a boss. I don't need money. I'm free to exist in this world in the way I sees right. Now, on top of that, of course, I'm surrounded by incredible people, many of whom I disagree with and have arguments. So I'm influenced by those conversations and those arguments. And I'm always learning, always challenging myself, always humbling myself. I have kind of intellectual humility. I kind of suspect I'm kind of an idiot.

• 8:36Lex Fridman?

  I start my approach to the world of ideas from that place, assuming I'm an idiot and everybody has a lesson to teach me. Anyway, not sure why I got on off that tangent, but the hike was beautiful. Nature, friends, is beautiful. Anyway, I have a Shopify store, lexfridman.com/store. It's very minimal, which is how I like, I think, most things. If you want to set up a store, it's super easy. Takes a few minutes, even I figured out how to do it. Sign up for a $1 per month trial period at Shopify.com/lex. That's all lowercase. Go to Shopify.com/lex to take your business to the next level today.

• 9:18Lex Fridman?

  This episode is also brought to you by Asleep. And it's part of the three cover. The source of my escape. The door, when opened, allows me to travel away from the troubles of the world into this ethereal universe of calmness. A cold bed surface with a warm blanket. A perfect 20 minute nap. And it doesn't matter how dark the place my mind is in. A nap will pull me out and I see the beauty of the world again. Technologically speaking, Asleep is just really cool. You can control temperature with an app. It's become such an integral part of my life that I've begun to take it for granted.

• 10:03Lex Fridman?

  Typical human. So the app controls the temperature. I set it currently, I'm setting it to a negative five. Then it's just super nice, cool surface. It's something I really look forward to, especially when I'm traveling. I don't have one of those. It really makes me feel like home. Check it out and get special savings when you go to asleep.com/lex. This is the Lex Fridman Podcast. To support it, please check out our sponsors in the description. And now to your friends, here's Edward Gibson.

• 10:53Lex Fridman?

  When did you first become fascinated with human language?

• 10:57Speaker 01

  As a kid in school, when we had to structure sentences in English grammar, I found that process interesting. I found it confusing as to what it was I was told to do. I didn't, didn't understand what the theory was behind it, but I found it very interesting.

• 11:14Lex Fridman?

  So when you look at grammar, you're almost thinking about like a puzzle, like almost like a mathematical puzzle?

• 11:19Speaker 01

  Yeah, I think that's right. I didn't know I was going to work on this at all at that point. I was really just, I was kind of a math. Geek person, computer scientist. I really liked computer science. And then I found language as a neat puzzle to work on from an engineering perspective. Actually, that's what I, as a, I sort of accidentally, I decided after I finished my undergraduate degree, which was computer science and math and candidate in Queens University. I decided to go to grad school. It's like, that's what I always thought I would do. And I went to Cambridge where they had a master's in, a master's program in computational linguistics. And I hadn't taken a single language class before. All I'd taken was CS,

• 12:02Speaker 01

  computer science, math classes, pretty much mostly as an undergrad. And I just thought this was an interesting thing to do for a year because it was a single year program. And then I end up spending my whole life doing it.

• 12:15Lex Fridman?

  So fundamentally, your journey through life was one of a mathematician and a computer scientist. And then you kind of discovered the puzzle, the problem of language and approached it from that angle to try to understand it from that angle, almost like a mathematician or maybe even an engineer.

• 12:33Speaker 01

  As an engineer, I'd say, I mean, to be frank, I had taken an AI class, I guess it was 83 or 84, 85, somewhere 84 in there, a long time ago. And there was a natural language section in there and it didn't impress me. I thought there must be more interesting things we can do. It didn't seem very, it seemed just a bunch of hacks to me. It didn't seem like a real theory of things in any way. And so I just thought this was, this seemed like an interesting area where there wasn't enough good work.

• 13:03Lex Fridman?

  Did you ever come across like the, the philosophy angle of logic? So if you think about the eighties with AI, the expert systems where you try to kind of maybe sidestep the, the poetry of language and the, some of the syntax and the grammar and all that kind of stuff. Go to the underlying meaning that language is trying to communicate and try to somehow compress that in a computer representable way. Do you ever come across that in your studies?

• 13:30Speaker 01

  I mean, I probably did, but I wasn't as interested in it. I was, I was trying to do the easier problems first, the ones I could thought maybe were handleable, which is, seems like the syntax is easier, like, which is just the forms as opposed to the meaning, like you're talking, when you're starting to talk about the meaning, that's a very hard problem and it still is a really, really hard problem. But the forms is, is easier. And so I thought at least figuring out the forms of human language, which sounds really hard, but is actually maybe more tractable.

• 13:59Lex Fridman?

  So it's interesting. You think there is a big divide. There's a gap. There's a distance between form and meaning. Because that's a question you have discussed a lot with LLMs. Because they're damn good at form.

• 14:13Speaker 01

  Yeah, I think it's what they're good at is form. Exactly. And that's, that's why they're good, because they can do form. Meaning's hard.

• 14:19Lex Fridman?

  Do you think there's, oh, wow. And I mean, it's an open question, right? How close form and meaning are? We'll discuss it, but I, to me, studying form, maybe it's a romantic notion, gives you, form is like the shadow of the, the bigger meaning thing underlying language. As I, it, form is, language is how we communicate ideas. We communicate with each other using language. So in understanding the structure of that communication, I think you start to understand the structure of thought and the structure of meaning behind those thoughts and communication, to me. But to you, big gap.

• 14:58Speaker 01

  Yeah.

• 14:59Lex Fridman?

  What do you find most beautiful about human language? Maybe the form of human language, the expression of human language?

• 15:07Speaker 01

  What I find beautiful about human language is the, some of the generalizations that happen across the human language, just within and across a language. So let me give you an example of something which I find. Kind of remarkable that is if like a language, if it has a word order such that the verbs tend to come before their objects. And so that's like English does that. So we have the the first, the subject comes first in a, in a simple sentence. So I say, you know, the, the dog chased the cat or Mary kicked the ball. So the subject's first, the, and then after the subject, there's the verb. And then we have objects. All these things come after in English. So it's a, it's generally a verb. And most of the stuff that we want

• 15:50Speaker 01

  to say comes after the subject, it comes, it's the, it's the objects. There's a lot of things we want to say to come after. And, and, and there's a lot of languages like that. About 40% of the languages of the world are look like that. They're sub, subject, verb, object languages. And then these languages tend to have prepositions, these little markers on the nouns that, that connect nouns to other nouns or nouns to verbs. So I, when I saw a verb like, I saw a preposition like in or on or of or about, I say, I talk about something. The something is the object of that preposition that we have these little markers come also, just like verbs, they come before their, their nouns. Okay. And

• 16:32Speaker 01

  then, so now we look at other languages that like Japanese or, or Hindi or some, these are, these are so-called verb final languages. Those is about maybe a little more than 40%, maybe 45% of the world's languages or more, I mean, 50% of the world's languages are verb final. Those tend to be postpositions. Those markers, the same, we have, they have the same kinds of markers as we do in English, but they put them after. So, sorry, they put them first, the markers come first. So you say, instead of, you know, talk about a book, you say a book about, the opposite order there in Japanese or in Hindi, you do the opposite. And the, and the talk comes at the end. So the verb will come at the

• 17:16Speaker 01

  end as well. So instead of Mary kicked the ball, it's Mary ball kicked. And then if it's Mary kicked the ball to John, it's John to, the to, the little, the marker there, the preposition, it's a postposition in these languages. And so the interesting thing, fascinating thing to me is that within a language, This order aligns, it's harmonic. And so if it's one or the other, it's either verb initial or verb final, but then you'll have prepositions, prepositions, or postpositions. And so that, and that's across the languages that we can look at. We've got around 1,000 languages for, there's around 7,000 languages around on the, on the earth right now.

• 17:59Speaker 01

  But we have information about, say, word order on around 1,000 of those. Pretty decent amount of information. And for those 1,000 which we know about, about 95% fit that pattern. So they will have either verb, it's about, it's about half and half, half of verb initial, like English, and half of verb final, like, like Japanese.

• 18:21Lex Fridman?

  So just to clarify, verb initial is subject, verb, object?

• 18:25Speaker 01

  That's correct.

• 18:26Lex Fridman?

  Verb final is still subject, object, verb?

• 18:29Speaker 01

  That's correct. Yeah, the subject is generally first.

• 18:31Lex Fridman?

  That's so fascinating. I ate an apple, or I apple ate.

• 18:37Speaker 01

  Yes.

• 18:37Lex Fridman?

  Okay, and it's fascinating that there's a pretty even division in the world amongst those, 40, 45%.

• 18:43Speaker 01

  Yeah, it's pretty, it's pretty even. And, and those two are the most common by far, those two word orders. The subject tends to be first. There's so many interesting things, but these things are, the thing I find so fascinating is there are these generalizations within and across a language. And, and not only those are the, and there's actually a simple explanation, I think, for a lot of that. And that is, you're trying to like minimize dependencies between words. That's basically the story, I think, behind a lot of why word order looks the way it is, is you, we're always connecting. What is, what is the thing I'm telling you? I'm, I'm talking to you in sentences, you're talking to me in sentences. These are sequences of words which are connected. And the connections are dependencies between the words.

• 19:27Speaker 01

  And it turns out that what we, what we're trying to do In a language is actually minimize those dependency links. It's easier for me to say things if the words that are connecting for their meaning are close together. It's easier for you in understanding if that's also true. If they're far away, it's it's hard to produce produce that and it's hard for you to understand. And the languages of the world, within a language and across languages, you know, fit that generalization, which is, you know, so I, you know, it turns out that having verbs initial and then having prepositions ends up making dependencies shorter. And and having verbs final and having postpositions ends up making dependencies shorter than if you cross them. If you cross them, it ends up, you just end up, it's possible, you can do it.

• 20:12Lex Fridman?

  You mean within a language?

• 20:13Speaker 01

  Within a language, you can do it. It just ends up with longer dependencies than if you didn't. And so languages tend to go that way. They tend to minimize, they say, they call it harmonic. So it was observed a long time ago by, without the explanation, by a guy called Joseph Greenberg, who's a famous typologist from Stanford. He observes a lot of generalizations about how word order works, and these are some of the harmonic generalizations that he observed.

• 20:39Lex Fridman?

  Harmonic generalizations about word word order. There's so many things I want to ask you. Okay. Let me just sometimes basics. You mentioned dependencies a few times.

• 20:49Speaker 01

  Yeah.

• 20:50Lex Fridman?

  What do you mean by dependencies?

• 20:51Speaker 01

  Well, what I mean is, in in language, there's kind of three structures to, three components to the structure of language. One is the sounds. So cat is c, a, and t in English. I'm not talking about that part. I'm talking, then there's two meaning parts, and those are the words. And and you were talking about meaning earlier. So words have a form and they have a meaning associated with them. And so cat is a full form in English and it has a meaning associated with whatever a cat is. And then the combinations of words, that's what I'll call grammar or syntax. And that's like when I have a combination like the cat or two cats. Okay. So where I take two different words there and put them together and I get a compositional

• 21:34Speaker 01

  meaning from putting those two different words together. And and so that's the syntax. And in any sentence or utterance, whatever I'm talking to you, you're talking to me, we have a bunch of words and we're putting them together in a sequence. They, it turns out they are. Connected so that every word is connected to just one other word in that in that sentence. And so you end up with what's called technically a tree. It's a tree structure. So there where there's a root of that of that utterance of that sentence. And then there's a bunch of dependents, like branches from that root that go down to the words. The words are the leaves in this metaphor for a tree.

• 22:14Lex Fridman?

  So a tree is also sort of a mathematical construct.

• 22:16Speaker 01

  Yeah, yeah, it's a graph theoretical thing.

• 22:18Lex Fridman?

  Graph theory thing. So in this fascinating that you can break down a sentence into a tree. And then one, every word is hanging on to another, it's depending on it.

• 22:27Speaker 01

  That's right. And and everyone agrees on that. So all linguists will agree with that.

• 22:30Lex Fridman?

  Oh, so this is not a controversial.

• 22:32Speaker 01

  That is not controversial.

• 22:33Lex Fridman?

  There's nobody sitting here.

• 22:34Speaker 01

  I do not think so.

• 22:34Lex Fridman?

  Mad at you.

• 22:35Speaker 01

  I don't think so.

• 22:36Lex Fridman?

  OK, there's no linguist sitting there mad at this.

• 22:38Speaker 01

  No, I think in every language, I think everyone agrees that all sentences are trees at some level.

• 22:45Lex Fridman?

  Can I pause on that?

• 22:46Speaker 01

  Sure.

• 22:46Lex Fridman?

  Because it's to me, just as a layman, it's surprising.

• 22:51Speaker 01

  Yeah.

• 22:51Lex Fridman?

  That you can break down sentences in many mostly all languages.

• 22:56Speaker 01

  All languages, I think.

• 22:56Lex Fridman?

  Into a tree.

• 22:57Speaker 01

  I think so.

• 22:58Lex Fridman?

  That's.

• 22:59Speaker 01

  I I've never heard of anyone disagreeing with that.

• 23:01Lex Fridman?

  That's weird.

• 23:01Speaker 01

  The details of the trees are what people disagree about.

• 23:05Lex Fridman?

  Well, OK, so what's what's at the root of a tree? How do you construct? How hard is it? What is the process of constructing a tree from a sentence?

• 23:13Speaker 01

  Uh, well, this is where, you know, depending on what your there's theoretical notions. I'm going to say the simplest thing. Dependency grammar, it's like a bunch of people invented this. Tienier was the first French guy back in, I mean, the paper was published in 1959, but he was working on the 30s and stuff. So and and it goes back to, you know, philologist Pinini was doing this in ancient India. OK, and so, you know, doing something like this, the simplest thing we can think of is that there's just connections between the words to make the the utterance. And so it's just say I have like two dogs entered a room. OK, here's a sentence. And so we're connecting to and dogs together. That's like, there's some dependency between those words to make some bigger meaning.

• 23:58Speaker 01

  And then we're connecting dogs now to entered, right? And we connect a room somehow to entered. And so I'm going to connect ah to room and then room back to entered. These are, that's the tree is I, the root is entered. That's the, the thing is like an entering event. That's what we're saying here. And the, the subject, which is whatever that dog is, is two dogs it was. And, and the connection goes back to dogs, which goes back to them. Then that, that goes back to two. I'm just, that, that's my tree. It, it starts at entered, goes to dogs, down to two. And then the other side, after the verb, the object, it goes to room. And then that goes back to the, the determiner or article, whatever you want to call that word ah. So there's a bunch of categories of words here we're noticing. So there are verbs.

• 24:42Speaker 01

  Those are these things that typically mark, uh, they refer to events and states in the world. And they're nouns, which typically refer to people, places and things is what people say. But they can refer to other more, I think you've heard of events themselves as well. They're, they're, they're marked by, you know, how they, how they, you, what, what the category, the part of speech of a word is how it gets used in language. It's like, that's how you decide what the, what the category of a word is. Not, not by the meaning, but how it's, how it gets used.

• 25:11Lex Fridman?

  How it's used. What's usually the root? Is it going to be the verb that defines the event?

• 25:16Speaker 01

  Usually, usually, yes, yes.

• 25:18Lex Fridman?

  Okay.

• 25:18Speaker 01

  Yeah. I mean, if I don't say a verb, then there won't be a verb. And so it'll be something else.

• 25:22Lex Fridman?

  What if you're messing, are we talking about language that's like correct language? What if you're doing poetry and messing with stuff? Is it, then, then rules go out the window, right? Then it's.

• 25:31Speaker 01

  No.

• 25:32Lex Fridman?

  You're still.

• 25:32Speaker 01

  No, no, no, no. You're constrained by whatever language you're dealing with. Probably you have other constraints in poetry such that you're like, usually in poetry, there's multiple constraints that you want to, like you want to usually convey multiple meanings is the idea. And maybe you have like a rhythm or a rhyming structure as well. And depending, so, but you usually are constrained by your, the rules of your language for the most part. And so you don't. Violate those too much? You can violate them somewhat, but not too much. So it has to be recognizable as your language. Like in English, I can't say dogs two entered room A. I mean, I meant that, you know, two dogs entered a room. And I can't mess with the order of the articles, the articles and the nouns. You just can't do that.

• 26:17Speaker 01

  In some languages, you can, you can mess around with the order of words much more. I mean, you speak Russian. Russian has a much freer word order than English. And so, in fact, you can move around words in, you know, I told you that English has this subject, verb, object word order. So does Russian, but Russian is much freer than English. And so you can actually mess around with the word order. So probably Russian poetry is going to be quite different from English poetry because the word order is much less constrained.

• 26:44Lex Fridman?

  Yeah, there's a much more extensive culture of poetry throughout the history of the last hundred years in Russia. And I always wondered why that is. But it seems that there's more flexibility in the way the language is used. There's more, you're morphing the language easier by altering the words, altering the order of the words, messing with it.

• 27:05Speaker 01

  Well, you can just mess with different things in each language. And so in Russian, you have case markers, right? On the end, which are these endings on the nouns, which tell you how it connects, each noun connects to the verb, right? We don't have that in English. And so when I say Mary kissed John, I don't know who the agent or the patient is, except by the order of the words, right? In, in Russian, you actually have a marker on the end. If you're using a Russian name and each of those names, you'll also say, is it, you know, agent, it'll be the, you know, a nominative, which is marking the subject. And an accusative will mark the object. And you could put them in the reverse order. You could put accusative first. You could put subject, you could put the patient first and then the verb and then the, the, the subject.

• 27:50Speaker 01

  And that would be a perfectly good Russian sentence. And it would still mean Mary, I could say John kissed Mary, meaning Mary kissed John. As long as I use the case markers in the right way. You can't do that in English. And so.

• 28:01Lex Fridman?

  I love the terminology of agent and patient and.

• 28:04Speaker 01

  Yeah.

• 28:05Lex Fridman?

  And the other ones you used. Those are sort of linguistic terms, correct?

• 28:09Speaker 01

  Those are, those are for like, kind of meaning. Those are meaning and subject and object are generally used for position. So subject is just like the thing that comes before the verb. And the object is the one that comes after the verb. The agent is kind of like the thing doing it. That's kind of what that means, right? The, the subject is often the person doing the action, right? The thing, so, yeah.

• 28:28Lex Fridman?

  Okay, this is fascinating. So how hard is it to form a tree in general? Is there, um, is there a procedure to it? Like, if you look at different languages, is it supposed to be a very natural? Like, is it automatable or is there some human genius involved in?

• 28:41Speaker 01

  I think it's pretty automatable at this point. People can figure out the words are. They can figure out the morphemes, which are the, technically, morphemes are the, the minimal meaning units within a language. Okay. And so when you say eats or drinks, it actually has two morphemes in it in English. There's, there's the, there's the root, which is the verb. And then there's some ending on it, which tells you, you know, that's this third person, uh, third person singular.

• 29:03Lex Fridman?

  Can you say what morphemes are?

• 29:04Speaker 01

  Morphemes are just the minimal meaning units within a language. And then a word is just kind of the things we put spaces between in English. And they have a little bit more, they have the morphology as well. They have the endings, this inflexible morphology on the endings on the roots.

• 29:16Lex Fridman?

  They modify something about the word that adds additional meaning.

• 29:19Speaker 01

  They tell you, yeah, yeah, yeah. And so we have a little bit of that in English, very little. You have much more in Russian, for instance, and, and, but we have a little bit in English. And so we have a little on the, on the nouns. You can say it's either singular or plural. And, and you can say, uh, same thing for, um, for, for verbs, like simple past tense, for example. So like, you know, notice in English, we say drinks, uh, you know, he drinks, but everyone else is I drink, you drink, we drink. It's unmarked in a way. And then, but in the past tense, it's just drank there for everyone. There's no morphology at all for past tense. It's, if there is morphology, it's marking past tense, but it's kind of, it's an irregular now. So we don't even, you know, it drink to drank, you know? It's not even a regular word. So in most verbs, many verbs, there's an ed we kind of add. So walk to walked, we add that to say it's the past tense.

• 30:03Speaker 01

  That I just happen to choose an irregular because it's a high frequency word and the. High-frequency words tend to have irregulars in English for.

• 30:10Lex Fridman?

  What's an irregular?

• 30:10Speaker 01

  Irregular is just, there isn't a rule. So drink to drank is an irregular.

• 30:15Lex Fridman?

  Drink drank, okay.

• 30:17Speaker 01

  As opposed to walk, walked, talked, talked.

• 30:19Lex Fridman?

  And there's a lot of irregulars in English.

• 30:22Speaker 01

  There's a lot of irregulars in English. The frequent ones, the common words, tend to be irregular. There's many, many more low-frequency words. And those tend to be, those are regular ones.

• 30:32Lex Fridman?

  The evolution of the irregulars are fascinating. Because it's essentially slang that's sticky. Because you're breaking the rules and then everybody uses it and doesn't follow the rules. And they say screw it to the rules. It's fascinating. So you said morphemes, lots of questions. So morphology is what, the study of morphemes?

