What Everyone Knows You Know with Steven Pinker

What happens when everyone knows what everyone knows? Neil deGrasse Tyson and comic co-host Chuck Nice dive into human psychology and how recursive common knowledge is the invisible glue holding civilization together with cognitive scientist and author, Steven Pinker.

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

• 0:00Neil deGrasse Tyson?

  Finally got Steven Pinker.

• 0:01Speaker 01

  I know.

• 0:01Neil deGrasse Tyson?

  Okay, yes, we're gonna learn all about how the brain is messed up. We don't need him for that. Coming up. The latest from the mind of Steven Pinker on StarTalk.

• 0:14Neil deGrasse Tyson?

  Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:27Neil deGrasse Tyson?

  This is StarTalk. Special edition. Neil deGrasse Tyson here, you're a personal astrophysicist. And when you hear special edition, that means we have Gary in the house.

• 0:38Speaker 01

  Hey Neil.

• 0:38Neil deGrasse Tyson?

  How you doing Gary?

• 0:39Speaker 02

  I'm good.

• 0:39Neil deGrasse Tyson?

  Chuck E. Baby. That's right. How you doing man? I'm doing great. So, so today, we're talking about common knowledge.

• 0:45Speaker 01

  Yes.

• 0:46Neil deGrasse Tyson?

  Common knowledge.

• 0:48Speaker 01

  Uh huh.

• 0:48Neil deGrasse Tyson?

  But why is that interesting?

• 0:50Speaker 01

  If we think about it, we humans have evolved to be social creatures and we rely upon each other for many things. We use language to communicate and coordinate ourselves. But do we consciously strategize in our social behavior and are we aware of our own signaling when we interact? And to the point, what role does common knowledge play in our everyday lives?

• 1:15Neil deGrasse Tyson?

  I depend on that all the time, just as an educator.

• 1:18Speaker 01

  Fine, but a lot of people won't realize that it is something they're using as a tool. Some people will, as you do. And does it then play a role in the big ticket items like financial crashes or political revolutions? Now, okay, I can drone on, I've said enough, let's introduce our guest.

• 1:34Neil deGrasse Tyson?

  We're gonna connect common knowledge to revolutions.

• 1:38Speaker 01

  Hmm, let's see.

• 1:39Neil deGrasse Tyson?

  Okay. Okay, we've got the world's expert on that.

• 1:44Speaker 01

  Mm hmm.

• 1:45Neil deGrasse Tyson?

  Topic. Yes. Sitting right here. Well, thanks guys. I appreciate that. You know. Hammer, pan left. Steven Pinker. Oh, we went Steven.

• 1:58Neil deGrasse Tyson?

  Steven Pinker, welcome to StarTalk.

• 2:00Speaker 02

  Thank you.

• 2:00Neil deGrasse Tyson?

  My gosh, we go way back.

• 2:02Speaker 01

  We do.

• 2:02Neil deGrasse Tyson?

  Decades. This, I think, is your first time on StarTalk. Bad oversight on our part, because there's no reason for that. You're too active, your, your, stuff you work on is too interesting for it to have gone this long without you being on, so thank you.

• 2:15Speaker 02

  Better late.

• 2:15Neil deGrasse Tyson?

  And I just have to ask up top, are you still winning the best hair for a scientist contest every year?

• 2:21Speaker 02

  Oh, I don't know if the luxuriant flowing hair club for scientists is still active.

• 2:28Neil deGrasse Tyson?

  That's what it was called?

• 2:30Speaker 02

  That is.

• 2:30Neil deGrasse Tyson?

  Luxuriant, flowing hair club for scientists. That means it had no black people in it.

• 2:37Speaker 02

  I think it did, actually. There are, I mean, some impressive dreadlocks.

• 2:40Neil deGrasse Tyson?

  Oh, dread, you can dread your way in.

• 2:42Chuck Nice?

  There's some pretty amazing Afros out there, too.

• 2:45Neil deGrasse Tyson?

  Okay, okay.

• 2:46Speaker 01

  It's a pretty cool club.

• 2:48Speaker 02

  This is a project of the respected scientific outlet, the Journal of Irreproducible Results.

• 2:54Neil deGrasse Tyson?

  Oh, good, okay. We should do a whole episode on them at one point.

• 2:57Speaker 02

  And the Nobel Prizes.

• 2:59Speaker 01

  Nobel Prizes.

• 3:00Speaker 02

  To my children, I've never won one. I'm, that's great.