• 30:50Speaker 01

  Morphology is the connections between the morphemes onto the roots, the roots. So in English, we mostly have suffixes. We have endings on the words, not very much, but a little bit. And as opposed to prefixes, some words, depending on your language, can have, you know, mostly prefixes, mostly suffixes, or mostly, or both. And then even languages, several languages have things called infixes, where you have some kind of a general form for the root. And you put stuff in the middle, you change the vowels.

• 31:22Lex Fridman?

  That's fascinating. That is fascinating. So in general, there's what, two morphemes per word? Usually one or two or three?

• 31:31Speaker 01

  Well, in English, it's one or two. In English, it tends to be one or two, there can be more. You know, in other languages, you know, a language like Finnish, which has a very elaborate morphology, there may be 10 morphemes on the end of a root. Okay, and so there may be millions, there'd be millions of forms of a given word. Okay?

• 31:50Lex Fridman?

  Okay, I'll ask the same question over and over. But how does the, just sometimes to understand things like morphemes, it's nice to just ask the question, how do these kinds of things evolve? So you have a great book studying sort of the.

• 32:12Lex Fridman?

  How the cognitive processing, how language is for communication. So the mathematical notion of how effective a language is for communication, what role that plays in the evolution of language. But just high level, like, how do we, how does a language evolve with, where English is two morphemes or one or two morphemes per word, and then Finnish has infinity per word. So what, how does that, how does that happen? Is it just people?

• 32:38Speaker 01

  That's a really good question.

• 32:39Lex Fridman?

  Yeah.

• 32:40Speaker 01

  That's a very good question. It's like, why do languages have more morphology versus less morphology? And I don't think we know the answer to this. I know, I think there's just like a lot of good solutions to the problem of communication. So I, like, I believe, as you hinted, that language is an invented system by humans for communicating their ideas. And I think we, it comes down to we label the things we want to talk about. Those are the, the morphemes in words. Those are the things we want to talk about in the world, and we invent those things. And then we put them together in ways that are easy for us to convey, to process. But that, that's like a naive view, and I don't, I mean, I, I think it's probably right. Right? It's naive and probably right.

• 33:23Lex Fridman?

  Well, that's, I don't know if it's naive. I think it's simple.

• 33:26Speaker 01

  Simple, yeah.

• 33:26Lex Fridman?

  I think naive is, naive is an indication that's incorrect somehow. It's a trivial, too, too simple. I think it could very well be correct. But it's interesting how sticky, it feels like two people got together. It just feels like, once you figure out certain aspects of a language, that just becomes sticky and the tribe forms around that language. Maybe the language, maybe the tribe forms first, and then the language evolves. And then you just kind of agree and you stick to whatever that is.

• 33:56Speaker 01

  I mean, these are very interesting questions. We don't know really about how words, even words, get invented very much about, you know, we don't really, I mean, assuming they get invented, they, we don't really know how that process works and how these things evolve. What we have is kind of a current picture, a current picture of a few thousand languages, a few thousand instances. We don't have any pictures of really how these things are evolving, really. And, and then the evolution is massively, you know, confused by contact, right? So as soon as one language group, one group runs into another. We are smart. Humans are smart and they take on whatever is useful in the other

• 34:41Speaker 01

  group. And so any kind of contrast which you're talking about, which I find useful, I'm gonna, I'm gonna start using as well. So I worked a little bit in, in, in specific areas of words, in, in number words and in, in color words and color words that, so we have in English, we have around 11 words that everyone knows for colors and, and many more. If you happen to be interested in color for some reason or other, if you're a fashion designer or an artist or something, you may have many, many more words. But we can see millions. Like if you have normal color vision, normal trichromatic color vision, you can see millions of distinctions in color. So we don't have millions of words. You know,

• 35:23Speaker 01

  the most efficient, no, so the most, you know, detailed color vocabulary would have over a million terms to distinguish all the different colors that we can see. But of course, we don't have that. So it's somehow, it's been, it's kind of useful for English to have, have evolved in some way to, so there's 11 terms that people find useful to talk about, you know, black, white, red, blue, green, yellow, purple, gray, pink, and I probably missed something there. Anyway, there's, there's 11 that everyone knows. Yeah. And, and depending on your, and but you go to different cultures, especially the non-industrialized cultures, and there'll be many fewer. So some cultures will have

• 36:02Speaker 01

  only two, believe it or not, that, that Danai in Papua New Guinea have only two labels that the, that the group uses for color. And those are roughly black and white. They are very, very dark and very, very light, which are roughly black and white. And you might think, oh, they're dividing the whole color space into, you know, light and dark or something. And that's not really true. They mostly just only label the light, the black and the white things. They just don't talk about the colors for the other ones. And so, and, and then there's other groups. I worked with a group called the Chimani down in, in Bolivia in South America, and they have Three words that everyone knows, but there's a few others that are that that several people like that many people know. And so they have me, it's kind of depending on how you count between

• 36:47Speaker 01

  three and seven words that the group knows. Okay. And again, they're, they're black and white. Everyone knows those and red, red is, you know, like that tends to be the third word that everyone that that cultures bring in. Nice. If there's a word, it's always red, the third one. And then after that, it's kind of all bets are off about what they bring in. And so after that, they, they bring in a sort of a big, blue, green space. Gru, gru, they have one for that. And then they have, and then, you know, different people have different words that they'll use for other parts of the space. And so anyway, it's probably related to what they want to talk, what they, not what they, not what they see, because they see the same colors as we see. So it's not like they have, they don't, they have a, a weak,

• 37:31Speaker 01

  a, a low color palette and the things they're looking at. They're looking at a lot of beautiful scenery. Okay. A lot of different colored flowers and berries and things. And, you know, and so there's lots of things of very bright colors, but they just don't label a color in those cases. And the reason probably, we, we don't know this, but we think probably what's going on here is that what you do, why you label something is you need to talk to someone else about it. And why do I need to talk about a color? Well, if I have two things which are identical, and I want you to give me the one that's different, and, and the only way it varies is color, then I invent a word which tells you, you know, this is the one I want. So I want the red sweater off the rack, not the, not the green sweater, right? There's two.

• 38:15Speaker 01

  And, and so those, those things will be identical, because these are things we made and they're dyed. And there, there's nothing different about them. And so in, in industrialized society, we have, you know, everything, everything we've got is pretty much arbitrarily colored. But if you go to a non-industrialized group, that's not true. And so they don't, it's only they're not interested in color. If you, you bring bright colored things to them, they like them, just like we like them. Bright colors are great. They're beautiful. They are, but they just don't need to, no need to talk about them. They don't have.

• 38:46Lex Fridman?

  So probably color words is a good example of how language evolves from sort of function. When you need to communicate the use of something.

• 38:55Speaker 01

  I think so.

• 38:56Lex Fridman?

  Then you kind of invent different variations. And, uh, and basically you can imagine that the evolution of a language has to do with what the early tribes doing. Like what, what they want, what, what kind of problems are facing them and they're quickly figuring out how to efficiently communicate. The solution to those problems, whether it's aesthetic or function, all that kind of stuff, running away from a mammoth or whatever. But, you know, it's, so I think what you're pointing to is that we don't have data on the evolution of language. Because many languages are formed a long time ago, so you don't get the chatter.

• 39:29Speaker 01

  We have a little bit of like old English to modern English because there was a writing system. And we can see how, how old English looked. So the word order changed, for instance, in old English to middle English to modern English. And so it, you know, we could see things like that, but most languages don't even have a writing system. So of the 7,000, only, you know, a small subset of those have a writing system. And even if they have a writing system, they, it's not a very modern writing system. And so they don't have it. So we just basically have for Mandarin, for Chinese, we have a lot of, a lot of evidence from, from, for a long time and for English. And not for much else, not for in German a little bit, but not for a whole lot of like long-term language evolution. We don't have a lot. We just have snapshots is what we've got of current languages.

• 40:14Lex Fridman?

  Yeah, you get an inkling of that from the rapid communication on certain platforms like on Reddit. There's different communities and they'll come up with different slang, usually from my perspective, driven by a little bit of humor.

• 40:28Lex Fridman?

  Or maybe mockery or whatever it is, you know, just talking shit in different kinds of ways. And, uh, you could see the evolution of language there. Because, um, I think a lot of things on the internet, you don't want to be the boring mainstream. So you like want to deviate from the proper way of talking.

• 40:51Lex Fridman?

  And so you get a lot of deviation, like rapid deviation. Then when communities collide, you get like, just like you said, humans adapt to it. And you can see it through the lines of humor. I mean, it's very difficult to study, but you can imagine like 100 years from now. Well, if there's a new language born, for example, we'll get really high resolution data.

• 41:09Speaker 01

  I mean, English is changing. English changes all the time. All languages change all the time. So, you know, there's a famous result about the Queen's English. So the Queen, if you look at the Queen's vowels, the Queen's English is supposed to be, you know, originally the proper way for the talk was sort of defined by whoever the Queen talked or the King, whoever was in charge. And, uh, and, and so if you look at the, how her vowels changed, uh, from when she first became Queen in 1952 or 53, when she was coronated, the first, I mean, that's Queen Elizabeth, who's got, who died recently, of course, uh, until, you know, 50 years later, her vowels changed, her vowels shifted a lot. And so that, you know, even in the sounds of British English, in her, the way she was talking was changing.

• 41:55Speaker 01

  The vowels were changing slightly. So that's just in the sounds, there's change. I don't know what's, you know, we're, I'm interested, we're all interested in what's driving any of these changes. The, the word order of English changed a lot over a thousand years, right? So it used to look like German. You know, it looks, it used to be a verb final language with case marking and it shifted to a verb medial language, a lot of contact. So a lot of contact with French and it became a verb medial language with no case marking. And so it became this, you know, verb, verb initially thing. So, and so that's

• 42:26Lex Fridman?

  It's evolving.

• 42:27Speaker 01

  We had, it totally evolved. And so it may very, I mean, you know, it doesn't evolve maybe very much in 20 years is maybe what you're talking about, but over 50 and a hundred years, things change a lot, I think.

• 42:37Lex Fridman?

  We'll now have good data on it, which is great.

• 42:39Speaker 01

  That's for sure.

• 42:40Lex Fridman?

  Can you talk to what is syntax and what is grammar? So you wrote a book on syntax.

• 42:45Speaker 01

  I did. You were asking me before about what, you know, how do I figure out what a dependency structure is? I'd say the dependency structures aren't that hard generally. I think there's a lot of agreement of what they, of what they are for almost any sentence in, in most languages. I think people will agree on a lot of that.

• 43:02Speaker 01

  There are other parameters in the mix such that some people think there's a more complicated grammar than just a dependency structure. And so, you know, like Noam Chomsky, he's the most famous linguist ever. And he is famous for proposing a slightly more complicated syntax. And so, he invented phrase structure grammar. So, he's well-known for many, many things. But in the 50s, in early 60s, like, but late 50s, he was basically figuring out what's called formal language theory. So, and he figured out sort of a framework for figuring out how complicated language, you know, a certain type of language might

• 43:42Speaker 01

  be, so-called phrase structure grammars of language might be. And so, he, his, his idea was that maybe we can, we can think about the complexity of a language by how complicated the rules are. Okay. And the rules will look like this. They will have a left-hand side, and it'll have a right, right-hand side. Something on the left-hand side will expand to the thing on the right-hand side. So, we'll say we'll start with an S, which is like the root, which is a sentence. Okay. And then we're going to expand to things like a noun phrase and a verb phrase is what he would say, for instance. Okay. An S goes to an NP and a VP is a kind of a phrase structure rule. And then, and we figure out what an NP is. An NP is a determiner and a noun, for instance. And a verb, verb phrase

• 44:26Speaker 01

  is something else, is a verb and another noun phrase and another NP, for instance. Those are the rules of a very simple phrase structure. Okay. And, and so, he, he proposed phrase structure grammar as a way to sort of cover human languages. And then he actually figured out that, well, depending on the formalization of those grammars, you might get more complicated or less complicated languages. And so, you could, he could, he said, well, you, these are, these are things called, you know, context-free languages, that rule, that he thought, you know, human languages tend to be what he calls context-free languages. And, but there are simpler languages, which are so-called regular languages, and they have a more, a more constrained form to the rules of the, of the phrase structure

• 45:07Speaker 01

  of, of these particular rules. So, he, he basically discovered and kind of invented ways to describe the language. And those are phrase, those are phrase structure, a human language. And he was mostly interested in English initially in his, his work in the 50s.

• 45:23Lex Fridman?

  So, quick questions around all this. So, formal language theory is the big field of just studying language formally.

• 45:29Speaker 01

  Yes, and it doesn't have to be human language there. We can have a computer language is any kind of system which is generating a

• 45:38Speaker 01

  some set of

• 45:40Speaker 01

  expressions in a language and those could be like the the

• 45:45Speaker 01

  you know, the statements in a computer language, for example. So it could be that or it could be human language.

• 45:50Lex Fridman?

  So technically you can study programming languages.

• 45:52Speaker 01

  Yes, and have been heavily studied using this formalism. There's a big field of programming languages within the formal language.

• 46:00Lex Fridman?

  Okay, and then phrase structure grammar is this idea that you can break down language into this SNP VP like type of thing?

• 46:08Speaker 01

  It's a particular formalism for describing language. Okay, so and Chomsky was the first one. He's the one who figured that stuff out back in the 50s. And but he and that's equivalent. Actually, the context free grammar is actually is kind of equivalent in the sense that it generates the same sentences as a dependency grammar would. You know, as the dependency grammar is a little simpler in some way. You just have a root and it goes like we don't have any of these. The rules are implicit, I guess, in we just have connections between words. The free structure grammar is a kind of a different way to think about the dependency grammar. It's slightly more complicated, but it's kind of the same in some ways.

• 46:47Lex Fridman?

  So to clarify, dependency grammar is the framework under which you see language and you make the case that this is a good way to describe language.

• 46:57Speaker 01

  That's correct.

• 46:57Lex Fridman?

  And Noam Chomsky is watching. This is very upset right now. So it's just kidding. But what's the difference between where's the place of disagreement?

• 47:10Lex Fridman?

  Between phrase structure grammar and dependency grammar?

• 47:12Speaker 01

  They're very close. So phrase structure grammar and dependency grammar aren't that aren't that far apart. I like dependency grammar because it's more conspicuous. It's more transparent about representing the connections between the words. It's just a little harder to see in phrase structure grammar. You know, the place where Chomsky sort of devolved or went off from from this is he also thought there was Something called movement, okay? And so, and that's where we disagree. Okay, that's the place where I would say we disagree. And, and, and I mean, well, maybe we'll get into that later. But the idea is, if you wanna, do you want me to explain that now?

• 47:48Lex Fridman?

  I would love, can you explain movement?

• 47:49Speaker 01

  Movement, okay.

• 47:50Lex Fridman?

  You're saying so many interesting things.

• 47:52Speaker 01

  Okay, so here's the movement is Chomsky basically sees English. And he says, okay, I said, um, you know, we had that sentence early. Like, it was like two dogs entered the room. It's changed a little bit, say, two dogs will enter the room. And he notices that, hey, English, if I want to make a question, a yes, no question from that same sentence, I say, instead of two dogs will enter the room, I say, will two dogs enter the room? Okay, there's a different way to say the same idea. And it's like, well, the auxiliary verb, that will thing, it's at the front as opposed to in the middle, okay? And so, and he looked, you know, if you look at English, you see that that's true for all those modal verbs and for other kinds of auxiliary verbs in English. You always do that. You always put an auxiliary verb at the front.

• 48:36Speaker 01

  And, and what he, when he saw that, so, you know, if I say, um, I can win this bet, can I win this bet, right? So I move the can to the front. So, actually, that's a theory. I just gave you a theory there. He, he talks about it as movement. That word in the declarative is the root, is the sort of default way to think about the sentence, and you move the auxiliary verb to the front. That's a movement theory, okay? And he just thought that was just so obvious that it must be true, that, that, that there's nothing more to say about that, that this is how auxiliary verbs work in English. There's a movement rule such that you're move, like to get from the declarative to the interrogative, you're moving the auxiliary to the front. And it's a little more complicated as soon as you go to simple, simple present and simple

• 49:21Speaker 01

  past, because, you know, if I say, you know, John slept, you have to say, did John sleep? Not slept John, right? And so, you have to somehow get an auxiliary verb. And I guess underlyingly, it's like slept is, it's a little more complicated than that, but his, that's his idea, there's a movement, okay? And, and so, a different way to think about that, that isn't, I mean, then, then he ended up showing later. So he proposed this theory of grammar, which has movement. There's other places. Where he thought there's movement, not just auxiliary verbs, but things like the passive in English and things like questions, WH questions, a bunch of places where he thought there's also movement going on. And each one of those, he thinks there's words, well, phrases and words are moving around from one structure to another, what you call deep structure to surface structure.

• 50:05Speaker 01

  I mean, there's like two different structures in his in his theory. Okay. There's a different way to think about this, which is there's no movement at all. There's a lexical copying rule such that the word will or the word can, these auxiliary verbs, they just have two forms. And one of them is the declarative and one of them is interrogative. And you basically have the declarative one and, oh, I form the interrogative or I can form one from the other, doesn't matter which direction you go. And I just have a new entry, which has the same meaning, which has a slightly different argument structure. Argument structure is just a fancy word for the ordering of the words. And so if I say, you know, it was the dogs, two dogs can or will enter the room.

• 50:50Speaker 01

  There's two forms of will. One is will declarative. And then, okay, I've got my subject to the left. It comes before me and the verb comes after me in that one. And then the will interrogative is like, oh, I go first. Interrogative will is first and then I have the subject immediately after and then the verb after that. And so you can just generate from one of those words, another word with a slightly different argument structure with different ordering.

• 51:17Lex Fridman?

  And these are just lexical copies.

• 51:19Speaker 01

  And they're just.

• 51:20Lex Fridman?

  They're not necessarily moving from one to another.

• 51:22Speaker 01

  There's no movement.

• 51:22Lex Fridman?

  There's a romantic notion that you have like one main way to use a word and then you could move it around.

• 51:29Speaker 01

  Right, right.

• 51:30Lex Fridman?

  Which is essentially what movement is implying.

• 51:32Speaker 01

  Yeah, but that's the lexical copying is similar. So then we do lexical copying for that same idea that maybe the declarative is the source and then we can copy it. And so an advantage, there's multiple advantages of the lexical copying story. It's not my story. This is like Ivan Sog, linguists, a bunch of linguists have been proposing these stories as well, you know, in tandem. With the movement story, okay, you know, Ivan Sog died a while ago, but he was one of the proponents of the non-movement with lexical copying story. And so that is that a great advantage is, well, Chomsky, really famously in 1971, showed that the movement story leads to

• 52:16Speaker 01

  learnability problems. It leads to problems for how language is learned. It's really, really hard to figure out what the underlying structure of a language is if you have both phrase structure and movement. It's like really hard to figure out what came from what. There's like a lot of possibilities there. If you don't have that problem, the learning problem gets a lot easier.

• 52:36Lex Fridman?

  Just say there's lexical copies.

• 52:38Speaker 01

  Yeah.

• 52:39Lex Fridman?

  And when we say the learning problem, do you mean like humans learning a new language?

• 52:42Speaker 01

  Yeah, just learning English. So baby is lying around, listening to the crib, listening to me talk. And, you know, how are they learning English? Or, you know, maybe it's a two-year-old who's learning, you know, interrogatives and stuff, or one, you know, how are they doing that? Are they doing it from, like, are they figuring out? Or, like, you know, so Chomsky said it's impossible to figure it out, actually. He said it's actually impossible, not hard, but impossible. And therefore, that's where universal grammar comes from, is that it has to be built in. And so what they're learning is that there's some built-in, movement is built in, in his story, is absolutely part of your language module. And then you are, you're just setting parameters. You're setting, depending on

• 53:26Speaker 01

  English is just sort of a variant of the universal grammar. And you're figuring out, oh, which orders does English do these things? That's, the non-movement story doesn't have this. It's like much more bottom-up. You're learning rules. You're learning rules one by one. And, oh, this word is connected to that word. A great advantage, another advantage, it's learnable. Another advantage of it is that it predicts that not all auxiliaries might move. Like, it might depend on the word, depending on whether you, and that turns out to be true. So there's words that, that don't really work as auxiliary, they work in declarative and not in interrogative. So I can say, I'll give you the opposite first. If

• 54:09Speaker 01

  I can say, aren't I invited to the party? Okay. And that's an interrogative form. But it's not from, I aren't invited to the party. There is no I aren't, right? So that's interrogative only. And then we also have forms like ought. I ought to do this. And I guess some British, old British people can say.

• 54:31Lex Fridman?

  Ought I?

• 54:31Speaker 01

  Exactly. It doesn't sound right, does it? For me, it sounds ridiculous. I don't even think ought is great, but I mean, I totally recognize I ought to do. I think it's not too bad, actually. I can say I ought to do this. That sounds pretty good.

• 54:41Lex Fridman?

  Ought I? If I'm trying to sound sophisticated, maybe.

• 54:44Speaker 01

  I don't know. It just sounds completely out to me.

• 54:46Lex Fridman?

  Ought I?

• 54:46Speaker 01

  Yeah. Anyway, so there are variants here. And a lot of these words just work in one versus the other. And that's like, fine, under the lexical copying story. It's like, well, you just learn the usage. Whatever the usage is, is what you do with this word. But it doesn't, it's a little bit harder in the movement story. The movement story, like, that's an advantage, I think, of lexical copying. And in all these different places, there's all these usage variants, which make the movement story a little bit harder to work.

• 55:19Lex Fridman?

  So one of the main divisions here is the movement story versus the lexical copy story.

• 55:23Speaker 01

  That's right.

• 55:23Lex Fridman?

  That has to do about the auxiliary words and so on. But rewind to the phrase structure grammar.

• 55:30Speaker 01

  Yeah.

• 55:30Lex Fridman?

  Versus dependency grammar.

• 55:32Speaker 01

  Those are equivalent in some sense in that for any dependency grammar, I can generate a phrase structure grammar, which generates exactly the same sentences. I just like the dependency grammar formalism because it makes something really salient, which is the lengths of dependencies between words, which isn't so obvious in the phrase structure. In the phrase structure, it's just kind of hard to see. It's in there. It's just very, very, it's opaque.

• 56:01Lex Fridman?

  Technically, I think phrase structure grammar is mappable to dependency grammar.

• 56:04Speaker 01

  And vice versa.

• 56:05Lex Fridman?

  And vice versa.

• 56:06Speaker 01

  Yeah.

• 56:06Lex Fridman?

  But there's like these little labels, S and PVP.

• 56:09Speaker 01

  Yeah. For a particular dependency grammar, you can make a phrase structure grammar, which generates exactly those same sentences and vice versa. But there are many phrase structure grammars, which you can't really make a dependency grammar. I mean, you can do a lot more in a phrase structure grammar. You get many more of these extra nodes, basically. You can have more structure in there. And some people like that. And maybe there's value to that. I don't like it.

• 56:35Lex Fridman?

  Well, for you, so we should clarify. So dependency grammar is just, well, one word depends on only one other word and you form these trees.

• 56:44Speaker 01

  Yes.

• 56:44Lex Fridman?

  And that makes, it really puts priority on those dependencies, just like as a, as a tree that you can then measure the distance of the dependency from one word to the other. They can then map to the cognitive processing of the, of the sentences, how well, how easy it is to understand and all that kind of stuff. So it just puts the focus on, just like the mathematical, um, uh, distance of dependence between words. So like, it's just a different focus.

• 57:14Speaker 01

  Absolutely.

• 57:14Lex Fridman?

  Just continue on a thread of Chomsky, because it's really interesting, because as you're discussing disagreement, to the degree there's disagreement, you're also telling the history of the study of language, which is really awesome. So you mentioned context free versus regular. Does that distinction come into play for dependency grammars?

• 57:34Speaker 01

  No, not at all. I mean, regular, regular languages are too simple for human languages. They, they are, uh, they, it's a part of the hierarchy, but human languages are, in, in the phrase structure world are definite, they, they're at least context free. Maybe a little bit more, a little bit harder than that. But, uh, so there's something called context sensitive as well, where you can have, like this is the, just the formal language description. In, in a context free grammar, you have one, this is like a bunch of like formal language theory we're doing here.

• 58:08Lex Fridman?

  I love it.

• 58:09Speaker 01

  Okay. So you have, you have a left hand side category and you're expanding to anything on the right is, is a, uh, that's a context free. So like, the idea is that that category on the left expands in independent of context to those things, whatever they are on the right, doesn't matter what. And, and a context sensitive says, okay, I, I actually have more than one thing on the left. I can tell you only in this context, you know, I have, maybe you have like a left and a right context, or just a left context or a right context. I have two or more stuff on the left tells you how to expand that, those things in that way. Okay. So it's context sensitive. A, a regular language is just more constrained. And so it, it doesn't allow anything on the right.

• 58:49Speaker 01

  It, it allows very, it, it allows, basically it's a, one very complicated rule is kind of what a, a, a regular language is. And so it doesn't have any. I was gonna say, long-distance dependencies. It doesn't allow recursion, for instance. There's no recursion. Yeah, recursion is where you... Which is, human languages have recursion. They have embedding. And you can't... Well, eh, it doesn't allow center-embedded recursion, which human languages have, which is what... Center-embedded recursion. So, within a sentence? Within a sentence. Yeah, within a sentence. So here, we're gonna get to that. But I... You know, the formal language stuff is a little aside. Chomsky wasn't proposing it for human languages, even. He was just pointing out that human languages are context-free. And then he was most in... For human... Because that was kinda stuff he did for formal languages.

• 59:32Speaker 01

  And what he was most interested in was human language. And that's like, the movement is where we... Where he sort of set off in on the, I would say, a very interesting, but wrong foot. It was kind of interesting. It's a very... I agree, it's kind of a very interesting history. So there's this... So he proposed this multiple theories in 57, and then 65. They all have this framework, though, was phrase structure plus movement. Different versions of the phrase structure and the movement in the 57. These are the most famous, original bits of Chomsky's work. And then 71 is when he figured out that those lead to learning problems. That there's cases where a kid could never figure out which rule... Which set of rules was intended. And so... And then he said, "Well, that means it's innate."

• 1:00:17Speaker 01

  It's kind of interesting. He just really thought the movement was just so obviously true that he couldn't... He didn't even entertain giving it up. It's just obvious that that's obviously right. And it was later where people figured out that there's all these, like, subtle ways in which things which look like generalizations aren't generalizations. And they, you know, across the category, they're word-specific, and they have... And they kinda work, but they don't work across various other words in the category. And so it's easier to just think of these things as lexical copies. And I think he was very obsessed... I don't know. I'm guessing that he just... He really wanted this story to be simple in some sense. And language is a little more complicated in some sense, you know? He didn't like words. He never talks about words.

• 1:01:01Speaker 01

  He likes to talk about combinations of words. And words are... You know, look up a dictionary. There's 50 senses for a common word, right? The word "take" will have 30 or 40 senses in it. So, uh, there'll be many different senses for common words. And he just doesn't think about that. It's... Or it doesn't... Think that's language. I think he doesn't think that's language. He thinks that words are distinct from combinations of words. I think they're the same. If you look at my brain in the scanner while I'm listening to a language I understand, and you compare, I can localize my language network in a few minutes, in like 15 minutes. And what you do is I listen to a language I know, I listen to, you know, maybe some language I don't know, or I listen to muffled speech,

• 1:01:45Speaker 01

  or I read sentences, and I read non-words. Like, I do anything like this, anything that's sort of really like English, and anything that's not very like English. So I've got something like it and not, and I got a control. And the voxels, which is just, you know, the 3D pixels in my, in my brain, that are responding most are, is a language area. And, and that's this left lateralized area in my head. And, and wherever I look in that network, if you look for the combinations versus the words, it's there, it's everywhere. It's the same.

• 1:02:18Lex Fridman?

  That's fascinating.

• 1:02:19Speaker 01

  And, and so it's like hard to find, there are no areas that we know. I mean, that's, it's a little overstated right now. At this, at this point, the, the technology isn't great. It's not bad, but we have the best, the best way to figure out what's going on in my brain when I'm listening or reading language is to use FMRI, functional magnetic resonance imaging. And that's a very good localization method. So I can figure out where exactly these signals are coming from, pretty, you know, down to, you know, millimeters, you know, cubic millimeters or smaller, okay? Very small. We can figure those out very well. The problem is the when, okay? It's, it's measuring oxygen, okay? And oxygen takes a little while to get to those cells. And so it takes on the order of seconds.

• 1:03:00Speaker 01

  So I talk fast, I probably listen fast, and I can probably understand things really fast. So a lot of stuff happens in two seconds. And so to say that we know what's going on, that the words, right now, in that network, our best guess is that whole network is doing something similar, but maybe different parts of that network are doing different things. And, and that's probably the case. We just don't have very good methods to figure that out, right, at this moment. And so.

• 1:03:28Lex Fridman?

  Since we're kind of talking about the history of the study of language, what other interesting disagreements, and you're both at MIT or were for a long time, what kind of interesting disagreements there, tensions of ideas are there between you and Noam Chomsky? And we should say that Noam was in the linguistics department and you're, I guess for a time were affiliated there, but primarily a brain and cognitive science department, which is another way of studying language. And you've been talking about fMRI. So like, what, is there something else interesting to bring to the surface about the disagreement between the two of you? Or other people in the...

• 1:04:08Speaker 01

  Yeah, I mean, I've been at MIT for 31 years, since 1993, and he, Chomsky's been there much longer. So I met him, I knew him, I met when I first got there, I guess, and I, and we would interact every now and then. I'd say that, so I'd say our, our biggest difference is our methods. And so that's the biggest difference between me and Noam, is that I gather data from people. I do experiments with people and I gather corpus data, whatever, whatever corpus data is available. And we do quantitative methods to evaluate any kind of hypothesis we have.

• 1:04:48Speaker 01

  He just doesn't do that. And so, you know, you, you know, he has never once been associated with any experiment or corpus work ever. And so it's all thought experiments. It's his own intuitions. So I just don't think that's the way to do things. That's a, that's a, you know, across the street, they're across the street from us, kind of difference between brain and cognizant and linguistics. I mean, not all linguists, some of the linguists, depending on what you do, more speech oriented, they do more quantitative stuff, but in the, in the meaning, words and, well, it's combinations of words, syntax, semantics, they tend not to do experiments and...

• 1:05:28Speaker 01

  And corpus analyses.

• 1:05:29Lex Fridman?

  So linguistic size, probably, well, but the method is a symptom of a bigger approach, which is sort of a psychology philosophy side on Gnome. And for you, it's more sort of data driven. So almost like mathematical approach.

• 1:05:43Speaker 01

  Yeah, I mean, I'm psychologist. So I would say we're in psychology. You know, I'm in brain cognitive sciences is MIT's old psychology department. It was the psychology department up until 1985, and it became the brain and cognitive science department. And so I, I mean, my training isn't psycho. I mean, my training is math and computer science, but I'm a psychologist. I mean, I mean, I don't know what I am.

• 1:06:04Lex Fridman?

  So data driven psychologist.

• 1:06:05Speaker 01

  Yeah, yeah, yeah.

• 1:06:06Lex Fridman?

  You are.

• 1:06:07Speaker 01

  I am what I am, but I'm happy to be called a linguist. I'm happy to be called a computer scientist. I'm happy to be called psychologist, any of those things.

• 1:06:13Lex Fridman?

  But in the actual, like how that manifests itself outside of the methodology is like these differences, these subtle differences about the movement story versus the lexical copy story.

• 1:06:23Speaker 01

  Yeah, those are theories, right? So the theories are, but I think the reason we differ in part is because of how we evaluate the theories. And so I evaluate theories quantitatively and Gnome doesn't.

• 1:06:38Lex Fridman?

  Got it. Okay, well, let's, let's explore the theories that you explore in your book. Let's return to this dependency grammar framework of looking at language. What's a good justification why the dependency grammar framework is a good way to explain language? What's your intuition?

• 1:06:56Speaker 01

  So the reason I like dependency grammar, as I've said before, is that it's very transparent about its representation of distance between words. So it's like, all it is, is you've got a bunch of words, you're connecting them together to make a sentence. And a really neat insight, which turns out to be true, is that the further apart the pair of words are that you're connecting, the harder it is to do the production, the harder it is to do the comprehension. It's harder to produce, it's hard to understand when the words are far apart. When they're close together, it's easy to produce and it's easy to comprehend. Let me give you an example. Okay, so. We have, in any language, we have mostly local connections between words, but they're abstract.

• 1:07:41Speaker 01

  The connections are abstracted between categories of words. And so you can always make things further apart if you put your, if you add modification, for example, after a noun. So a noun in English comes before a verb. The subject noun comes before a verb. And then there's an object after, for example. So I can say what I said before, you know, the dog entered the room or something like that. So I can modify dog. If I say something more about dog after it, then what I'm doing is indirectly, I'm lengthening the dependence between dog and entered by adding more stuff to it. So I just make it explicit here.

• 1:08:19Speaker 01

  If I say, um, uh, the, the boy who the cat scratched cried. We're going to have a mean cat here. And, uh, and so what I've got here is I get the boy cried. It would be a very short, simple sentence. And I just told you something about the, the boy. And I told you it was, it was the boy who the cat scratched. Okay.

• 1:08:41Lex Fridman?

  So the cried is connected to the boy. The cried at the end is connected to the boy in the beginning.

• 1:08:45Speaker 01

  Right. And so I can do that and I can say that that's a perfectly fine English sentence. And I can say the cat which the dog chased ran away or something. Okay, I can do that, but it's really, and so I, but it's really hard now. I've got, you know, whatever I have here, I have the boy who the cat. Now let's say I try to modify cat. Okay, the boy who the cat which the dog chased scratched ran away. Oh my God, that's hard, right? I can, I'm sort of just working that through in my head, how to produce and how to, and it's really very just horrendous to understand. It's not so bad. At least I've got intonation there to sort of mark the boundaries and stuff. But it's, that's really complicated. That's sort of English in a way.

• 1:09:29Speaker 01

  I mean, that follows the rules of English. But, uh, so what's interesting about that is, is that what I'm doing is nesting dependencies there. I'm putting one, I've got a subject connected to a verb there. And then I'm modifying that with a clause, another clause, which happens to have a subject and a verb relation. I'm trying to do that again on the second one. And what that does is it lengthens out the dependence. Multiple dependents actually get lengthened out there. The dependencies get, get longer, longer on the outside ones get long. And even the ones in between get kind of long. And, and, and you just, so what's fascinating is that. That's bad. That's really horrendous in English. But that's horrendous in any language. And so in no matter what language you look at, if you do, just figure out some structure where I'm going to have some modification

• 1:10:14Speaker 01

  following some head which is connected to some later head, and I do it again, it won't be good. Guaranteed. Like 100%, that will be unintelligible in that language in the same way that was unintelligible in English.

• 1:10:26Lex Fridman?

  Let's just clarify, the distance of the dependencies is whenever the boy cried, there's a dependence between two words, and then you're counting the number of what, morphemes between them?

• 1:10:41Speaker 01

  That's a good question. I just say words. Your words are morphemes between. We don't know that. Actually, that's a very good question. What is the distance metric? But let's just say it's words. Sure.

• 1:10:49Lex Fridman?

  So, and you're saying the longer the distance of that dependence, the more, no matter the language, except legal ease.

• 1:10:57Speaker 01

  Even legal ease.

• 1:10:58Lex Fridman?

  Even legal ease. We'll talk about it. Okay, okay, okay. But that, the people will be very upset that speak that language. Not upset, but they'll either not understand it, or they'll be like, this is, their brain will be working in overtime.

• 1:11:13Speaker 01

  Yeah. They will have a hard time either producing or comprehending it. They might tell you that's not their language. You know, it's sort of the language. I mean, it's following, like, they'll agree with each of those pieces as part of their language, but somehow that combination will be very, very difficult to produce and understand.

• 1:11:28Lex Fridman?

  Is that a chicken or the egg issue here? So like, is...

• 1:11:31Speaker 01

  Well, I'm giving you an explanation. So, I mean, I'm giving you two kinds of explanations. I'm telling you that center embedding, that's nesting, those are the same, those are synonyms for the same concept here. And the explanation for what, those are always hard. Center embedding and nesting are always hard. And I gave you an explanation for why they might be hard, which is long distance connections. There's a, when you do center embedding, when you do nesting, you always have long distance connections between the dependents. You just, and so that's not necessarily the right explanation. It just hap, I can go through reasons why that's probably a good explanation. And it's not really just about one of them. So probably it's a pair of them or something of these dependents that you get along that drives you to like be really confused in that case. And so what the behavioral consequence there,

• 1:12:16Speaker 01

  I mean, we... This is kind of methods, like, how do we get at this? You could try to do experiments to get people to produce these things. They're gonna have a hard time producing them. You can try to do experiments to get them to understand them and you get, you see how well they understand them, can they understand them? Another method you can do is give people partial materials and ask them to complete them, you know, those, those center embedded materials and they, they'll fail. So I've done that, I've done all these kinds of things.

• 1:12:44Lex Fridman?

  So, so, so, wait a minute, so, so central embedding, meaning, like, you take a normal sentence, like, boy cried, and inject a bunch of crap in the middle.

• 1:12:51Speaker 01

  Yes.

• 1:12:52Lex Fridman?

  That separates the boy and the cried.

• 1:12:54Speaker 01

  Yes.

• 1:12:55Lex Fridman?

  Okay, that's central embedding, and nesting is on top of that?

• 1:12:58Speaker 01

  No, no, nesting is the same thing. Central embedding, those are totally equivalent terms, I'm sorry, I sometimes use one and sometimes use the other.

• 1:13:03Lex Fridman?

  Ah, got it, got it.

• 1:13:04Speaker 01

  They don't mean anything different.

• 1:13:05Lex Fridman?

  Got it. And then, uh, what you're saying is there's a bunch of different kinds of experiments you can do. I mean, I like the understanding one, is like, have more embedding, more central embedding, is it easier or harder to understand? But then you have to measure the level of understanding, I guess?

• 1:13:19Speaker 01

  Yeah, yeah, you could. I mean, there's multiple ways to do that. I mean, there's, there's the simplest way is just ask people, how good is this sound? How natural is this sound? That's a very blunt, but very good measure. If it's very, very reliable, people will do the same thing. And so, it's like, I don't know what it means exactly, but it's doing something, such that we're measuring something about the confusion, the difficulty associated with those.

• 1:13:38Lex Fridman?

  And those, like, those are giving you a signal, that's why you can say them.

• 1:13:41Speaker 01

  Yeah, yeah.

• 1:13:42Lex Fridman?

  Okay. What about the, the completion of this, with the central embedding?

• 1:13:45Speaker 01

  So if you give them a partial sentence, say I say, um, "The book which the author who," and I ask you to now finish that off for me. I mean, either say it. Yeah, yeah, but you can just, but say it's written in front of you, and you can just type in, have as much time as you want. They will, even though that one's not too hard, right? So if I say, it's like, "The book," it's like, oh, "The, the book which the author who I met wrote." Was good, you know, that's a very simple completion for that. You know, if I give that completion on online somewhere to a, you know, a crowdsourcing platform and ask people to complete that, they will miss off of a verb very regularly, like half the time, maybe two thirds of the time, they'll say, they'll just leave off one of those phrases, even with that simple, so say, the book,

• 1:14:31Speaker 01

  which the author, who, and they'll say, was,

• 1:14:38Speaker 01

  they won't, you need three verbs, right? I need three verbs, or who I met, wrote, was good, and they'll give me two. They'll say, who was, who was famous was good, or something like that. They'll just give me two. And that'll happen about 60% of the time. So 40%, maybe 30%, they'll do it correctly, correctly, meaning they'll do a three verb phrase. I don't know what's correct or not, you know, this is hard. It's a hard task.

• 1:15:00Lex Fridman?

  Yeah, I actually am struggling with it in my head.

• 1:15:02Speaker 01

  Yeah, well, it's easier.

• 1:15:03Lex Fridman?

  When you, when you stare at it.

• 1:15:05Speaker 01

  If you look, it's a little easier than listening, it's pretty tough, because you have to, because there's no trace of it. You have to remember the words that I'm saying, which is very hard auditorily. We wouldn't do it this way. We do it written, you can look at it and figure it out. It's easier in many dimensions in some ways, depending on the person. It's easier to gather written data for, I mean, most sort of psycho, I work in psycholinguistics, right? Psychology of language and stuff. And so, a lot of our work is based on written stuff, because it's so easy to gather data from people doing written kinds of tasks. Spoken tasks are just more complicated to administer and analyze, because people do weird things when they speak, and it's harder to analyze what they do. But they, they generally point to the same kinds of things.

• 1:15:50Lex Fridman?

  So, okay, so the Universal Theory of Language.

• 1:15:52Speaker 01

  Yeah.

• 1:15:53Lex Fridman?

  By Ted Gibson is that you can form dependency, you can form trees for many sentences.

• 1:16:00Speaker 01

  That's right.

• 1:16:01Lex Fridman?

  You can measure the distance in some way of those dependencies, and then you can say that most languages have very short dependencies.

• 1:16:10Speaker 01

  All languages.

• 1:16:11Lex Fridman?

  All languages.

• 1:16:11Speaker 01

  All languages have short dependencies. You can actually measure that. So, an ex-student of mine, this guy is at University of California, Irvine. Richard Futrell did a thing a bunch of years ago now where he looked at all the languages we could look at, which was about 40 initially, and now I think there's about 60 for which there are dependency structures. Like, so there, meaning there's got to be like a big text, a bunch of texts which have been parsed for their dependency structures. And there's about 60 of those which have been parsed that way. And for all of those, you can, what he did was take any, any sentence in one of those languages, and, and you can do the dependency structure and then start at the root. We were, we're talking about dependency structures, that's pretty easy now.