• 3:04Neil deGrasse Tyson?

  So, you're cognitive psychologist, I think that's what they call you. Do I remember you being a linguist, though, long ago?

• 3:10Speaker 02

  I'm not a professional linguist.

• 3:12Neil deGrasse Tyson?

  But that was your...

• 3:13Speaker 02

  A kind of psycholinguist, which is the psychology of language, which is a branch of cognitive psychology.

• 3:17Neil deGrasse Tyson?

  That's how I first met you and knew your work.

• 3:20Speaker 02

  But for me, language is just one of the amazing things the human mind does. So I'm not, I don't have a PhD in linguistics, but in cognitive psychology.

• 3:27Neil deGrasse Tyson?

  Got it, got it. And I have got you here as the John Stone Family Professor of Psychology at Harvard University. So are you in the famous building, the Psychology Building there?

• 3:37Speaker 02

  William James Hall, the 15-story white building, sticking out like a sore thumb in a Cambridge residential neighborhood.

• 3:44Neil deGrasse Tyson?

  I got you down here for a dozen books. Several of them are some of my favorite books. You know, The Blank Slate, which had its own bit of controversy, but it was fun to see intelligent arguments presented into that space. The Better Angels of Our Nature, oh my gosh.

• 3:59Speaker 02

  That's very, yeah.

• 4:00Neil deGrasse Tyson?

  It has the two words "common knowledge" in the title.

• 4:03Speaker 02

  In the subtitle.

• 4:04Neil deGrasse Tyson?

  Subtitle, so give me the full up title.

• 4:05Speaker 02

  So the title of the book is, "When Everyone Knows That Everyone Knows..." dot, dot, dot. And there's a story behind that. The subtitle is, "Common Knowledge and the Mysteries of Money, Power, and Everyday Life."

• 4:17Chuck Nice?

  Whoa.

• 4:17Speaker 02

  And I can explain all of those things.

• 4:19Neil deGrasse Tyson?

  Leave anything out there.

• 4:20Chuck Nice?

  That is, that's a title. That's actually three titles.

• 4:24Speaker 01

  See, what he done, I mean, I know you're a psychologist, but you've put in mysteries. There you go. And then money and power.

• 4:31Speaker 02

  I should have put in sex, too.

• 4:32Neil deGrasse Tyson?

  Yes. She's completely manipulating the buyer here.

• 4:36Speaker 01

  Of course, absolutely, of course.

• 4:37Chuck Nice?

  Now I want to hear the story behind this title, because that's a lot.

• 4:40Speaker 02

  Okay. So, common knowledge in the technical sense refers to the situation where I know something, you know it. I know that you know it, you know that I know it, I know that you know that I know it, ad infinitum. So it's when everyone knows that everyone knows, and the dot, dot, dot is essential. I had to fight with my editor, he says, "Oh, it'll screw up the computer listings on Amazon."

• 5:00Neil deGrasse Tyson?

  That's the infinity.

• 5:01Speaker 02

  That's the infinity.

• 5:02Neil deGrasse Tyson?

  Yes, yes.

• 5:02Speaker 02

  Because technically, it does mean...

• 5:04Neil deGrasse Tyson?

  You know, the first I saw that was Ralph Cramden in The Honeymooners. "You know that I know that you know that I know..." Norton. Norton.

• 5:12Speaker 02

  "Oh my god, I didn't put that in the book."

• 5:14Neil deGrasse Tyson?

  Norton, actually, that's Eddie Murphy. No, no, he's imitating... He's imitating the actual Honeymooners, right. You know that I know that you know that I know it.

• 5:22Speaker 02

  I can't believe I left that out.

• 5:24Neil deGrasse Tyson?

  Yeah, that was my first encounter with the infinity.

• 5:26Speaker 02

  I gotta look that up.

• 5:27Neil deGrasse Tyson?

  Of this, yeah. Yeah, yeah, yeah, yeah, you're right.

• 5:29Speaker 02

  That belongs.

• 5:30Neil deGrasse Tyson?

  And if not the original, then it's definitely Eddie Murphy imitating them.

• 5:32Speaker 02

  Right, just as good. Uh, maybe better. Yeah, so to be distinguished from private knowledge, where everyone knows something that they may not know that everyone else knows it. And that makes a big difference. It does. Wow.

• 5:45Neil deGrasse Tyson?

  I never thought to think about that.