• 1:16:54Speaker 01

  And, and he's trying to figure out what a control way you might say the same sentence is in that language. And so he's just like, all right, there's a root and it has, say as a sentence is, um, let's go back to, you know, two dogs entered the room. And so entered is the root and entered has two dependents. It's got dogs and it has room. Okay. And what he did is like, let's scramble that order. Let's three things, the root and the, the head and the two dependents in, in just some random order, just random. And then just do that for all the dependents down the, so now look, do it for the, and whatever was two and dogs and for, uh, and room. And, and that's, you know, that's not, it's a very short sentence. When sentences get longer and you have more dependents, there's more scrambling that's possible.

• 1:17:38Speaker 01

  And what he found what, so that, so, so that's one, you could figure out one scrambling for that sentence. He did it like a hundred times for every sentence and every corp, and every one of these texts, every corpus. And, and then he just compared the dependency lengths in those random scramblings to what actually happened, what, what the, the English or the French or the German was in the, in original language or Chinese, or what all these like 80, you know, 60 languages. Okay. And, and the dependency lengths are always shorter in the real language compared to, to this, this kind of a control. And there's another, it's, it's a little more rigid, his control. So, um, The way I described it, you could have crossed dependencies. Like by scrambling that way, you could scramble in any way at all. Languages don't do that.

• 1:18:23Speaker 01

  They tend not to cross dependencies very much. Like, so the dependency structure, they just, they tend to keep things non-crossed. And there's a, you know, there's a technical term, they call that projective. But it's just non-crossed is all that is projective. And so if you just constrain the scrambling so that it only gives you projective, sort of non-crossed, the same thing holds. So it's, so the, you still, still, human languages are much shorter than these, this kind of a control. So there's like, what it means is that, that we're, in every language, we're trying to put things close relative to this kind of a control. Like, it doesn't matter about the word order. Some of these are verb finals, some of them use a verb medial like English. And some are even verb initial.

• 1:19:04Speaker 01

  There are a few languages of the world which have VSO, word order, verb, subject, object languages. I haven't talked about those. It's like 10% of the.

• 1:19:13Lex Fridman?

  And even, even in those languages, it's still short dependencies.

• 1:19:17Speaker 01

  Short dependencies is rules.

• 1:19:19Lex Fridman?

  Okay, so how, what, what are some possible explanations for that? For why, why languages have evolved that way? So that, that's one of the, I suppose disagreements you might have with Chomsky. So you consider the evolution of language in, in terms of information theory.

• 1:19:37Speaker 01

  Yeah.

• 1:19:38Lex Fridman?

  And for you, the purpose of language is ease of communication, right? And processing.

• 1:19:44Speaker 01

  That's right. That's right. So, I mean, the, the story here is just about communication. It is just about production, really. It's about ease of production is the story.

• 1:19:53Lex Fridman?

  When you say production, can you?

• 1:19:55Speaker 01

  Oh, I just mean ease of language production. It's easier for me to say things when the, what I'm doing whenever I'm talking to you is somehow I'm formulating some idea in my head and I'm putting these words together. And it's easier for me to do that. To put, to say something where the words are closely connected in a dependency, as opposed to separated, like by putting something in between and over and over again. It's just hard for me to keep that in my head. Like, that's, that's the whole story. Like, the story is basically, it's like the dependency grammar sort of gives that to you, like, just like, long, long is bad, short is good. It's like, easier to keep in mind, because you have to keep it in mind for, probably for production, you know, probably matters in comprehension as well, like, also matters in comprehension.

• 1:20:38Lex Fridman?

  It's on both sides of it. The production and the...

• 1:20:40Speaker 01

  But I would guess it's probably evolved for production. It's about producing. It's about what's easier for me to say, that ends up being easier for you also. That's very hard to disentangle, this idea of who is it for? Is it for me, the speaker? Or is it for you, the listener? I mean, part of my language is for you. Like, the way I talk to you is going to be different from how I talk to different people. I'm definitely angling what I'm saying to who I'm saying, right? It's not like I'm just talking the same way to every single person. And so, I am sensitive to my audience. But, how, does that, does that, you know, work itself out in the, in the dependency length differences? I don't know. Maybe that's about just the words, that part, you know, which words I select?

• 1:21:20Lex Fridman?

  My initial intuition is that you optimize language for the audience.

• 1:21:25Speaker 01

  Yeah.

• 1:21:26Lex Fridman?

  But...

• 1:21:27Speaker 01

  But it's both.

• 1:21:27Lex Fridman?

  It's just kind of like messing with my head a little bit, to say that some of the optimization might be, or maybe the primary objective of the optimization might be the ease of production.

• 1:21:36Speaker 01

  Yeah, and we have different senses, I guess. I'm, I'm like, very selfish. And you're like, I'm like, I think it's like, it's all about me. I'm like, I'm just doing this easiest for me at all times. I don't want, I'm like, I'll, I mean, but I have to, of course, choose the words that I think you're gonna know. I'm not gonna choose words you don't know. In fact, I'm gonna fix that when I, you know, so there, it's about, but, but maybe for, for the syntax, for the combinations, it's just about me. I feel like it's, I don't know, though. It's very hard to...

• 1:22:04Lex Fridman?

  Wait, wait, wait, but the purpose of communication is to be understood, is to convince others and so on. So, like, the selfish thing is to be understood.

• 1:22:11Speaker 01

  Okay, yeah, it's, it's a little circular there, too, then, okay.

• 1:22:14Lex Fridman?

  Right. I mean, like, the ease of production...

• 1:22:17Speaker 01

  Helps, helps me be understood, then.

• 1:22:20Speaker 01

  I don't think it's circular. So I want what's

• 1:22:22Lex Fridman?

  I think the primary, I think the primary objective is to be understood is about the listener. Cause otherwise, the, if you're optimizing for the ease of production, then you're, you're not going to have any of the interesting complexity of language. Like you're trying to like explain.

• 1:22:35Speaker 01

  Well, let's control for what it is I want to say. Like I, I'm saying, let's control for the thing, the, the message, control for the message.

• 1:22:41Lex Fridman?

  But that means the message needs to be understood. That's the goal.

• 1:22:44Speaker 01

  Oh, but that's the meaning. So I'm still talking about the form, just the form of the meaning. How do I frame the form of the meaning is all I'm talking about. You're talking about a harder thing. I think it's like, how am I like trying to change the, let's, let's keep the meaning constant. Like which, if you keep the meaning constant, how can I phrase whatever it is I need to say? Like I gotta pick the right words and I'm going to pick the order so that it's, so it's easy for me. You know, that's, that's, that's, that's what I think is probably like.

• 1:23:12Lex Fridman?

  I think I'm still tying meaning and form together in my head. But you're saying if you keep the meaning of what you're saying constant.

• 1:23:21Speaker 01

  Yeah.

• 1:23:21Lex Fridman?

  What the optimization, yeah, it could be the primary objective of that optimization is the, for production. That's interesting. I'm, I'm struggling to keep constant the meaning. It's just so, I mean, I'm such a, I'm a human, right? So for me, the form, without having introspected on this, the form and the meaning are tied together, like deeply, because I'm a human. Like for, for me, when I'm speaking, cause I haven't thought about language, like in a rigorous way, about the form of language.

• 1:23:56Speaker 01

  But look, for any event, there's, there's an unbounded, I don't, I don't want to say infinite, but sort of unbounded ways of that I might communicate that same event. This two dogs entered a room. I can say in many, many different ways. I can say, hey, there's two dogs. They entered the room. Hey, the room was entered by something. The thing that was entered was two dogs. I mean, there's, I mean, it's kind of awkward and weird and stuff. But those are all similar messages with different forms, but different ways I might frame. And of course, I use the same words there all the time. I could have referred to the dogs as, you know, a dalmatian and a poodle or something. You know, I could have been more specific or less specific about what they are. And I could have said, been more abstract about, about, about the number.

• 1:24:40Speaker 01

  There's like, so I, like, I'm trying to keep the meaning, which is this event, constant. And then how am I going to describe that to get that to you? It kind of depends on what you need to know, right? And what I think you need to know. But I'm like, let's get control for all that stuff and not, and it's like, I'm just like choosing, but I'm doing something simpler than you're doing, which is just forms.

• 1:25:00Lex Fridman?

  Yes.

• 1:25:01Speaker 01

  Just words.

• 1:25:02Lex Fridman?

  To you specifying the species, the, the breed of dog and whether they're cute or not is changing the meaning.

• 1:25:10Speaker 01

  That might be, yeah. Yeah, that would be changing. Well, that would be changing the meaning for sure.

• 1:25:13Lex Fridman?

  Right, so you're just, yeah, yeah, yeah.

• 1:25:16Speaker 01

  That's changing the meaning. But say, even if we keep that constant, we can still talk about what's easier or hard for me, right? The listener and the, and the, right? Which phrase structures I use, which combinations, which, you know.

• 1:25:28Lex Fridman?

  This is so fascinating and just like a, a really powerful window into human language. But I wonder still throughout this, how vast the gap between meaning and form. I just, I just have this like, maybe romanticized notion that they're close together, that they evolve close to like hand in hand. That you can't just simply optimize for one without the other being in the room with us. Like, it's, well, it's kind of like an iceberg. Form is the tip of the iceberg and the rest, the, the meaning is the iceberg, but you can't like separate.

• 1:26:05Speaker 01

  But I think that's why these large language models are so successful is because they're good at form and form isn't that hard. In some sense, and meaning is tough still. And that's why they're not, they're, you know, they don't understand what they're, we're going to talk about that later maybe. But like, we can distinguish. In our, forget about large language models, like humans, maybe you'll talk about that later too, is like the difference between language, which is a communication system, and thinking, which is meaning. So, language is a communication system for the meaning, it's not the meaning. And so that's why, I mean, and there's a lot of interesting evidence we can talk about relevant to that.

• 1:26:44Lex Fridman?

  Well, I mean, that's a really interesting question. What is the difference between language, written, communicated, versus thought? What to use the difference between them?

• 1:26:58Speaker 01

  Well, you, or anyone, has to think of a task which they think is a good thinking task. And there's lots and lots of tasks which should be good thinking tasks. And whatever those tasks are, let's say it's, you know, playing chess, or that's a good thinking task, or playing some game, or doing some complex puzzles, maybe remembering some digits, that's thinking, remembering some, a lot of different tasks we might think, maybe just listening to music is thinking, or, there's a lot of different tasks we might think of as thinking. There's a woman in my department at Federencio, and she's done a lot of work on this question about what's the connection between language and thought. And so she uses, I was referring earlier to MRI, FMRI, that's her primary method. And so, she has

• 1:27:42Speaker 01

  been really fascinated by this question about whether, what language is, okay? And so, as I mentioned earlier, you can localize my language area, your language area, in a few minutes, okay? Like 15 minutes, I can listen to language, listen to non-language, or backward speech, or something. And we'll find areas, left lateralized network in my head, which is specially, which is very sensitive to language, as opposed to whatever that control was, okay?

• 1:28:08Lex Fridman?

  Can you specify what you mean by language, like communicated language?

• 1:28:10Speaker 01

  Just sentences. You know, I'm listening to English of any kind, story, or I can read sentences, anything at all that I understand, if I understand it, then it'll activate my language network. So right now, my language network is going like crazy, when I'm talking, and when I'm listening to you, because we're both, we're communicating.

• 1:28:28Lex Fridman?

  And that's pretty stable?

• 1:28:29Speaker 01

  Yeah, it's incredibly stable. So I've, I happen to be married to this woman at Federencio, and so I've been scanned by her over and over and over, since 2007 or '06 or something. And so my language network is exactly the same, you know, like, a month ago, as it was back in 2007. It's amazingly stable, it's astounding. And with it, it's Really fundamentally cool thing. And so my language network is, it's like my face. Okay, it's not changing much over time inside my head.

• 1:28:56Lex Fridman?

  Can I ask a quick question? Sorry, it's a small tangent. At which point in the, as you grow up from baby to adult, does it stabilize?

• 1:29:05Speaker 01

  We don't know. Like, that's, that's a very hard question. They're working on that right now because of the problem scanning little kids, like doing the, trying to do local, trying to do the localization on little children in this scanner, where you're lying in the FMRI scanner. That's the best way to figure out where something's going on inside our brains. And the scanner is loud and you're in this tiny little area, you're claustrophobic. And it doesn't bother me at all. I can go to sleep in there. But some people are bothered by it and little kids don't really like it. And they don't like to lie still. And you have to be really still because you move around, that's, that messes up the coordinates of where, where everything is. And so, you know, try to get, you know, your question is, how and when are language developing? You know, how, when, how does this left lateralized system come to play?

• 1:29:49Speaker 01

  Where's it, you know, and it's really hard to get a two-year-old to do this task. But you can maybe, where they're starting to get three and four and five-year-olds to do this task for short periods. And it looks like it's there pretty early.

• 1:29:59Lex Fridman?

  So clearly, when you lead up to like a baby's first words, before that, there's a lot of fascinating turmoil going on about like figuring out like, what are, what are these people saying?

• 1:30:11Speaker 01

  Yep.

• 1:30:12Lex Fridman?

  And you're trying to like make sense, how does that connect to the world and all that kind of stuff? Yeah, that might be just fascinating development that's happening there. That's hard to interest back. But anyway, you.

• 1:30:22Speaker 01

  Anyway, we're back to the scanner.

• 1:30:23Lex Fridman?

  Yes.

• 1:30:24Speaker 01

  And I can find my network in 15 minutes. And now we can ask, we can ask, find my network, find yours, find, you know, 20 other people do this task.

• 1:30:31Lex Fridman?

  Yep.

• 1:30:32Speaker 01

  And we can do some other tasks. Anything else you think is thinking of some other thing? I can do a spatial memory task. I can do a music perception task. I can do programming task if I program, okay? I can do, where I can like understand computer programs. And none of those tasks tap the language network at all, like at all. There's no overlap. They do, they're, they're highly activated in other parts of the brain. There's a, there's a bilateral network. Which I think she tends to call the multiple demands network, which does anything kind of hard and so anything that's kind of difficult in some ways will activate that multiple demands network. I mean, music will be in some music area, you know, there's music specific kinds

• 1:31:13Speaker 01

  of areas and so, but they're, but, but none of them are activating the language area at all unless there's words. Like, so if you have music and there's a song and you can hear the words, then, then you get the language area.

• 1:31:25Lex Fridman?

  Are we talking about speaking and listening, but are, or are we also talking about reading?

• 1:31:30Speaker 01

  This is all comprehension of any kind. And so.

• 1:31:33Lex Fridman?

  That is fascinating.

• 1:31:34Speaker 01

  So what this, this, this network doesn't make any difference if it's written or spoken. So the, the thing that she calls, Federico calls the, the language network is this high level language. So it's not about the spoken, the spoken language and it's not about the written language. It's about either one of them. And so we're, so when you do speech, you're sort of, you're, you either, you're listening to speech and you, and you subtract away some language you don't understand and so which, or you subtract away back, backward speech, which sounds, sounds like speech, but it isn't. And, and then so you, you take away the sound part altogether. And so, and then if you do written, you get exactly the same network. So for just reading the language versus reading sort of nonsense words or something like that, you'll find exactly the same network. And so this is about high level.

• 1:32:18Lex Fridman?

  The comprehension.

• 1:32:19Speaker 01

  Comprehension of language. Yeah. In this case. And, and the same thing happened. Production's a little harder to run the scanner, but the same thing happens in production. You get the same network. So production's a little harder, right? You have to figure out how do you run a task, you know, in the network such that you're doing some kind of production. And I can't remember what, they've done a bunch of different kinds of tasks there where you get people to, you know, produce things. Yeah. Figure out how to produce. And the same network goes on there, exactly the same place.

• 1:32:41Lex Fridman?

  So if, wait, wait. So if you read random words?

• 1:32:44Speaker 01

  Yeah. If you read things like.

• 1:32:46Lex Fridman?

  Like gibberish?

• 1:32:47Speaker 01

  Yeah, yeah. Lewis Carroll's, 'twas brillig, jabberwacky, right? They call that jabberwacky speech.

• 1:32:53Lex Fridman?

  The network doesn't get activated.

• 1:32:54Speaker 01

  Not as much. There are words in there.

• 1:32:56Lex Fridman?

  Yeah, because it's still.

• 1:32:57Speaker 01

  There's function words and stuff. So it's lower activation.

• 1:33:00Lex Fridman?

  Fascinating.

• 1:33:01Speaker 01

  Yeah, yeah. So there's like, basically the more language like it is, the higher it goes in the language network. And that network is there from when you speak, from as soon as you learn language. And. And it's there, like you speak multiple languages. The same network is going for your multiple languages. So you speak English, you speak Russian, then both of them are hitting that same network. If you're fluent in those languages.

• 1:33:24Lex Fridman?

  So programming.

• 1:33:25Speaker 01

  Not at all. Isn't that amazing? Even if you're a really good programmer, that is not a human language. It's just not conveying the same information. And so it is not in the language network.

• 1:33:35Lex Fridman?

  Is that as mind blowing as I think? That's weird. That's weird.

• 1:33:39Speaker 01

  It's amazing. And so that's like one set of data. This is hers, like shows that what you might think is thinking is not language. Language is just the, just this conventionalized system that we've worked out in human languages. Oh, another fascinating little tidbit is that even if they're these constructed languages like Klingon or, I don't know the languages from Game of Thrones. I'm sorry, I don't remember those languages.

• 1:34:04Lex Fridman?

  There's a lot of people offended right now.

• 1:34:06Speaker 01

  There's people that speak those languages. They really speak those languages because the people that wrote the languages for the shows, they did an amazing job of constructing something like a human language. And those, that, that lights up the language area. That's like, because they can speak, you know, pretty much arbitrary thoughts in a human language. It's not a, it's a constructed human language. And probably it's related to human languages because the people that were constructing them were making them like human languages in various ways. But it also activates the same network, which is pretty, really cool. Anyway.

• 1:34:39Lex Fridman?

  Sorry to go into a place where you may be a little bit philosophical, but is it possible that this area of the brain is doing some kind of translation into a deeper set of, almost like concepts?

• 1:34:53Speaker 01

  It has to be doing. So it's doing in communication, right? It is translating from thought, whatever that is, is more abstract. And it's doing that, that's what it's doing. Like it is, that is kind of what it is doing. It's like kind of a meaning network, I guess.

• 1:35:07Lex Fridman?

  Yeah, like a translation network.

• 1:35:08Speaker 01

  Yeah.

• 1:35:08Lex Fridman?

  But I wonder what is at the core, at the bottom of it? Like what are thoughts? Are they thoughts? To me like.

• 1:35:15Speaker 01

  I don't know.

• 1:35:15Lex Fridman?

  Thoughts and words. Are they neighbors or are, is it one turtle sitting on top of the other? Meaning like, is there a deep? Set of concepts that we

• 1:35:26Speaker 01

  Well, there's connections right between the what these things mean. And then there's probably other, other parts of the brain that what these things mean. And so, you know, when I'm talking about whatever it is I want to talk about, if it's some, it'll be represented somewhere else. That, that knowledge of whatever that is will be represented somewhere else.

• 1:35:42Lex Fridman?

  Well, I wonder if there's like some stable, nicely compressed encoding of meanings.

• 1:35:47Speaker 01

  I don't know.

• 1:35:48Lex Fridman?

  That's separate from language. That like, you know, I guess, I guess the implication here is that,

• 1:35:56Lex Fridman?

  that we don't think in language.

• 1:35:58Speaker 01

  That's correct. Isn't that cool? And, and that's so interesting. So people, I mean, this is like hard to do experiments on, but there is this idea of an inner voice. And a lot of people have an inner voice. And so if you do a poll on the internet and ask if you, you hear yourself talking when you're just thinking or whatever, you know, about 70 or 80% of people will say, yes. Most people have an inner voice. I, I don't. And so I always find this strange when, so when people talk about an inner voice, I always thought this was a metaphor. And they hear, I'm, I know most of you, whoever's listening to this thinks I'm crazy now because I'm, I don't have an inner voice. And I, I just don't know what you're listening to. I, I just, it sounds so kind of annoying to me, but that to have this voice going on while you're, while you're thinking.

• 1:36:42Speaker 01

  But I guess most people have that and I don't have that. And I don't, we don't really know what that, that connects to.

• 1:36:48Lex Fridman?

  I wonder if the inner voice activates that same network. I wonder.

• 1:36:51Speaker 01

  I don't, I don't know. I don't know. But I mean, this can be speechy, right? So that's like the, you hear, do you have an inner voice?

• 1:36:58Lex Fridman?

  I don't think so.

• 1:36:58Speaker 01

  Oh, a lot of people have this sense that they hear other people, they hear themselves. And then say they read someone's email. I've heard people tell me that they hear that other, this other person's voice when they read other people's emails. And I'm like, wow, that sounds so disruptive.

• 1:37:13Lex Fridman?

  I do think I like vocalize what I'm reading, but I don't think I hear a voice.

• 1:37:18Speaker 01

  Well, that's, you probably don't have an inner voice.

• 1:37:20Lex Fridman?

  Yeah, I don't think I have.

• 1:37:20Speaker 01

  People have an inner voice. People have this strong percept of hearing sound in their heads when they're just thinking.

• 1:37:27Lex Fridman?

  I refuse to believe that's the majority of people.

• 1:37:30Speaker 01

  Majority, absolutely.

• 1:37:31Lex Fridman?

  What?

• 1:37:31Speaker 01

  It's, it's like two thirds or three quarters. It's a lot. I would never ask class, they, and I went internet, they always say that. So you're, you're in a minority.

• 1:37:39Lex Fridman?

  It could be a self-report flaw.

• 1:37:41Speaker 01

  It could be.

• 1:37:42Lex Fridman?

  You know, when I'm reading.

• 1:37:43Speaker 01

  Yeah.

• 1:37:45Lex Fridman?

  Inside my head. I'm kind of like saying the words, which is probably the wrong way to read. But I don't hear a voice. There's no percept of a voice. I refuse to believe the majority of people have it. Anyway, it's a fascinating, the human brain is fascinating, but it still blew my mind that the, that language does appear, comprehension does appear to be separate from thinking.

• 1:38:11Speaker 01

  Mm hmm. So that's one set. One set of data from Federencio's group is that no matter what task you do, if it doesn't have words and combinations of words in it, then it won't light up the language network. You know, you could, it'll be active somewhere else, but not there. So that's one. And then this other piece of evidence relevant to that question is that it turns out there are these, this group of people who've had a massive stroke on the left side and wiped out their language network. And as long as they didn't wipe out everything on the right as well, in that case, they wouldn't be, you know, cognitively functionable. But if they just wiped out language, which is pretty tough to do because it's, it's very expansive on the left. But if they have, then there are

• 1:38:54Speaker 01

  these, there's patients like this called so-called global aphasics, who can do any task just fine, but not language. They can't, you can't talk to them. I mean, they don't understand you. They can't speak, can't write, they can't read, but they can do, they can play chess, they can drive their cars, they can do all kinds of other stuff, you know, do math, they can do all, like, so math is not in the language area. For instance, you do arithmetic and stuff, that's not language area. It's got symbols. So people sort of confuse some kind of symbolic processing with language and symbolic processing is not the same. So there are symbols and they have meaning, but it's not language. It's not a, you know, conventionalized language system. And so, so math isn't there. And so they can do math. They're, they do just as well as their control, age match controls and all

• 1:39:38Speaker 01

  these tasks. This is Rosemary Varley over in University College London, who has a bunch of patients who, she's shown this, that they're just, so that sort of combination suggests that language isn't necessary for thinking. It, it doesn't mean you can't think in language. You could think in language because language allows a lot of expression, but it's just, you don't need it for thinking. It's, it suggests that language is separate, is a separate system.

• 1:40:04Lex Fridman?

  This is kind of blowing my mind right now.

• 1:40:05Speaker 01

  It's cool, isn't it?

• 1:40:06Lex Fridman?

  I'm trying to load that in.

• 1:40:07Speaker 01

  Yeah.

• 1:40:07Lex Fridman?

  Because it has implications for. Large language models.

• 1:40:12Speaker 01

  It sure does, and they've been working on that.

• 1:40:15Lex Fridman?

  Well, let's take a stroll there. You wrote that the best current theories of human language are arguably large language models, so this has to do with form.

• 1:40:23Speaker 01

  It's a kind of a big theory, and but the reason it's arguably the best is that it does the best at predicting what's English, for instance. It's incredibly good, you know, it's better than any other theory. It's so, you know, but you know, we don't, you know, there's it's not sort of, there's not enough detail.

• 1:40:41Lex Fridman?

  Well, it's opaque, like there's not, you don't know what's going on.

• 1:40:44Speaker 01

  No, what's going on, it's another black box. But I think it's, you know, it is a theory.

• 1:40:47Lex Fridman?

  What's your definition of a theory? Because it's a gigantic, it's a gigantic black box with, you know, a very large number of parameters controlling it. To me, theory usually requires a simplicity, right?

• 1:41:00Speaker 01

  Well, I don't know, maybe I'm just being loose there. I think it's a, it's not, it's not a great theory, but it's a theory. It's a good theory in one sense in that it covers all the data. Like, anything you want to say in English, it does. And so that's why, that's how it's arguably the best, is that no other theory is as good as a large language model in predicting exactly what's good and what's bad in English. You know, now you're saying, is it a good theory? Well, probably not, you know, because I want a smaller theory than that. It's too big. I agree.

• 1:41:27Lex Fridman?

  You could probably construct mechanism by which it can generate a simple explanation of a particular language, like a set of rules, something like it could generate a dependency grammar for a language, right?

• 1:41:43Speaker 01

  Yes.

• 1:41:43Lex Fridman?

  You could probably, you could probably just ask it about itself.

• 1:41:50Speaker 01

  Well, you know, that's, I mean, that presumes, and there's some evidence for this, that some large language models are implementing something like dependency grammar inside them. And so there's work from a guy called Chris Manning and colleagues over at Stanford in natural language, and they looked at, I don't know how many large language model types, but certainly BERT and some others, where, and where you do some kind of fancy math to figure out exactly what the, sort of what kind of abstractions of representations are going on. And they, and they were saying, it does look like dependency structure is what they're constructing. It doesn't, like, so it's actually a very, very good map. So kind of a, they are constructing something like that.

• 1:42:34Speaker 01

  Does it mean that, you know, that they're using that for meaning? I mean, probably, but we don't know.

• 1:42:40Lex Fridman?

  You write that the kinds of theories of language that LLMs are closest to are called construction-based theories. Can you explain what construction-based theories are?

• 1:42:49Speaker 01

  It's just a general theory of language such that there's a form and a meaning pair for lots of pieces of the language. And so it's primarily usage-based is the construction grammar. It's just, it's trying to deal with the things that people actually say, actually say and actually write. And so that's, it's a usage-based idea. And what's a construction? Well, construction is either a simple word, so of like a morpheme plus its meaning, or a combination of words. It's basically it's combinations of words, like the rules. So, but it's, it's, it's unspecified as to what the form of the grammar is underlyingly.

• 1:43:30Speaker 01

  And so I would, I would argue that the dependency grammar is maybe the right form to use for the types of construction grammar. Construction grammar typically isn't kind of formalized quite. And so maybe the formalization, a formalization of that, it might be in dependency grammar. I mean, I would think so, but I mean, it's up to people, other researchers in that area, if they agree or not, so.

• 1:43:56Lex Fridman?

  Do you think that large language models understand language? Are they mimicking language? I guess the deeper question there is, are they just understanding the surface form? Or do they understand something deeper about the meaning that then generates the form?

• 1:44:13Speaker 01

  I mean, I would argue they're doing the form. They're doing the form, doing it really, really well. And are they doing the meaning? No, probably not. I mean, there's lots of these examples from various groups showing that they can be tricked in all kinds of ways. They really don't understand the, the meaning of what's going on. And so there's a lot of examples that he and other groups have given, which just, which show they don't really understand what's going on. So you know, the Monty Hall problem is this silly problem, right? Where, you know, if you have three door, it's, it's let's make a deal is this old game show. And there's three doors and there's a prize behind one and there's some. Junk prizes behind the other two and you're trying to select one.

• 1:44:54Speaker 01

  And if you, you know, he knows, Monty, he knows where the target item is, the good thing. He knows everything is back there and you're supposed to, he, he gives you a choice. You choose one of the three and then he opens one of the doors and it's some junk prize. And then the question is, should you trade to get the other one? And, and the answer is yes, you should trade because he knew which ones you could turn around. And so now the odds are two thirds. Okay. And then you just change that a little bit to the large language. Large language models have seen that, that, that explanation so many times that it just, if you change the story, it's a little bit, but it make it sound like it's the Monty Hall problem, but it's not, you just say, oh, um, there's three doors and one behind them is a good prize. There's two bad doors. I happen to know it's behind door number one.

• 1:45:39Speaker 01

  The good prize, the car is behind door number one, so I'm going to choose door number one. Monty Hall opens door number three and shows me nothing there. Should I trade for door number two, even though I know the good prize is in door number one? And then, and then the large language model will say, yes, you should trade because it's a, it's, it just goes through the, the, the, the, the forms that it's seen before so many times on these cases where it, yes, you should trade because you know, your odds have shifted from one in three now to two out of three to being that thing. It doesn't have any way to remember that actually you have a hundred percent probability behind that door number one. You know that that's not part of the, of the, the scheme that it's seen hundreds and hundreds of times before. And so it can't, you can't, even if you try to explain to it that it's wrong, that they

• 1:46:21Speaker 01

  can't do that. It'll just keep giving you back the, the, the problem.

• 1:46:25Lex Fridman?

  But it's also possible the large language model will be aware of the fact that there's sometimes over representation of a, of a particular kind of formulation. And it's easy to get tricked by that. And so you could see if they get larger and larger, models be a little bit more skeptical. So you see a over representation. So like you, it just feels like form can. Training on form can go really far in terms of being able to generate things that look like the thing understands deeply the underlying world, world model

• 1:47:07Lex Fridman?

  of the kind of mathematical world, physical world, psychological world that would generate these kinds of sentences. It just feels like you're creeping close to the meaning part. Easily fooled, all this kind of stuff, but that's humans too. So it just seems really impressive how often it seems like it understands concepts.

• 1:47:34Speaker 01

  I mean, you don't have to convince me of that. I'm, I am very, very impressed. But does it, does do, I mean, you're, you're giving a possible world where maybe someone's going to train some other versions such that it'll be somehow abstracting away from types of forms. I mean, I don't think that's happened. And so

• 1:47:52Lex Fridman?

  Well, no, no, no, I'm not saying that. I think when you just look at anecdotal examples and just showing a large number of them where it doesn't seem to understand.

• 1:48:01Speaker 01

  Yeah.

• 1:48:01Lex Fridman?

  And it's easily fooled.

• 1:48:02Speaker 01

  Yes.

• 1:48:03Lex Fridman?

  That does not seem like a scientific, um,

• 1:48:06Speaker 01

  Well,

• 1:48:06Lex Fridman?

  the data-driven like analysis of like, how many places is it damn impressive?

• 1:48:11Speaker 01

  Oh, no.

• 1:48:12Lex Fridman?

  In terms of meaning and understanding and how many places is easily fooled and like

• 1:48:16Speaker 01

  That's not the inference.

• 1:48:17Lex Fridman?

  Yeah.

• 1:48:18Speaker 01

  So I don't want to make that, the inference I don't, I wouldn't want to make was that inference. The inference I'm trying to push is just that, is it, is it like humans here? It's probably not like humans here. It's different. So humans don't make that error. If you explain that to them, they're not going to make that error. You know, they don't make that error. And so that's something, it's doing something different from humans that they're doing in that case.

• 1:48:38Lex Fridman?

  Well, what's the mechanism by which humans figure out that it's an error?

• 1:48:42Speaker 01

  I'm just saying, the error there is like, if I explain to you, there's a hundred percent chance that the car is behind this case, that this door, will you, do you want to trade? People say no, but this thing will say yes, because it's so trick, it's that, that trick, it's so wound up on the form that it's, that's an error that a human doesn't make, which is kind of interesting.

• 1:49:03Lex Fridman?

  Less likely to make, I should say.

• 1:49:04Speaker 01

  Yeah, less likely.

• 1:49:05Lex Fridman?

  Because like humans are very

• 1:49:07Speaker 01

  Oh, yeah.

• 1:49:09Lex Fridman?

  I mean, you're asking, you know, you're asking humans, you're asking a system to understand a hundred percent, like asking some mathematical concepts. And so like,

• 1:49:20Speaker 01

  Look, the places where large language models are, the form is amazing. So let's go back to nested structures, center embedded structures. Okay, if you ask a human to complete those, they can't do it. Neither can a large language model. They're just like humans in that. If you ask, if I ask a large language model-

• 1:49:36Lex Fridman?

  That's fascinating, by the way.

• 1:49:37Speaker 01

  That-

• 1:49:38Lex Fridman?

  The central embedding-

• 1:49:39Speaker 01

  Yeah.

• 1:49:39Lex Fridman?

  The central embedding is, it struggles with-

• 1:49:41Speaker 01

  Just like humans, exactly like humans. Exactly the same way as humans. They get, and that's not trained. So they do exactly, so that is a similarity. So, but then it's, it's, that's not meaning, right? This is form. But when we get into meaning, this is where they get kind of messed up. Where you start to saying, oh, what's behind this door? Oh, it's, you know, this is the thing I want. Humans don't mess that up as much, you know? Here, they, the form is, it's just like, the form of the match is amazing, is similar, without being trained to do that. I mean, it's trained in the sense that it's getting lots of data, which is just like human data, but it's not being trained on, uh, you know, bad sentences and being told what's bad. It just can't do those.

• 1:50:22Speaker 01

  It'll actually say things like, those are too hard for me to complete, or something, which is kind of interesting, actually, kind of, how does it know that? I don't know.

• 1:50:30Lex Fridman?

  But it really often doesn't just complete, they get off, very often says stuff that's true. And sometimes says stuff that's not true. And almost always the form is great.

• 1:50:45Speaker 01

  Yeah.

• 1:50:45Lex Fridman?

  But it's still very surprising that with really great form, it's able to generate a lot of things that are true. Based on what it's trained on and so on.

• 1:50:56Speaker 01

  Yes, yes, yes.

• 1:50:56Lex Fridman?

  So it's not just, it's not just form that is generating. It's mimicking true statements-

• 1:51:04Speaker 01

  That's right, that's right.

• 1:51:05Lex Fridman?

  From the internet. I guess, I guess the underlying idea there is that on the internet, truth is overrepresented-

• 1:51:11Speaker 01

  Yeah.

• 1:51:12Lex Fridman?

  -versus falsehoods.

• 1:51:13Speaker 01

  I think that's probably right. Yeah.

• 1:51:14Lex Fridman?

  So, but the fundamental thing it's trained on, you're saying, is just form. It's-

• 1:51:19Speaker 01

  I think so. Yeah, yeah, I think so.

• 1:51:21Lex Fridman?

  Uh, well, that's a sad, if that's, to me, that's still a little bit of an open question. I probably lean agreeing with you. Especially now you've just blown my mind that there's a separate module in the brain for language versus thinking.

• 1:51:38Lex Fridman?

  Maybe there's a fundamental part missing from the large language model approach that lacks the thinking, the reasoning capability.

• 1:51:48Speaker 01

  Yeah, that's what this group argues. So the same group, Federencos group, has a recent paper arguing exactly that. There's a guy called Kyle Mahwell, who's here in Austin, Texas, actually. He's an old student of mine, but he's a faculty in linguistics at Texas, and he was the first author on that.

• 1:52:07Lex Fridman?

  That's fascinating. Still, to me, an open question.

• 1:52:10Speaker 01

  Yeah.

• 1:52:11Lex Fridman?

  What are the interesting limits of LLMs?

• 1:52:13Speaker 01

  You know, I don't see any limits to their form. Their form is

• 1:52:18Lex Fridman?

  Impressive.

• 1:52:19Speaker 01

  Yeah, yeah, yeah. It's pretty much, I mean, it's close to

• 1:52:21Lex Fridman?

  Well, you said ability to complete central embeddings.

• 1:52:24Speaker 01

  Yeah, it's just the same as humans. It seems the same.

• 1:52:27Lex Fridman?

  But that's not perfect, right?

• 1:52:28Speaker 01

  That's good. No, but I want to be like humans. I'm trying to, I want a model of humans.

• 1:52:34Lex Fridman?

  Oh, wait, wait, wait. Oh, so perfect is as close to humans as possible. I got it.

• 1:52:39Speaker 01

  Yeah.

• 1:52:39Lex Fridman?

  But you should be able to, if you're not human, you're like, you're superhuman. You should be able to complete central embedded sentences, right?

• 1:52:46Speaker 01

  I mean, that's the mechanism is if it's modeling some, I think it's kind of really interesting that it can't.

• 1:52:53Lex Fridman?

  That's really interesting.

• 1:52:54Speaker 01

  That it's more like, like, I think it's potentially underlyingly modeling something like what the way the form is processed.

• 1:53:01Lex Fridman?

  The form of human language.

• 1:53:02Speaker 01

  The way that

• 1:53:03Lex Fridman?

  And how humans process the language.

• 1:53:05Speaker 01

  Yes. I think that's plausible.

• 1:53:07Lex Fridman?

  And how they generate language, process language and generate language. That's fascinating. So in that sense, they're perfect. If we can just linger on the center embedding thing that's hard for LLMs to produce, and that seems really impressive because that's hard for humans to produce. And how does that connect to the thing we've been talking about before, which is the dependency grammar framework in which you view language and the finding that short dependencies seem to be a universal part of language. So why is it hard to complete center embeddings?

• 1:53:41Speaker 01

  So what I like about dependency grammar is it makes

• 1:53:47Speaker 01

  The cognitive cost associated with longer distance connections, very transparent. Basically, there's some, it turns out, there is a cost associated with producing and comprehending connections between words which are just not beside each other. The further apart they are, the worse it is, according to, well, we can measure that. And there is a cost associated with that.

• 1:54:10Lex Fridman?

  Can you just linger on, what do you mean by cognitive cost?

• 1:54:13Speaker 01

  Sure.

• 1:54:14Lex Fridman?

  And how do you measure?

• 1:54:14Speaker 01

  Oh, well, you can measure it in a lot of ways. The simplest is just asking people to say whether, you know, how good a sentence sounds. We just ask, that's one way to measure. And you try to triangulate then across sentences and across structures to try to figure out what the source of that is. You can look at reading times in controlled materials, you know, and certain kinds of materials, and then we can like measure the dependency distances there. We can, there's a recent study which looked at, we're talking about the brain here, we could look at the language network, okay? We could look at the language network and we could look at the activation in the language network and how big the activation is depending on the length of the dependencies.

• 1:54:58Speaker 01

  And it turns out, in just random sentences that you're listening to, if you're listening to, so it turns out there are people listening to stories here, and the bigger, the longer the dependency is, the stronger the activation in the language network. And so there's some measure, there's a different, there's a bunch of different measures we could do, that's a kind of a neat measure, actually, of actual

• 1:55:20Lex Fridman?

  Activations.

• 1:55:20Speaker 01

  Activation in the brain.

• 1:55:21Lex Fridman?

  So that you can somehow, in different ways, convert it to a number. I wonder if there's a beautiful equation connecting cognitive cost and length of dependency? E equals mc squared, kind of thing?

• 1:55:30Speaker 01

  Yeah, it's complicated, but probably it's doable. I would, I would guess it's doable. I tried to do that a while ago, and I was reasonably successful, but for some reason, I stopped working on that. I do, I agree with you, that it would be nice to figure out. So there's like some way to figure out the cost. I mean, it's complicated. Another issue you raised before was, like, how do you measure distance? Is it words? It probably isn't, is the part of the problem, is that some words matter more than others, and probably, you know, Meaning like nouns might matter depending and then it maybe depends on which kind of noun. Is it a noun we've already introduced or a noun that's already been mentioned? Is it a pronoun versus a name? Like, like all these things probably matter. So probably the simplest thing to do is just like, oh, let's forget about all that.

• 1:56:15Speaker 01

  And just think about words or morphemes.

• 1:56:18Lex Fridman?

  For sure, but there might be like, there might be some insight in the kind of function.

• 1:56:24Speaker 01

  Yeah, yeah.

• 1:56:25Lex Fridman?

  That fits the data, meaning like quadratic, like what?

• 1:56:30Speaker 01

  I think it's an exponential. So we think it's probably an exponential such that the longer the distance, the less it matters. And so then, then it's the sum of those is my, that, that was our best guess a while ago. So that you've got a bunch of dependencies. If you've got a bunch of them that are being connected at some point, that's like at, at the ends of those, the, the cost is the, is some exponential function of those is my guess. But because the, the reason it's probably an exponential is like, it's, it's not just the distance between two words. Cause I can make a very, very long subject verb dependency by adding lots and lots of noun phrases and prepositional phrases. And it doesn't matter too much. It's when you do nested, when I have multiple of these, then, then things get, go really bad, go south.

• 1:57:14Lex Fridman?

  Probably somehow connected to working memory.

• 1:57:16Speaker 01

  Yeah, yeah, that's probably the function of the memory here is, is the access is trying to find those earlier things. It's kind of hard to figure out what was referred to earlier. Those are those connections. That's, that's the sort of notion of murky, as opposed to a storagey thing, but trying to connect, retrieve, retrieve those earlier words, depending on what was in between. And then, then we're talking about interference of similar things in between. That's the right theory probably has that kind of notion in it is interference of similar. And so I'm, I'm dealing with abstraction over the right theory, which is just, you know, it's count words. It's not right, but it's close. And then maybe you're right though, there's some sort of an exponential or something on, on the, to figure out the total.