• 5:46Speaker 02

  It's been explored by game theorists, the branch of mathematics, dealing with the best strategy when other people are dealing with, have their own strategies. It's a big deal in economics, for reasons that we'll, we'll get to. It's been studied by philosophers. But it is a psychological phenomenon. It's getting in the heads of other people when they're getting into your heads, or still other people's heads. Um, and they've never been explored from a psychological point of view. Now, why is this significant? The reason that it's important is that common knowledge is necessary for coordination. That is, for two people being on the same page, doing things that benefit them both as long as each one can expect the other one to do it and expect it to...

• 6:24Neil deGrasse Tyson?

  Don't we call that civilization?

• 6:26Speaker 02

  Well, civilization does depend on coordination, on institutions like government, like money. That's, the reason it's in the subtitle is, the only reason that a piece of paper with Abraham Lincoln on it is valuable is because other people treat it as valuable. Now, why do they treat it as valuable? Well, because they know that other people will treat it as valuable. That's what makes it a currency. Likewise, for power. There's no way a government can intimidate every last member of its citizenry. Um, and...

• 6:54Neil deGrasse Tyson?

  Give it time. I'm working on it.

• 6:59Speaker 02

  I recognize the impression.

• 7:04Speaker 02

  But the government has power, a president is a president, and a governor is a governor, and the chairman of the board is the chairman of the board, because everyone treats them as if they are. It's a social reality. Our corporations, our religions, our gods, our conventions, even language itself, what makes the word rose refer to a rose, it smells just as sweet by any other name. Rose means rose because everyone knows it means rose, and everyone knows that everyone knows. So all of our conventions, all of our ways of coordinating, all of our harmony, depends on common knowledge. Just to give a concrete example, from Thomas Schelling, the political scientist and economist, who was one of the originators of the concept. Imagine that, say, a husband and wife get lost in Manhattan.

• 7:47Speaker 02

  This is the era before cell phones. How can they meet up? He can think, well, she likes to go to a bookstore, so I'll meet her there, but then thinks, oh, but she knows that I like to go to a camera store, so maybe she'll go to the camera store. Then she knows that I know that she'll, that she likes to go to the bookstore, so she'll go to the bookstore after all. Meanwhile, each of them can kind of ricochet with this useless empathy, and still not end up at the same place at the same time. Nothing short of common knowledge, not only knowing something, but knowing that the other person knows that you know, gets them together. Now, common knowledge can be generated by language, and that's how I got into it, that is, in this case, a cellphone call, although it can also just be a convention, something that everyone assumes that just coordinates everyone, like,

• 8:31Speaker 02

  what day of the week do you stay home? Sunday? Why Sunday? Well, because everyone else stays home on Sunday, so that's a good reason for me to do it if everyone else is doing it. So a lot of our society depends on common knowledge. This immediately raises a question. People say, well, you define common knowledge as I know that she knows that I know that she knows that I know that she knows, but no one can keep track of them. That's why you have plots like The Honeymooners, or there's an episode in Friends that people always tell me about where Rachel says, Joey, they don't know that we know that we know they know that we know. You can't say anything. And he says, I couldn't even if I wanted to. The point being that your head starts to spin when you keep, have to keep track of more than two or three layers of I know that she knows. So how is this possible? Well, the reason it's possible is that we can get common knowledge at a stroke when

• 9:15Speaker 02

  there is something that we sense to be public, or out there, or salient, or you can't miss it, or it's in your face. So if I see something, at the same time as I see you see it... Then that implicitly packs into it as many layers as we would ever need. We don't have to think them all through. But it also means that we're really, really sensitive to something that is public, that you can't ignore versus something that may be known privately. And I have chapters in the book on how that shapes our language, why we don't just blurt out what we mean, but often veil our intentions in euphemism and innuendo to prevent things from being common knowledge. phenomena like being in the closet or- For any, whatever is the reason.

• 9:59Speaker 02

  Well, and it used to be, it used to be the gay- That's where my clothes are, that's why I'm in the closet. Well, my graduate- That means you have a walk-in closet, I didn't know that. Very good.

• 10:10Speaker 02

  Well, my graduate advisor, actually, he insisted he was not gay. He was a homosexual to be- In the day. In the day, that's right. And he said that to be gay, you have to be born in the 50s or later. He was born in the 20s. But no one ever acknowledged that he was gay, and he would never acknowledge it. Someone who described him as a bachelor. Now, each of us knew- Confirmed bachelor. Confirmed bachelor. Until he was in his late 50s, when he finally, as we say, came out. Now, notice the metaphors. In the closet means that it's not public, you can't see it. Coming out means not only can you see him, but you know, you can see everyone else seeing him. But that's a good metaphor for common knowledge. And common knowledge in general governs our relationships as well as our institutions.