• 1:57:58Speaker 01

  So we can figure out a function for any given, for every, any given sentence in any given language. But you know, it's funny, you know, people haven't done that too much, which I do think is. I'm interested that you find that interesting. I really find that interesting. And a lot of people haven't found it interesting. And I don't know why I haven't got people to want to work on that. I really like that, too.

• 1:58:16Lex Fridman?

  No, that's a, that's a beautiful idea. And the underlying idea is beautiful, that there's a cognitive cost that correlates with the length of dependency. It just, it feels like it's a deep, I mean, language is so fundamental to the human experience. And this is a nice, clean theory of language where

• 1:58:33Speaker 01

  Yeah.

• 1:58:34Lex Fridman?

  it's like, wow, okay. So like, we like our words close together.

• 1:58:38Speaker 01

  Yeah.

• 1:58:38Lex Fridman?

  Depend on words close together.

• 1:58:40Speaker 01

  Yeah, that's why I like it, too. It's so simple.

• 1:58:42Lex Fridman?

  Yeah, the simplicity of the theories, man.

• 1:58:44Speaker 01

  And yet it explains some very complicated phenomena. If you, if I write these very complicated sentences, it's kind of hard to know why they're so hard. And you can like, oh, nail it down. I can do, like, I give you a math formula for why each one of them is bad and where. And that's kind of cool. I think that's very neat.

• 1:59:00Lex Fridman?

  Have you gone through the process? Is there like, you take a piece of text and then simplify? Sort of like, there's an average length of dependency. And then you like, you know, reduce it and see comprehension on the entire, not just a single sentence, but like, you know, you go from James Joyce to Hemingway or something.

• 1:59:21Speaker 01

  No, no, a simple answer is no, that does, there's probably things you can do in that, in that kind of direction.

• 1:59:27Lex Fridman?

  That's fun.

• 1:59:27Speaker 01

  We might, you know, we, we're going to talk about legalese at some point. And so we, maybe we'll talk about that kind of thinking with, with applied to legalese.

• 1:59:35Lex Fridman?

  Well, let's talk about legalese, because you mentioned that as an exception. We're just taking tangent upon tangent. That's an interesting one. You're giving it as an exception.

• 1:59:42Speaker 01

  It's an exception.

• 1:59:44Lex Fridman?

  That you say that most natural languages, as we've been talking about, have local dependencies with one exception, legalese.

• 1:59:52Speaker 01

  That's right.

• 1:59:53Lex Fridman?

  So what is legalese, first of all?

• 1:59:55Speaker 01

  Oh, well, legalese is what you think it is. It's just any legal language.

• 2:00:00Lex Fridman?

  I mean, like, I actually know very little about the kind of language the lawyers use.

• 2:00:04Speaker 01

  So I'm just thinking about language in laws and language in contracts.

• 2:00:08Lex Fridman?

  Got it.

• 2:00:08Speaker 01

  So the stuff that you have to run into, we have to run into every other day, every day. And you skip over because it reads poorly and or, you know, partly it's just long, right? There's a lot of text there that we don't really want to know about. And so, but the, the thing I'm interested in, so I, I've been working with this guy called Eric Martinez, who is a, he was a lawyer who was taking my class. I was teaching a psycholinguistics lab class and I have been teaching it for a long time at MIT. And he's a, he was a law student at Harvard and he took the class because he had done some linguistics as an undergrad and he was interested in the problem of why legalese sounds hard to understand. You know, why, and so why is it hard to understand?

• 2:00:51Speaker 01

  And why do they write that way if it is so hard to understand? It seems apparent that it's hard to understand. The question is, why is it? And so we, we didn't know. And we did an evaluation of a bunch of contracts. Actually, we just took a bunch of sort of random contracts. Cause I don't know, you know, there's contracts and laws might not be exactly the same, but contracts are kind of the things that most people have to deal with most of the time. And so that's kind of the most common thing that humans have, like humans, that, that adults in our industrialized society have to deal with a lot. And so, so that's what we, we pulled and we, we didn't know what was hard about them. But it turns out that the way they're written is, is very center embedded, has nested structures in them. So it has low frequency words as well.

• 2:01:36Speaker 01

  That's not surprising. Lots of texts have low, it does have surprising, slightly lower frequency words than other kinds of control texts, even sort of academic texts. Legal leaves is even worse. It is the worst that, that we were being assigned.

• 2:01:49Lex Fridman?

  You just, you just reveal the game that lawyers are playing.

• 2:01:53Speaker 01

  They're not though.

• 2:01:53Lex Fridman?

  They're optimizing a different, well.

• 2:01:55Speaker 01

  You know, it's interesting. That's a, that's a, now you're getting at why. And so, and I don't think, so now you're saying it's, they're doing it intentionally. I don't think they're doing it intentionally, but let's, let's, um, let's.

• 2:02:03Lex Fridman?

  It's an emergent phenomenon.

• 2:02:04Speaker 01

  Yeah, yeah, yeah. We'll get to that. We'll get to that. And so, but, but we wanted to see why, so we see what first as opposed to, so like, cause, cause it turns out that we're not the first to observe that legalese is weird. Like back to Nixon had a Plain Language Act in 1970 and Obama had one. And boy, a lot of these, you know, a lot of presidents have said, oh, we've got to simplify legal language, must simplify it. But if you don't know how it's complicated, it's not easy to simplify it. You need to know what it is you're supposed to do before you can fix it. Right? And so you need to like, you need a psycholinguist to analyze the text and see what's wrong with it before you can like fix it. You don't know how to fix it. How am I supposed to fix something? I don't know what's wrong with it. And so what we did was just, that's what we did. We figured out, well, that's okay.

• 2:02:48Speaker 01

  We just took a bunch of contracts, had people, and we encoded them for the, it's a bunch of features. And so another feature that people, one of them was the center embedding. And so that is like basically how often a clause would intervene between a subject and a verb. For example, that's one kind of a center embedding of a clause. Okay. And turns out they're massively center embedded. Like, so I think in random contracts and in random laws, I think you get about 70% or 80, something like 70% of sentences have a center embedded clause in them, which is insanely high. If you go to any other text, it's down to 20% or something. It's, it's so much higher than the, any control you can think of, including, you think, oh,

• 2:03:31Speaker 01

  people think, oh, technical academic texts. No, people don't write center embedded sentences in, in technical academic texts. I mean, they do a little bit, but much, it's on the 20%, 30% realm as opposed to 70. And so, and so there's that. And, and there's low frequency words. And then people, oh, maybe it's passive. People don't like the passive. Passives, for some reason, the passive voice in English has a bad rap, and I'm not really sure where that comes from. And, and there is a lot of passive in the, there's much more passive voice in, in the, in legalese than there is in other texts.

• 2:04:03Lex Fridman?

  The passive voice accounts for some of the low frequency words.

• 2:04:05Speaker 01

  No, no, no, no, those are separate. Those are separate.

• 2:04:08Lex Fridman?

  Oh, so passive voice sucks. Low frequency word sucks.

• 2:04:10Speaker 01

  Well, sucks is different. So these are different.

• 2:04:12Lex Fridman?

  It's a judgment on passive.

• 2:04:13Speaker 01

  Yeah, yeah, yeah. Pass, drop the judgment. It's just like, these are frequent, these are things which happen in legalese texts. Then we can ask, the dependent measure is like, how well you understand those things with those features. Okay? And so then, and it turns out the passive makes no difference. So it has a zero effect on your comprehension ability, on your recall ability, no, nothing at all. That makes no effect. The words matter a little bit. They do. Low-frequency words are going to hurt you in recall and understanding. But what really hurts is the center embedding. That kills you. That slows people down. That makes them very poor at understanding. That makes them, they can't recall what was said as well, nearly as well. And we did this not only on laypeople. We did it on a lot of laypeople. We ran it on 100 lawyers.

• 2:04:57Speaker 01

  We recruited lawyers from a wide range of different levels of law firms and stuff. And they have the same pattern. So they also, like, when they did this, I did not know what happened. I thought, maybe they could process, they're used to legalese. They can process it just as well as if it was normal. No, no. They, they're much better than laypeople. So they're much, they can much better recall, much better understanding. But they have the same main effects as laypeople, exactly the same. So they also much prefer the non-center. So we constructed non-center embedded versions of each of these. We constructed versions which have higher-frequency words in those places.

• 2:05:39Speaker 01

  And we did, we un-passivized, we turned them into active versions. The passive-active made no difference. The words made little difference. And un-center embedding makes big differences in all the populations.

• 2:05:52Lex Fridman?

  Un-center embedding. How hard is that process, by the way?

• 2:05:54Speaker 01

  Not very hard.

• 2:05:55Lex Fridman?

  Don't question, but how hard is it to detect center embedding?

• 2:05:59Speaker 01

  Oh, easy, easy to detect.

• 2:06:00Lex Fridman?

  You're just looking at long dependencies? Or is there a real?

• 2:06:02Speaker 01

  You can, so there's automatic parsers for English, which are pretty good.

• 2:06:06Lex Fridman?

  And they can detect center embedding?

• 2:06:07Speaker 01

  Oh, yeah.

• 2:06:08Lex Fridman?

  Or, I guess, nesting?

• 2:06:10Speaker 01

  Perfectly. Yeah, pretty much.

• 2:06:12Lex Fridman?

  So you're not just looking for long dependencies. You're just literally looking for center embedding?

• 2:06:16Speaker 01

  Yeah, we are in this case, in these cases. But long dependencies, they're highly correlated, these things.

• 2:06:20Lex Fridman?

  So like, center embedding is a big bomb you throw inside of a sentence? That just blows up, that makes...

• 2:06:26Speaker 01

  Yeah. Can I read a sentence for you from these things? I mean, this is just like, one of the things that, this is just typical.

• 2:06:32Lex Fridman?

  My eyes might glaze over in mid-sentence.

• 2:06:37Lex Fridman?

  No, I understand that. I mean, legalese is hard.

• 2:06:40Speaker 01

  This is a go. It goes, "In the event that any payment or benefit by the company, all such payments and benefits, including the payments and benefits under Section 3A hereof, being here and after referred to as a total payment, would be subject to the excise tax, then the cash severance payments shall be reduced." So that's something we pulled from a regular text, from a contract.

• 2:06:58Lex Fridman?

  Wow.

• 2:06:59Speaker 01

  And the center embedded bit there is just, for some reason, there's a definition. They throw the definition of what payments and benefits are in between the subject and the verb. Let's, how about don't do that?

• 2:07:11Lex Fridman?

  Yeah.

• 2:07:11Speaker 01

  How about put the definition somewhere else as opposed to in the middle of the sentence? And so that's, that's very, very common, by the way. That's, that's what happens. You just throw your definitions, you use a word, a couple of words, and then you define it, and then you continue the sentence. Like, just don't write like that. And you ask, so then we asked lawyers, we thought, oh, maybe lawyers like this. Lawyers don't like this. They don't like this. They don't want to, they don't want to write like this. They, they, we asked them to rate materials which are with the same meaning, with uncentered and centered, and they much preferred the uncentered versions.

• 2:07:45Lex Fridman?

  On the comprehension, on the reading side.

• 2:07:47Speaker 01

  Yeah, well, and we asked them, we asked them, would you hire someone who writes like this or this? We asked them all kinds of questions, and they always preferred the less complicated version, all of them. So I don't even think they want it this way.

• 2:07:58Lex Fridman?

  Yeah, but how did it happen?

• 2:07:59Speaker 01

  How did it happen? That's a very good question. And the answer is, they still don't know. But...

• 2:08:05Lex Fridman?

  I have some theories.

• 2:08:06Speaker 01

  Well, our, our best theory at the moment is that there's, there's actually some kind of a performative meaning in the center embedding, in the style, which tells you it's legalese. We think that that's the kind of a style which tells you it's legalese. Like, that's a, it's a reasonable guess, and maybe it's just, so, for instance, if you're, like, it's like a magic spell. So we kind of call this the magic spell hypothesis. So when you give them, when you tell someone to put a magic spell on someone, what do you do? You know, people know what a magic spell is and they do a lot of rhyming. You know, that's kind of what people will tend to do. They'll do rhyming and they'll do sort of like some kind of poetry kind of thing.

• 2:08:43Lex Fridman?

  Abracadabra type of thing.

• 2:08:44Speaker 01

  Exactly, yeah. And maybe that's, there's a syntactic sort of reflex here of a magic spell, which is centramenting. And so that's like, oh, it's trying to like, tell you this is like, this is something which is true, which is what the goal of law, law is, right? Is telling you something that we want you to believe is certainly true, right? That's what legal contracts are trying to enforce on you, right? And so maybe that's like a form which has, this is like an abstract, very abstract form, centramenting, which has a, has a, has a meaning associated with it.

• 2:09:16Lex Fridman?

  Well, don't you think there's an incentive?

• 2:09:20Speaker 01

  Yeah.

• 2:09:20Lex Fridman?

  For lawyers to generate things that are hard to understand?

• 2:09:25Speaker 01

  That was our, one of our working hypotheses. We just couldn't find any evidence of that.

• 2:09:28Lex Fridman?

  No, lawyers also don't understand it. But you're creating space, why you, I mean, you ask in a communist Soviet Union, the individual members, their self-report is not going to correctly reflect what is broken about the gigantic bureaucracy that leads to Chernobyl or something like this. I think the incentives under which you operate are not always transparent to the members within that system. So like, it just feels like a strange coincidence that, like, there is benefit if you just zoom out, look at the system as opposed to asking individual lawyers,

• 2:10:09Lex Fridman?

  that making something hard to understand is going to make a lot of people money.

• 2:10:14Speaker 01

  Yeah.

• 2:10:15Lex Fridman?

  Like, there's going to, you're gonna need a lawyer to figure that out, I guess, from the perspective of the individual. But then that could be the performative aspect. It could be as opposed to the incentive driven to be complicated. It could be performative to where we lawyers speak in this sophisticated way and you regular humans don't understand it, so you need to hire a lawyer. Yeah, I don't know which one it is, but it's suspicious. Suspicious that it's hard to understand and that everybody's eyes glaze over and they don't read.

• 2:10:44Speaker 01

  I'm suspicious as well. I'm still suspicious. And I hear what you're saying. It could be kind of, you know, no individual and even average of individuals, it could just be a few bad apples in a way which are driving the effect in some way.

• 2:10:56Lex Fridman?

  Influential bad apples at the sort of, that everybody looks up to, whatever, they're like, is central figures in how, you know.

• 2:11:05Speaker 01

  But it turns, but it is, it is kind of interesting that among our hundred lawyers, they did not share that.

• 2:11:11Lex Fridman?

  They didn't want this. That's fascinating.

• 2:11:12Speaker 01

  They really didn't like it. And so it gave us hope.

• 2:11:15Lex Fridman?

  And they weren't better than regular people at comprehending it. Or they were on average better.

• 2:11:19Speaker 01

  But they had the same difference.

• 2:11:21Lex Fridman?

  The same, same difference.

• 2:11:21Speaker 01

  Exact same difference. So they, but I, they wanted it fixed. So they, they also, and so that, that gave us hope that because it actually isn't very hard to construct a material which is un-center embedded and has the same meaning, it's not very hard to do. Just basically in that situation, you're just putting definitions outside of the subject verb relation in that particular example. And that's kind of, that's pretty general. What they're doing is just throwing stuff in there, which you didn't have to put in there. There's extra words involved typically. You may need a few extra words, sort of to refer to the things that you're defining outside in some way, as a, because if you only use it in that one sentence, then there's no reason to introduce extra, extra terms.

• 2:12:03Speaker 01

  But so we might have a few more words, but it'll be easier to understand. So, I mean, I have hope that now that maybe we can make legalese less, less convoluted in this way.

• 2:12:15Lex Fridman?

  So maybe the, the next president of the United States can, instead of saying generic things, say, I ban center, center embeddings and make Ted the, the language czar of the United States.

• 2:12:27Speaker 01

  Eric Martinez is the guy you should really put in there. Yeah.

• 2:12:30Lex Fridman?

  Yeah. But center embeddings are the, the bad thing to have.

• 2:12:36Speaker 01

  That's right.

• 2:12:36Lex Fridman?

  So you can get rid of that.

• 2:12:38Speaker 01

  That'll do a lot of it. That'd fix a lot.

• 2:12:40Lex Fridman?

  Fascinating. That is so fascinating. And it is really fascinating on many fronts that humans are just not able to deal with this kind of thing. And that language, because of that evolved in the way you did. It's fascinating. So one of the mathematical formulations you have when talking about languages, communication is this idea of noisy channels.

• 2:13:02Lex Fridman?

  What's a noisy channel?

• 2:13:04Speaker 01

  So that's about communication. And so this is going back to Shannon. So Shannon, Claude Shannon was a student at MIT in the 40s. And so he wrote this very influential piece of work about communication theory or information theory. And he was interested in human language, actually. He was trying, he was interested in this problem of communication, of getting a message from my head to your head. And so, and he was concerned or interested in what was a robust way to do that. And so that, assuming we both speak the same language, we both already speak English, whatever, you know, whatever the language is, we speak that.

• 2:13:46Speaker 01

  What is a way that I can say the language so that it's most likely to get the signal that I want to you? And so, and then the problem there in the communication is the noisy channel, is that there's, I make, there's a lot of noise in the system. I don't speak perfectly. I make errors. That's noise. There's background noise. You know, you know that.

• 2:14:09Lex Fridman?

  Like a literal.

• 2:14:10Speaker 01

  Literal background noise. There is like white noise in the background or some other kind of noise or some speaking going on that you're, or just you're at a party, that's background noise. You're trying to hear someone, it's hard to understand them because there's all this other stuff going on in the background. And, and then there's noise on the communication, on the receiver side. So that you have some problem maybe understanding me for stuff that's just internal to you in some way. So you've got some other problems, whatever, with understanding for whatever reasons. Maybe you're, maybe you've had too much to drink. You know, who knows why you're not able to pay attention to the signal. So that's the noisy channel. And so, so that language, if it's a communication system, we are trying to optimize, in some sense, the passing of the message from one side to the other.

• 2:14:55Speaker 01

  And so it, I mean, one idea is that maybe, you know, aspects of like word order, for example, might have optimized in some way to make language a little more easy to be passed from speaker to listener. And so Shannon's the guy that did this stuff way back in the forties. He, you know, it's very interesting, you know, historically, he was interested in working in linguistics. He was in MIT and he did, this is his master's thesis of all things. You know, it's crazy how much, how much he did for his master's thesis in 1948, I think, or 49, something. And, and he wanted to keep working in language and it just wasn't a popular. Communication as a reason, a source for what language was, wasn't popular at the time. So Chomsky was becoming, was moving in there. He was, and he just wasn't able

• 2:15:40Speaker 01

  to get a handle there, I think. And so, and so he moved to Bell Haps and worked on communication from a mathematical point of view and was, you know, did all kinds of amazing work. And so he's just-

• 2:15:52Lex Fridman?

  More on the signal side versus like the language side?

• 2:15:54Speaker 01

  Yeah.

• 2:15:56Lex Fridman?

  Yeah, it would have been interesting to see if he pursued the language side.

• 2:15:58Speaker 01

  Yeah.

• 2:15:59Lex Fridman?

  That's really interesting.

• 2:15:59Speaker 01

  Yeah, he was interested in that. His examples in the 40s are kind of like, they're very language-like things.

• 2:16:07Lex Fridman?

  Yeah.

• 2:16:08Speaker 01

  We can kind of show that there's a noisy channel process going on in when you're listening to me, you know, you can often sort of guess what I meant by what I, you know, what you think I meant, given what I said. And I, I mean, with respect to sort of why language looks the way it does, we might, there might be sort of, as I alluded to, there might be ways in which word order is somewhat optimized for, for, because of the noisy channel in some way.

• 2:16:33Lex Fridman?

  I mean, that's really cool to sort of model, if you don't hear certain parts of a sentence, or have some probability of missing that part, like, how do you construct a language that's resilient to that, that's somewhat robust to that?

• 2:16:44Speaker 01

  Yeah, that's the idea.

• 2:16:46Lex Fridman?

  And then you're kind of saying like, the word order and the syntax of a language, the dependency length are all helpful.

• 2:16:54Speaker 01

  Yeah. Well, dependency length is really about memory, right? I think that's like about sort of what's easier or harder to produce in some way. And these other ideas are about sort of robustness to communication. So the problem of potential loss of, loss of signal due to noise. It's so that, there's, there may be aspects of word order, which is somewhat optimized for that. And, and, you know, we have this one guess in that direction. And these are kind of just so stories. I have to be, you know, pretty frank. They're not, like, I can't show this is true. All we can do is like, look at the current languages of the world. This is like, we can't sort of see how languages change or anything, because we've got these snapshots of a few, you know, 100 or a few thousand languages. We don't have, we don't really, we can't do the right kinds of modifications to test these things experimentally. And so, you know, so just take that, this with

• 2:17:39Speaker 01

  a grain of salt, okay, from here, this, this stuff. The dependency stuff I can, I'm much more solid on. And like, here's what the lengths are, and here's, and here's what's hard, and here's what's easy. And this is a reasonable structure. I think I'm pretty reasonable. Here's like, why- You know, why does the word order look the way it does is we're now into shaky territory, but it's kind of cool.

• 2:17:57Lex Fridman?

  We're talking about, just to be clear, we're talking about maybe just actually the sounds of communication, like you and I are sitting in a bar, it's very loud.

• 2:18:05Speaker 01

  Yeah.

• 2:18:06Lex Fridman?

  You model with a noisy channel, the loudness, the noise, and we have the signal that's coming across, and you're saying word order might have something to do with optimizing that.

• 2:18:18Speaker 01

  Yes.

• 2:18:18Lex Fridman?

  Presence of noise.

• 2:18:19Speaker 01

  Yes.

• 2:18:20Lex Fridman?

  I mean, it's really interesting. I mean, to me, it's interesting how much you can load into the noisy channel, like how much can you bake in? You said like, you know, cognitive load on the receiver end.

• 2:18:29Speaker 01

  We think that those are, there's three, at least three different kinds of things going on there, and we probably don't want to treat them all as the same.

• 2:18:36Lex Fridman?

  Sure.

• 2:18:36Speaker 01

  And so I think that you, you know, the right model, a better model of a noisy channel would treat, would have three different sources of noise, which, because which are background noise, you know, speaker, speaker inherent noise and listener inherent noise. And those are not, those are all different things.

• 2:18:51Lex Fridman?

  Sure. But then underneath it, there's a million other subsets.

• 2:18:55Speaker 01

  Oh, yeah.

• 2:18:55Lex Fridman?

  Like what?

• 2:18:56Speaker 01

  That's true.

• 2:18:56Lex Fridman?

  On the, on the receiving, I mean, I just mentioned cognitive load on both sides. Then there's like speaking, speech impediments or just everything, worldview, I mean, and the meaning, we start to creep into the meaning realm of like, we have different worldviews.

• 2:19:11Speaker 01

  Well, how about just form still, though, like just, just what language you know? Like, so how well you know the language? And so if it's second language for you versus first language, and, and how, maybe what other languages you know, these are still just form stuff, and that's like potentially very informative. And, and you know, how old you are, these things probably matter, right? So like a child learning a language is, is a, you know, as a noisy representation of English grammar, you know, depending on how old they are. So maybe when they're six, they're perfectly formed, but.

• 2:19:43Lex Fridman?

  You mentioned one of the things is like a way to measure the, a language is learning problems. So like, what's the correlation between everything we've been talking about and how easy it is to learn a language? So is, is a, like. Short dependencies correlated to ability to learn a language? Is there some kind of, or like the dependency grammar? Is there some kind of connection there? How easy it is to learn?

• 2:20:10Speaker 01

  Yeah, well, all the languages in the world's language, none is, right now, we know is any better than any other with respect to sort of optimizing dependency lengths, for example. They're all kind of do it, do it well. They all keep low. It's, so I, I think of every human language as some kind of an opposite, sort of an optimization problem, a complex optimization problem to this communication problem. And so they've, like, they've solved it, you know, they're just sort of noisy solutions to this problem of communication. There's just so many ways you can do this.

• 2:20:40Lex Fridman?

  So they're not optimized for learning, they're probably optimized for communication?

• 2:20:43Speaker 01

  And, and learning, so yes, one of the factors which is, yeah, so learning is messing this up a bit. And so, so for example, if it were just about minimizing dependency lengths, and, and that was all that matters, you know, then we, you know, so then, then we might find grammars which didn't have regularity in their rules. Like, but languages always have regularity in their rules. So, so what I mean by that is that if, if I wanted to say something to you in the, in the optimal way to say it was, it would really matter to me, all that mattered was keeping the dependencies a, as close together as possible. Then I, then I would have a very lax set of free structure or, or dependency rule. I wouldn't have very many of those, I would have very little of that.

• 2:21:23Speaker 01

  And I would just put the words as close, the, the things that refer to the things that are connected right beside each other. But we don't do that. Like, there, like, there are word order rules, right? So they're very, and, and depending on the language, they're more and less strict, right? So you speak Russian, they're less strict than English. English has very rigid word order rules. We order things in a very particular way. And, and so why do we do that? Like, that's probably not about communication, that's probably about learning. I mean, then, then we're talking about learning. It's probably easier to learn regular, regular things, things which are very predictable and easy to. So, so that's, that's probably about learning, is my, is our guess, because that can't be about communication.

• 2:22:00Lex Fridman?

  Can it be just noise? Can it be just the messiness of the development of a language?

• 2:22:06Speaker 01

  Well, if it were just a communication, then we should have languages which have very, very free word order. And we don't have that. We have freer, but not free, like there's always.

• 2:22:15Lex Fridman?

  Well, no, but what I mean by noise is like cultural, like sticky cultural things, like the way, the way you communicate, just there's a stickiness to it, that it's, it's an imperfect, it's a noisy, it's stochastic.

• 2:22:30Speaker 01

  Yeah.

• 2:22:30Lex Fridman?

  The function over which you're optimizing is very noisy.

• 2:22:33Speaker 01

  Yeah.

• 2:22:33Lex Fridman?

  So, because I don't, it feels weird to say that learning is part of the objective function, because some languages are way harder to learn than others, right? Or is that, that's not true?

• 2:22:45Speaker 01

  That's not true.

• 2:22:45Lex Fridman?

  That's interesting.

• 2:22:46Speaker 01

  I mean.

• 2:22:47Lex Fridman?

  I mean, that's the public sort of perception, right?

• 2:22:48Speaker 01

  Yes, that's true for a second language.

• 2:22:51Lex Fridman?

  For a second language.

• 2:22:52Speaker 01

  But that depends on what you started with, right? So, so it really depends on how close that second language is to the first language you've got. And so, yes, it's very, very hard to learn Arabic if you've started with English, or it's harder to, you know, harder to learn Japanese, or if you've started with, Chinese, I think, is the worst. In the, there's like Defense Language Institute in the, in the United States, has like a list of how hard it is to learn what language from English. I think Chinese is the worst.

• 2:23:18Lex Fridman?

  But that's the second language. You're saying babies don't care?

• 2:23:21Speaker 01

  No, there's no evidence that there's anything harder, easier, but any baby, any language learned, like by three or four, they speak that language. And so, there's no evidence of any, anything harder, easier about any human language. They're all kind of equal.

• 2:23:34Lex Fridman?

  To what degree is language, this is returning to Chomsky a little bit, is innate? You said that for Chomsky, he used the idea that languages, some aspects of language are innate to explain away certain things that are observed. How much are we born with language at the core of our mind, brain?

• 2:23:56Speaker 01

  I mean, I, you know, the answer is I don't know, of course. But the, I mean, I like to, I'm an engineer at heart, I guess. And I sort of think it's fine to postulate that a lot of it's learned. And so I'm guessing that a lot of it's learned. So I think the reason Chomsky went with innateness is because he hypothesized movement in his grammar. He was interested in grammar and movement's hard to learn. I think he's right. Movement is a harder, it's a hard thing to learn, to learn these two things together and how they interact. And there's like a lot of ways in which you might generate exactly the same sentences. And it's like really hard. And so he's like, oh, I guess it's learned. So I guess it's not learned, it's innate. And if you just throw out the movement and just think about that in a different way,

• 2:24:41Speaker 01

  you know, then you get some messiness. But the messiness is human language, which it actually fits better. It's, that messiness isn't a problem. It's actually, it's a valuable asset of the theory. And so, so I think, I don't really see a reason to postulate much innate structure. And that's kind of why I think these large language models are learning so well, is because I think you can learn the form, the forms of human language from the input. I think that's like, it's likely to be true.

• 2:25:14Lex Fridman?

  So that part of the brain that lights up when you're doing all the comprehension, that could be learned, that could be just, you don't need, you don't need any-

• 2:25:20Speaker 01

  Yeah, it doesn't have to be innate. So like lots of stuff is modular in the brain that's learned. It doesn't have to, you know, so there's something called the visual word form area in the back. And so it's in the back of your head, near the, you know, the visual cortex. Okay. And that is very specialized language, sorry, very specialized brain area, which does visual word processing if you read, if you're a reader. Okay. If you don't read, you don't have it. Okay. Guess what? You spend some time learning to read and you develop that, that brain area which does exactly that. And so these, the modularization is not evidence for innateness. So the modularization of a language area doesn't mean we're born with it. We could have easily learned that. I, we might have been born with it.

• 2:26:04Speaker 01

  I, we just don't know at this point. We might very well have been born with this left lateralized area. I mean, there's like a lot of other interesting components here, features of this kind of argument. So some people get a stroke or something goes really wrong on the left side, where the left, where the language area would be. And that, and that isn't there. It's not, not available. And it develops just fine on the right. So it's no, so it's not about the left. It, it goes to the left. Like, this is a very interesting question. It's like, why is the, why are any of the brain areas the way that they are? And how, how, how did they come to be that way? And, uh, you know, there's these natural experiments which happen where people get these, you know, strange events

• 2:26:46Speaker 01

  in their brains at very young ages, which wipe out sections of their brain. And, and they behave totally normally and no one knows anything was wrong. And we find out later because they happened to be accidentally scanned for some reason. It's like, what, what happened to your left hemisphere? It's missing. There's not many people who've missed their whole left hemisphere, but they'll be missing some other section of their left or their right. And they behave absolutely normally, would never know. So that's like a very interesting, you know, current research. You know, this is another project that this person, F. Federenko is working on. She's got all these people contacting her because she's scanned some people who have been missing sections. One person missing, missed a section of her brain and was scanned in her lab. And she, and she happened to be a writer for

• 2:27:29Speaker 01

  the New York Times. And there was an article in New York Times about, about, uh, the, uh, just about the scanning procedure and, and about what might be learned about by sort of the general process of MRI and language, and not necessarily language. And, and because she's writing for the New York Times, and all these people started writing to her, who also have similar, similar kinds of deficits because they'd been, you know, accidentally, you know, scanned for some reason and, uh, and found out they're missing some section. They, they volunteer to be scanned.

• 2:28:02Lex Fridman?

  These are natural experiments.

• 2:28:03Speaker 01

  Natural experiments. They're kind of messy, but natural experiments. Kind of cool.

• 2:28:06Lex Fridman?

  The, the.

• 2:28:07Speaker 01

  She calls them interesting brains.

• 2:28:09Lex Fridman?

  The first few hours, days, months of human life are fascinating. Cause like, uh, well, inside the womb, actually, like that development.

• 2:28:19Lex Fridman?

  That machinery, whatever that is, seems to create powerful humans that are able to speak, comprehend, think, all that kind of stuff, no matter what happens, not no matter what, but robust to the different ways that the the the brain might be damaged and so on. That's really, that's really interesting. But what would Chomsky say about the fact, the thing you're saying now that languages is, seems to be happening separate from thought? Because as far as I understand, maybe you can correct me, he thought that language underpins.

• 2:28:52Speaker 01

  Yeah, he thinks so. I don't know what he'd say.

• 2:28:55Lex Fridman?

  He would be surprised because for him, the idea is that language is the sort of the foundation of thought.

• 2:29:00Speaker 01

  That's right. Absolutely.

• 2:29:02Lex Fridman?

  And it's pretty mind blowing to think that it could be completely separate from thought.

• 2:29:08Speaker 01

  That's right. But so, you know, he's basically a philosopher, philosopher of language in a way, thinking about these things. It's a fine thought. You can't test it in his methods. You can't do a thought experiment to figure that out. You need a scanner, you need brain damaged people, you need something, you need ways to to measure that. And that's what, you know, FMRI offers as a, and, you know, patients are a little messier. FMRI is pretty unambiguous, I'd say. It's like very unambiguous. There's no way to say that the language network is doing any of these tasks. There's like, you should look at those data. It's like, there's no chance that you can say that the there, those networks are overlapping. They're not overlapping. They're just like completely different.

• 2:29:51Speaker 01

  And so, you know, so the, you know, you can always make, you know, it's only two people, it's four people or something for the, for the patients. And there's something special about them. We don't know. But these are just random people and, and with lots of them, and you find always the same effects and it's very robust, I'd say.

• 2:30:08Lex Fridman?

  What's a fascinating effect?

• 2:30:10Speaker 01

  Yeah.

• 2:30:11Lex Fridman?

  What's the, you mentioned Bolivia. What's the connection between culture and language?

• 2:30:19Lex Fridman?

  You've also mentioned that much of our study of language comes from WEIRD, weird people, western educated, industrialized, rich and democratic. So when you study like remote cultures such as around the Amazon jungle, what can you learn about language?

• 2:30:41Speaker 01

  So that term weird is from Joe Henrich. He's at Harvard. He's a Harvard evolutionary biologist. And so he works on lots of different topics. And he basically was pushing that observation that we should be careful about the inferences we want to make when we're talking in psychology or, yeah, mostly in psychology, I guess, about humans if we're talking about undergrads at MIT and Harvard. Those aren't the same, right? These aren't the same things. And so if you want to make inferences about language, for instance, there's a lot of other kinds of languages in the world than English and French and Chinese.

• 2:31:25Speaker 01

  And so maybe for language, we care about how culture, because cultures can be very, I mean, of course, English and Chinese cultures are very different, but hunter-gatherers are much more different in some ways. And so if culture has an effect on what language is, then we kind of want to look there as well as looking. It's not like the industrialized cultures aren't interesting, of course they are, but we want to look at non-industrialized cultures as well. And so I've worked with two. I've worked with the Chimani, which are in Bolivia and the Amazon, both in the Amazon in these cases. And there are so-called farmer-foragers, which is not hunter-gatherers. It's sort of one-up from hunter-gatherers in that they do a little bit of farming as

• 2:32:09Speaker 01

  well, a lot of hunting as well, but a little bit of farming. And the kind of farming they do is the kind of farming that I might do if I ever were to grow like tomatoes or something in my backyard. It's not like, so it's not like big field farming. It's just farming for a family, a few things you do that. So that's the kind of farming they do. And the other group I've worked with are the Pirahã, which are in also in the Amazon and happen to be in Brazil. And that's with a guy called Dan Everett, who was a linguist anthropologist who actually lived and worked in the, I mean, he was a missionary, actually, initially, back in the seventies, working with, trying to translate languages so they could teach them the Bible, teach them Christianity.

• 2:32:54Lex Fridman?

  What can you say about that?

• 2:32:56Speaker 01

  Yeah, so the two groups I've worked with, the Chimani and the Pirahã, are both isolate languages, meaning there's no known connected languages at all, like just like on their own. Yeah, there's a lot of those and and most of the isolates occur in in the in the Amazon or in Papua New Guinea. And these these places where the world has sort of stayed still for a long enough. And they're like, so there there aren't earthquakes, there aren't.

• 2:33:28Speaker 01

  Well, certainly no earthquakes in the Amazon jungle and and the climate isn't bad, so you don't have droughts. And so, you know, in Africa, you've got a lot of moving of people because there's drought problems. And so, so they get a lot of language contact when you have, when people have to, if you've got to move because you've got no water, then you've got to get going and then then you run into contact with other other tribes, other groups. In the Amazon, that's not the case. And so people can stay there for hundreds and hundreds and probably thousands of years, I guess. And so these groups have, the Chimani and the Pirahã are both isolates in that. And they can just, I guess they've just lived there for ages and ages with minimal contact with other outside groups.

• 2:34:12Speaker 01

  And so, I mean, I'm interested in them because they are, I mean, I, you know, in these cases, I'm interested in their words. I would love to study their syntax, their orders of words, but I'm mostly just interested in how languages, you know, are connected to. Their cultures in this way. And so with the Pirahua, sort of most interesting, I was working on number there, number information. And so the basic idea is, I think language is invented. That's what I get from the words here is that I think language is invented. We talked about color earlier. It's the same idea. So that what you need to talk about with someone else is what you're going to invent words for.

• 2:34:48Lex Fridman?

  Okay.

• 2:34:49Speaker 01

  And so we invent labels for colors that I need, not that I can see, but that things I need to tell you about so that I can get objects from you or get you to give me the right objects. And I just don't need a word for teal or a word for aquamarine in the Amazon jungle for the most part, because I don't have two things which differ on those colors. I just don't have that. And so numbers are really another fascinating source of information here where you might, naively, I certainly thought that all humans would have words for exact counting. And the Pirahua don't. Okay. So they don't have any words for even one. There's not a word for one in their, in their language.

• 2:35:34Speaker 01

  And so there's certainly not a word for two, three, or four. So that kind of blows people's minds off.

• 2:35:39Lex Fridman?

  Yeah, that's blowing my mind.

• 2:35:40Speaker 01

  That's pretty weird.

• 2:35:41Lex Fridman?

  How are you, how are you going to ask, I want two of those?

• 2:35:43Speaker 01

  You just don't. And so that's just not a thing you can possibly ask in the Pirahua. It's not possible. That is, there's no word for that. So here's how we found this out. Okay. So, so it was thought to be a one, too many language. There are three words for quantifiers for, for sets. But, and people had thought that those meant one, two, and many. But what they really mean is few, some, and many. Many is correct. It's few, some, and many. And so, and so the way we figured this out, and this is kind of cool, is that we gave people, we had a set of objects. Okay. These were having to be spools of thread. Doesn't really matter what they are, identical objects. And, and when I sort of start off here, I just give, you know, give you one of those and say, what's that? Okay.

• 2:36:27Speaker 01

  So you're a Pirahua speaker and you tell me what it is. And then I give you two and say, what's that? And, and nothing's changing in this set except for the number. Okay. And then I just ask you to label these things. We just do this for a bunch of different people. And frankly, it's a, I did this task.

• 2:36:40Lex Fridman?

  This is fascinating.

• 2:36:41Speaker 01

  And it's a weird, it's a little bit weird. So they say the word that they thought, that we thought was one, it's few, but for the first one. And then maybe they say few, or maybe they say some for the second. And then for the third or the fourth, they start using the word many for the set. And then Five, six, seven, eight. I go all the way to 10. And it's always the same word. And they look at me like I'm stupid because they told me what the word was for six, seven, eight. And I'm going to continue asking them at nine and 10. I'm like, I'm sorry, I just, I just, they understand that I want to know their language. That's the point of the task is like I'm trying to learn their language. And so that's okay. But it does seem like I'm a little slow because I, they already told me what the word for many was, five, six, seven, and I keep asking. So it's a little funny to do this task over

• 2:37:25Speaker 01

  and over. We did this with a guy called, Dan was the, our translator. He's the only one who really speaks Pirahua fluently. He's a good bilingual for a bunch of languages, but also in English and Pirahua. And then a guy called Mike Frank was also a student with me down there. He and I did these things. And so you do that. Okay. And everyone does the same thing. All, you know, we asked like 10 people and they all do exactly the same labeling for one up. And then we just do the same thing down on like random order. Actually, we do some of them up, some of them down first. Okay. And so we do, instead of one to 10, we do 10 down to one. And so, so I give them 10, nine, and eight, they start saying the word for some. And then at down, when you get to four, everyone is

• 2:38:09Speaker 01

  saying the word for few, which we thought was one. So it's like, it's, the context determined what word, what, what that quantifier they used was. So it's not a count word. They're not, they're not count words. They're, they're just approximate words.

• 2:38:21Lex Fridman?

  And they're going to be noisy when you interview a bunch of people, the, what the definition of few, and there's going to be a threshold in the context.

• 2:38:27Speaker 01

  Yeah. Yeah. I don't know what that means. That's, that's going to be dependent on the context. I think that's true in English too, right? If you ask an English person what a few is, I mean, that's dependent completely on the context.

• 2:38:36Lex Fridman?

  And it might actually be at first hard to discover.

• 2:38:38Speaker 01

  Yeah.

• 2:38:39Lex Fridman?

  Because for a lot of people, the jump from one to two will be few. Right? So it's a jump.

• 2:38:44Speaker 01

  Yeah, it might be. It might still be there. Yeah.

• 2:38:46Lex Fridman?

  Like, it's, I mean, that's fascinating. That's fascinating that numbers don't present themselves.

• 2:38:51Speaker 01

  Yeah. So the words aren't there. And then, and so then we do these other things. Well, if, if they don't have the words. Can they do exact matching kinds of tasks? Can they even do those tasks? And, and, and the answer is sort of yes and no. And so, yes, they can do them. So here's the tasks that we did. We, we put out those spools of thread again. Okay, so maybe I put like three out here. And then, um, that we gave them some objects and those happened to be uninflated red balloons. It doesn't really matter what they are. It's just a bunch of exactly the same thing. And it was easy to put down right next to these, um, um, spools of thread. Okay. And so then I put out three of these and your task was to just put one against each of my three things. And they could do that perfectly. So, I mean, I would actually do that.