• 10:54Speaker 02

  So it's not just money and power. The everyday life in the subtitle comes from the fact that our relationships of deference, of intimacy, of friendship, romantic relationships, transactional relationships, they all exist because both parties know they exist. What does it mean to be friends? It's not like you sign a contract. Well, it's an implicit contract, in a way. It is implicit, and it's a complex, that depends on common knowledge. Namely, what does it mean for us to be friends? It means that I know that you know that we're friends, and I know that you know that I know that we're friends. That's all there is to it. And so sometimes when we don't want to threaten a relationship, we might avoid common knowledge by hinting, slipping in our intentions as eating around the bush, euphemism, you kind of catch my drift, you connect the dots.

• 11:37Speaker 02

  Whereas if you blurt it out, then that changes the nature of the relationship.

• 11:51Speaker 04

  Hey, this is Kevin the Sommelier, and I support StarTalk on Patreon. You're listening to StarTalk with Neil deGrasse Tyson.

• 12:05Chuck Nice?

  So what about those where I'll see the common knowledge, but there is what I'll call an acceptable duplicity?

• 12:14Speaker 02

  Yeah.

• 12:14Neil deGrasse Tyson?

  A two-way duplicity.

• 12:15Chuck Nice?

  A two-way duplicity. Like, we're both aware of it.

• 12:17Speaker 02

  Yeah.

• 12:18Chuck Nice?

  But at the same time, I don't want to upset the apple cart because what we got here is good.

• 12:23Speaker 02

  That's exactly what I talk about. I have a chapter called Weasel Words.

• 12:29Chuck Nice?

  Weasel Words?

• 12:30Speaker 02

  Yes.

• 12:31Chuck Nice?

  That sounds like a fun chapter.

• 12:32Speaker 02

  But acceptable duplicity, when, I mean, there's all kinds of, you know, benign hypocrisy. The politician who resigns to spend more time with his family.

• 12:41Chuck Nice?

  Right.

• 12:42Speaker 02

  The escort services. Would you like to come up for Netflix and chill? Let's say you were trying to bribe a maître d' to jump the queue and be seated immediately. You might, kind of holding out a $50 bill in peripheral vision, say, "Is there anything you can do to shorten my wait? I was wondering if you might have a cancellation."

• 13:00Chuck Nice?

  Right.

• 13:01Neil deGrasse Tyson?

  A $50 cancellation.

• 13:03Speaker 02

  And not, "If I give you 50, will you seat me right away?"

• 13:06Chuck Nice?

  Exactly. Because that would be crass.

• 13:08Speaker 02

  And so what does it mean for it to be crass? What it means is you're disrespecting the relationship you have, where he is the authority, and he seats you where and when he pleases. You're treating him like a transactional relationship, which is a very different kind of human relationship.

• 13:23Neil deGrasse Tyson?

  Interesting.

• 13:24Speaker 02

  Likewise, what's the difference between, "You want to come up for Netflix and chill", and "You want to come up for sex"? Well, with Netflix and chill, there isn't really plausible deniability. I mean, you know, she's a grown-up, she knows what it means. But she could have some doubt that you know that she knows that you know what it means. And she could think, "Well, maybe he thinks I'm naive and I'm just turning down an invitation to a movie." He could think, "Well, maybe she thinks I'm dense and that I might think she's naive, or I might think that she doesn't realize that I'm not naive." And so they can maintain, go back to their platonic relationship. They haven't jumped.

• 13:57Neil deGrasse Tyson?

  Plausible deniability.

• 13:59Speaker 02

  Well, it's plausible deniability of common knowledge. Because when you think about it, it's really not that plausible.

• 14:03Chuck Nice?

  Right, everybody knows, but like you said.

• 14:05Speaker 02

  The thing is, everyone may not know that everyone knows.

• 14:07Chuck Nice?

  Exactly, and what that does is it allows you to save face.

• 14:12Speaker 02

  So, saving face, by the way, another great, going back to the idea, how could, if common knowledge is so important, as I say it is, and it requires, I know that she knows, which makes your head hurt, how could it work so well? And one of the reasons is that we talk about it, not using the language of philosophy or game theory, but metaphors of something being visible out in the open. That's why we use expressions like in the closet or saving face. Face is a part of you that other people see and that you use to see other people. So, saving face or losing face is a great metaphor for common knowledge.