• 2:39:35Speaker 01

  It was a very easy task to explain to them because I have, I did this with this guy, Mike Frank. And he would be my, I, I'd be the experimenter telling him to do this and showing him to do this. And then we just like, just do what he did. You'll copy him. All we had to, I didn't have to speak pure ha, except for know what, copy him. Like, do what he did is like all we had to be able to say. And, and then they would do that just perfectly. And, and so we'd move it up. You know, we'd do some sort of random number of items up to 10. And they basically do perfectly on that. They never get that wrong. I mean, that's not a counting task, right? That is just a match. You just put one against, it doesn't matter how many, I don't need to know how many there are there to do that correctly. And, and they would make mistakes, but very, very few. And no more than MIT undergrads. Just gonna say, like, there's, there's no, this is low stakes.

• 2:40:20Speaker 01

  So, you know, you make mistakes.

• 2:40:21Lex Fridman?

  Counting is not required to complete the matching task.

• 2:40:23Speaker 01

  That's right. Not, not at all. Okay. And so, and, and so that's our control. And this guy, a guy had gone down there before and said that they couldn't do this task. But I just don't know what he did wrong there because they can do this task perfectly well. And, you know, I can, can train my dog to do this task. So of course they can do this task. And so, you know, it's not a hard task. But the other task that was sort of more interesting is like, so then we do a bunch of tasks where you need, some way to encode the set. So like, one, one of them is just a, I, I've just put a, a, um, a opaque sheet in front of the, of the things. I put down a bunch, a set of these things and I put an opaque sheet down. And so you can't see them anymore. And I tell you, do the same thing you were doing before, right? You know, and it's easy if it's two or three, it's very easy.

• 2:41:08Speaker 01

  But if I don't have the words for eight, it's a little harder. Like maybe, you know, with practice, went, well, no.

• 2:41:16Lex Fridman?

  Because you have to count.

• 2:41:17Speaker 01

  For us, for us, it's easy because we just, we just count them. It's just so easy to count them. But, but they don't, they can't count them because they don't count. They don't have words for this thing. And so they would do approximate. It's totally fascinating. So they would get them approximately right. Uh, you know, uh, you know, uh, after four or five, you know, uh, because you can, basically you always get four right. Three or four, that looks, that's something we can visually see. But, but after that, you kind of have, it's an approximate number. And so then, and there was a bunch of tasks we did and they all failed as, I mean, failed. They did approximate after five on all those tasks. And it just kind of shows that the words, uh, you kind of need the words, you know, to be able to do these, these kinds of tasks.

• 2:41:57Lex Fridman?

  There's a little bit of a chicken and egg thing there. Because if you don't have the words, then maybe they'll limit you in the kind of like a little baby Einstein there. Won't be able to come up with a counting task. You know what I mean? Like, uh, the ability to count enables you to come up with interesting things, probably. So, yes, you develop counting because you need it. But then, once you have counting, you can probably come up with a bunch of different inventions. Like how to, I don't know.

• 2:42:29Lex Fridman?

  What kind of thing? They do matching really well for building purposes, building some kind of hut or something like this. So it's interesting that language is a limiter on what you're able to do.

• 2:42:41Speaker 01

  Yeah. Here, language is just, is the words. Here is the words. Like the words for exact count is the limiting factor here. They just don't have them.

• 2:42:50Lex Fridman?

  Yeah.

• 2:42:51Speaker 01

  And this, yeah.

• 2:42:51Lex Fridman?

  Well, that's what I mean.

• 2:42:52Speaker 01

  Yeah, yeah, yeah.

• 2:42:53Lex Fridman?

  The, that limit is also a limit on the society of what they're able to build.

• 2:42:59Speaker 01

  That's going to be true. Yeah. So it's probably, I mean, we don't know. This is one of those problems with the snapshot of just current languages is that we don't know what causes a culture to discover slash invent a counting system. But the hypothesis is, the guess out there is something to do with farming. So if you have a bunch of goats and, uh, you want to keep track of them. And you have, say you have 17 goats and you go to bed at night and you get up in the morning. Boy, it's easier to have a count system to do that. You know, if I have, that's an abstract, abstraction over a set. So that I don't have to like. People often ask me when I talk to them about this kind of work and they say, well, don't these Pirahua, don't they have kids? Don't they have a lot of children? I'm like, yeah, they have a lot of children. And they do. They often have families of three or four or five kids. And they go, well, don't they need the numbers to keep

• 2:43:44Speaker 01

  track of their kids? And I always ask the person who says this, like, do you have children? And the answer is always no, because that's not how you keep track of your kids. You care about their identities. It's very important to me when I go, I think I have five children. It's, it's, it doesn't matter which, yeah, it matters which five. It's like, if you replaced one with someone else, I would, I would care. Goat, maybe not, right? That's the kind of point. It's an abstraction. Something that looks very similar to the one wouldn't matter to me, probably.

• 2:44:13Lex Fridman?

  But if you care about goats, you're gonna know them actually individually also.

• 2:44:17Speaker 01

  Yeah, you will.

• 2:44:18Lex Fridman?

  I mean, cows, goats, if that's a source of food and milk and all that kind of stuff.

• 2:44:21Speaker 01

  You're absolutely right. But, but I'm saying it is an abstraction such that you don't have to care about their identities to do this thing fast. That's, that's the hypothesis, not mine, from anthropologists are guessing about where words for counting came from is from farming, maybe.

• 2:44:36Lex Fridman?

  Yeah. Do you have a sense why universal languages like Esperanto have not taken off?

• 2:44:43Speaker 01

  Um.

• 2:44:44Lex Fridman?

  Like, why do we have all these different languages?

• 2:44:47Speaker 01

  Yeah. Well, my guess is that the function of a language is to do something in a community. And, and, I mean, unless there's some function to that language in the community, it's, it's not going to survive. It's not going to be useful. So here's a great example. So what I'm, like, language death is super common, okay? Languages are dying all around the world. And here's how, here's why they're dying. And it's like, yeah, I see this in, you know, in, it's not happening right now in either the Chimene or the, or the Pirahua, but it probably will. And so there's a neighboring group called Mostitan, which is, I, I, I said that it's a isolate, it's actually, there's a dual, there's two of them. Okay? So it's actually, there's two languages which are really close, which are Mostitan and,

• 2:45:29Speaker 01

  and Chimene, which are unrelated to anything else. And Mostitan is unlike Chimene in that it has a lot of contact with Spanish. And it's dying. So that language is dying. The reason it's dying is there's not a lot of value. For the local people in their native language. So there's much more value in knowing Spanish like because they want to feed their families. And how do you feed your family? You learn Spanish so you can make money, so you can get a job and do these things. And then you can, and then you make money. And so they want Spanish things they want. And so, so most of it is in danger and is dying. And that's normal. And so basically, the problem is that people, the reason we learn languages to communicate

• 2:46:11Speaker 01

  and we need to, we use it to, to make money and to do whatever it is to, to feed our families. And if that's not happening, uh, then it, it won't take off. It's not like a game or something. This is like something we use, like, why is English so popular? It's, it's not because it's an easy language to learn. Maybe it is, I don't really know. It's, but that's not why it's popular.

• 2:46:34Lex Fridman?

  But because it's the, the United States is gigantic economy therefore.

• 2:46:37Speaker 01

  Yeah, it's big economies that do this. It's all it is. It's all about money and that's what, and so, you know, there's a motivation to learn Mandarin. There's a motivation to learn Spanish. There's a motivation to learn English. These languages are very valuable to know because there's so, so many speakers all over the world.

• 2:46:52Lex Fridman?

  That's fascinating.

• 2:46:53Speaker 01

  There's less of a value economically. It's like kind of what drives this. It's not about, it's not a, you know, it's not just for fun. I mean, there are these groups that do want to learn language just for language's sake. And they want, and then, and there's something, you know, to that. But those are rare, those are rarities in general. Those are a few small groups that do that, not most people don't do that.

• 2:47:12Lex Fridman?

  Well, if that was a primary driver, then everybody was speaking English or speaking one language. There's also a tension.

• 2:47:18Speaker 01

  That's happening.

• 2:47:19Lex Fridman?

  Not, well, well.

• 2:47:21Speaker 01

  We're moving towards fewer and fewer languages.

• 2:47:22Lex Fridman?

  We are. I wonder if, you're right, maybe, maybe, you know, this is slow.

• 2:47:27Speaker 01

  Yeah.

• 2:47:27Lex Fridman?

  But maybe that's where we're moving. But there is a tension. You're saying a language that the fringes. But if you look at geopolitics and superpowers, it does seem that there's another thing in tension, which is a language is a national identity sometimes. For certain nations, I mean, that's the, the war in Ukraine. Language, Ukrainian language is a symbol of that war in many ways, like a country finding for its own identity. So it's not merely the convenience, I mean, those two things are a tension, is the convenience of trade and the economics and be able to communicate with neighboring countries and trade more efficiently with neighboring countries, all that kind of stuff, but also identity.

• 2:48:10Speaker 01

  That's right.

• 2:48:10Lex Fridman?

  Of the group.

• 2:48:11Speaker 01

  I completely agree.

• 2:48:12Lex Fridman?

  Because language is the way, for every community, like dialects that emerge are a kind of identity for people.

• 2:48:21Speaker 01

  Yeah.

• 2:48:21Lex Fridman?

  Sometimes a way for people to say F you to the more powerful.

• 2:48:25Speaker 01

  Yeah.

• 2:48:26Lex Fridman?

  People. That's interesting. So in that way, language can be used as that tool.

• 2:48:31Speaker 01

  Yeah, it, I completely agree. And there's a lot of work to try to create that identity so people want to do that. Speak, you know, as a cognitive scientist and language expert, I, I hope that continues because I don't want languages to die. I want languages to survive because I, because they're so interesting for, for so many reasons. But I mean, I, I find them fascinating just for the language part, but I think they, you know, there's a lot of connections to culture as well, which is also very important.

• 2:49:01Lex Fridman?

  Do you have hope for machine translation that can break down the barriers of language? So while all these different diverse languages exist, I guess there's many ways of asking this question, but basically how hard is it to translate in an automated way from one language to another?

• 2:49:20Speaker 01

  There's, there's going to be cases where it's going to be really hard, right? So there are concepts that are in one language and not in another, like the most extreme kinds of cases are these cases of number information. So exactly like, good luck translating a lot of English into Pirahha. It's just impossible. There's no way to do it because there are no words for these concepts that we're talking about. There's probably the flip side, right? There's probably stuff in Pirahá which is going to be hard to translate into English on the other side. And so I just don't know what those concepts are. I mean, you know, the space, the world space is a little, is different from my world space. And so I don't know what, like, so that the things they talk about, things are, you know, it's going to have to do with their life as opposed to, you know, my industrial life, which is going to be different.

• 2:50:05Speaker 01

  And so there's going to be problems like that always. You know, there's like, it's not, maybe it's not so bad in the case of some of these spaces and maybe it's going to be harder than others. And so it's pretty bad in number. It's like, you know, extreme, I'd say, in the number space, you know, exact number space. But in the, in the color dimension, right? So that's not so bad. There's, I mean, but it's a problem that, that you don't have ways to talk about the concepts.

• 2:50:29Lex Fridman?

  And there might be entire concepts that are missing. So to you, it's more about the space of concept versus the space of form. Like form, you can probably map.

• 2:50:38Speaker 01

  Yes. Yeah. But so you were talking earlier about translation and about how translations, there's good and bad translations. I mean, now we're talking about translations of form, right? So what makes a writing good, right?

• 2:50:51Lex Fridman?

  There is a music to the form.

• 2:50:53Speaker 01

  Right. It's not just the content. It's, you know, it's how it's written. And translating that, I, you know, I, you know, that's, that sounds difficult.

• 2:51:01Lex Fridman?

  We should, we should say that there is like, I hesitate to say meaning, but there's a music and a rhythm to the form. When you look at the broad picture, like the Frans Duyt, Dostoevsky and Tolstoy, or Hemingway, Bukowski, James Joyce, like I mentioned, there's a beat to it. There's an edge to it that's like, is in the form.

• 2:51:24Speaker 01

  We can probably get measures of those.

• 2:51:27Lex Fridman?

  Yeah.

• 2:51:28Speaker 01

  I, I, I don't know. I'm optimistic that we could get measures of those things. And so maybe that's.

• 2:51:33Lex Fridman?

  Translatable.

• 2:51:34Speaker 01

  I don't know. I don't know, though. I have not worked on that.

• 2:51:37Lex Fridman?

  I would love to see

• 2:51:38Speaker 01

  That sounds totally fascinating.

• 2:51:39Lex Fridman?

  Translation to Hemingway, I mean Hemingway is probably the lowest. I would love to see different authors, but the average per sentence dependency length for Hemingway is probably the shortest.

• 2:51:54Speaker 01

  That's your sense, huh? It's simple sentences with short, yeah, yeah, yeah, yeah.

• 2:51:59Lex Fridman?

  I mean, that's when, if you have really long sentences, even if they don't have center embedding, like.

• 2:52:03Speaker 01

  They can have longer connections, yeah.

• 2:52:05Lex Fridman?

  They can have longer connections.

• 2:52:06Speaker 01

  They don't have to, right? You can have a long, long sentence with a bunch of local words, yeah.

• 2:52:09Lex Fridman?

  Yeah.

• 2:52:10Speaker 01

  But it's, but it is much more likely to have the possibility of long dependencies with long sentences, yeah.

• 2:52:16Lex Fridman?

  I met a guy named Azaraskin, who, uh, who does a lot of cool stuff, really brilliant, works with Tristan Harrison, a bunch of stuff. But he was talking to me about communicating with animals. He co-founded Earth Species Project, where you're trying to find the common language between whales, crows, and humans. And he was saying that there is a, there's a lot of promising work, that even though the signals are very different.

• 2:52:45Speaker 01

  Right.

• 2:52:45Lex Fridman?

  Like the actual, like, um, if you have embeddings of the languages, they're actually trying to communicate similar type things.

• 2:52:56Lex Fridman?

  Is there something you can comment on that? Like where, is there promise to that? And everything you've seen in different cultures, especially like remote cultures, that this is a possibility? Or no? That we can talk to whales?

• 2:53:08Speaker 01

  I, I, I would say yes. I, I, I think it's not crazy at all. I think it's quite reasonable. There, there's this sort of weird view, well, odd view, I think, that to think that human language is somehow special. I mean, it is, maybe it is. We can certainly do more than any of the other species, you know, we, you know, and so, and maybe, maybe our language system is. Part of that, it's possible. But, but, but people do have often talked about how human, like Chomsky, in fact, has talked about how human only, only human language has, you know, this, you know, this, this compositionality thing that he thinks is sort of key in, in language. And it's, the, the problem with that argument is he doesn't speak whale.

• 2:53:54Speaker 01

  And he doesn't speak crow and he doesn't speak monkey, you know? He's like, they, they say things like, well, they're making a bunch of grunts and squeaks. And, and, and the reasoning is like, that's bad reasoning. Like, you know, I'm pretty sure if you asked a whale what we're saying, they'd say, well, I'm making a bunch of weird noises.

• 2:54:10Lex Fridman?

  Exactly.

• 2:54:11Speaker 01

  And so it's like, this is a very odd reasoning to, to be making that human language is special because we're the only ones have human language. I'm like, well, we don't know what those other, we just don't, we can't talk to them yet. And so there are probably a signal in there and it might very well be something complicated like human language. I mean, sure, with a small brain, in, in, in lower, in lower species, there's probably not a very good communication system, but in these higher, higher species where you have, you know, what seems to be, you know, abilities to communicate something, there might very well be a lot more signal there than we're, than we might have otherwise thought.

• 2:54:50Lex Fridman?

  But, but also if we have a lot of intellectual humility here, as somebody formerly from MIT, Neri Oxman, who I admire very much, has talked a lot about, has worked on communicating with plants.

• 2:55:05Lex Fridman?

  So like, yes, the signal there is even less than, but like, it's not out of the realm of possibility that all nature has a way of communicating. And it's a very different language, but they do develop a kind of language through the chemistry, through some way of communicating with each other. And if you have enough humility about that possibility, I think you can, I think it would be a very interesting, in a few decades, maybe centuries, hopefully not, a humbling possibility of being able to communicate not just between humans effectively, but between all of living things on earth.

• 2:55:44Speaker 01

  Well, I mean, I think some of them are not going to have much interesting to say.

• 2:55:47Lex Fridman?

  But you could still.

• 2:55:48Speaker 01

  We don't know. We certainly don't know.

• 2:55:50Lex Fridman?

  I think if we're humble, there could be some interesting trees out there.

• 2:55:57Speaker 01

  Well, they're probably talking to other trees, right? They're not talking to us. And so to the extent they're talking, they're saying something interesting to some other, you know, you know, conspecific as opposed to us, right? And so there probably is, there may be some signal there. I, you know, so there are people out there, actually, it's pretty common to say that language, that human language is special and different from any other animal communication system. And I, I just, I just don't think the evidence is there for that claim. I think it's not obvious.

• 2:56:28Speaker 01

  You know, we just don't know what, what, because we don't speak these other communication systems until we get better. You know, I do think there's, there are people working on that, as you pointed out, though. People working on whale speak, for instance, like, that's really fascinating.

• 2:56:42Lex Fridman?

  Let me ask you a wild out there sci fi question. If we make contact with an intelligent alien civilization and you get to meet them. How hard do you think, like, how surprised would you be about their way of communicating? Do you think it would be recognizable? Maybe there's some parallels here to when you go to the remote tribes.

• 2:57:03Speaker 01

  I mean, I would want Dan Everett with me. He is like amazing at learning foreign languages. And so he, like, this is an amazing feat, right? To be able to go, this is a language, Pirahua, which has no translators before him. I mean, there were, he was a missionary. Well, there was a guy that had been there before, but he wasn't very good. And so he learned the language far better than anyone else had learned before him. He's like good at, he's just, he's a very social person. I think that's a big part of it is being able to interact. So I don't know, it kind of depends on these, these, this, this species from outer, from outer space, how, how much they want to talk to us.

• 2:57:37Lex Fridman?

  Is there something you can say about the process he follows? Like, what, how do you show up to a tribe and socialize? I mean, I guess colors and counting is a, is one of the most basic things to figure out.

• 2:57:47Speaker 01

  Yeah, you start that, you actually start with like objects.

• 2:57:50Lex Fridman?

  Yes.

• 2:57:50Speaker 01

  And just say, and you just throw a stick down and say, stick. And then you say, what do you call this? And they do this feature and then they'll say the word, whatever. And he says, the standard thing to do is to throw two sticks, two sticks. And then, you know, he learned pretty quick that there weren't any count words in this language, because they didn't know this wasn't interesting. I mean, it was kind of weird. They'd say some or something, the same word over and over again. And so, but that is a standard thing. You just like try to, but you have to be pretty out there socially, like willing to talk to random people, which these are, you know, really very different people from you. And he was, and he's, he's very social. And so I think that's a big part of this is like, that's how, you know, a lot of people know a lot of languages is they're willing to talk to other people.

• 2:58:30Lex Fridman?

  That's a tough one, where you just show up knowing nothing.

• 2:58:32Speaker 01

  Yeah. Oh, God.

• 2:58:33Lex Fridman?

  That's a beautiful, it's beautiful that humans are able to connect in that way.

• 2:58:36Speaker 01

  Yeah, yeah.

• 2:58:38Lex Fridman?

  You've had an incredible career exploring this fascinating topic. What advice would you give to young people about how to have a career like that? Or a life that, that they can be proud of?

• 2:58:51Speaker 01

  When you see something interesting, just go and do it. Like I do, I do that. Like that's something I do, which is kind of unusual for most people. So like, when I saw the, like, if Piero Ha was available to go and visit, I was like, yes, yes, I'll go. And then when we couldn't go back, we had some trouble with the Brazilian government. There's some corrupt people there. It was very difficult to get, go back in there. And so I was like, all right, I gotta find another group. And so we searched around and we were able to find the Chaman, because I wanted to keep working on this kind of problem. And so we found the Chaman and just go there. I didn't really have, we didn't have contact, we had a little bit of contact and brought someone. And that, and that was, you know, we just, you just kind of just try things. I say it's like, a lot of that's just like ambition, just try to do something

• 2:59:33Speaker 01

  that other people haven't done, just give it a shot is what I, I mean, I do that all the time. I don't know.

• 2:59:37Lex Fridman?

  I love it. And I love the fact that your pursuit of fun has landed you here, talking to me. This was an incredible conversation. Ted, you're, you're, you're just a fascinating human being. Thank you for taking a journey through human language with me today. This is awesome.

• 2:59:52Speaker 01

  Thank you very much. It's been a pleasure.

• 2:59:55Lex Fridman?

  Thanks for listening to this conversation with Edward Gibson. To support this podcast, please check out our sponsors in the description. And now let me leave you with some words from Wittgenstein. "The limits of my language mean the limits of my world." Thank you for listening. I hope to see you next time.

• 3:00:31Lex Fridman?

  Thank you.