• 14:46Neil deGrasse Tyson?

  It's really saving the facade of your face.

• 14:47Speaker 02

  Yeah.

• 14:48Neil deGrasse Tyson?

  In a way, right, saving the face that you had established prior.

• 14:52Speaker 02

  Face and facade are related.

• 14:54Neil deGrasse Tyson?

  I guess so. Do you know, in the movie Back to the Future, there's a deleted scene, which.

• 14:59Chuck Nice?

  How could I know that?

• 15:04Neil deGrasse Tyson?

  Where the doc is setting up his connection to the clock in anticipation of the lightning strike.

• 15:10Chuck Nice?

  Okay.

• 15:11Neil deGrasse Tyson?

  And the cop comes by and say, oh, doc, what you doing? I'm just doing some weather, give me his voice, some weather experiment.

• 15:17Chuck Nice?

  I'm doing some weather experiments.

• 15:19Neil deGrasse Tyson?

  Thank you. And then, and so then, and he said, you got a permit for that? And he says, of course I do. Okay, so then he comes down and goes up to him, this is the deleted scene. He walks up to him, opens his wallet, and there's just cash there.

• 15:35Chuck Nice?

  Oh, my goodness.

• 15:36Neil deGrasse Tyson?

  Doesn't have his permit.

• 15:38Chuck Nice?

  I didn't, oh, I was about to say, I didn't see that.

• 15:43Neil deGrasse Tyson?

  So, he bribed him, but that's kind of out of character with how he is. He's just a lovable, doddering, old scientist.

• 15:49Chuck Nice?

  That would have damaged his character.

• 15:51Neil deGrasse Tyson?

  It would have damaged the character.

• 15:52Chuck Nice?

  Yeah, that would have damaged the character.

• 15:53Speaker 02

  That would have been a perfect example.

• 15:54Neil deGrasse Tyson?

  It's transactional.

• 15:55Speaker 02

  It's true. Well, the thing is that it's, in fact, transactional, but it's very dangerous to suggest to a cop that you have a transaction. In fact, it's illegal.

• 16:06Speaker 02

  Makes it visible. Exactly. That's all it is. So that, so there is. It's somewhere in here. And so, you know, it's not plausibly deniable, but it's deniable that the other person knows that you know, or knows that you know that he knows that you know.

• 16:18Chuck Nice?

  Right.

• 16:19Speaker 02

  And that's what, that's what flips it from deference and respect and authority to transactional. And you want to avoid that flip, but you still want to do business. Right.

• 16:28Chuck Nice?

  That's why they're reasonable. Cause I'm from Philly and it was, of course, Philadelphia politicians, but I forget the name of the scandal, but it was very famous because they caught it on tape. And only one politician didn't go for it, but these people, these, the, these feds dressed up as like Saudi businessmen.

• 16:48Speaker 02

  Oh.

• 16:48Chuck Nice?

  And they.

• 16:49Speaker 02

  Abscam.

• 16:50Chuck Nice?

  Abscam, that's exactly right.

• 16:52Speaker 02

  Abscam, nineteen eighty.

• 16:52Chuck Nice?

  And they had like piles of money, like in, sitting out.

• 16:56Speaker 02

  That's been done a number of times around the world.

• 16:58Chuck Nice?

  As they were discussing what they wanted.

• 17:01Speaker 02

  Oh.

• 17:02Chuck Nice?

  And then only one of the politicians was just like, yeah, I'm not worried about that. Let's talk about, and everybody else went down.

• 17:09Speaker 02

  They went down. It was, it was the financial seduction is what that was.

• 17:13Chuck Nice?

  But they never said, this money is yours. They just put a pile of money in front of them. And they were like, so let's talk about the new rail line.

• 17:20Speaker 02

  It was veiled bribes. Veiled bribe, okay. Veiled threats.

• 17:23Chuck Nice?

  Veiled threats.

• 17:24Speaker 02

  Like the, I, I quote an episode from The Sopranos in which a member of the family approaches a high school acquaintance and says, hey, great to see you, Danny. Um, I hear you're on the, uh, jury for the Soprano trial. It's an important civic responsibility that we should all take part in. You've got a wife and kids. We know you'll do the right thing.

• 17:41Chuck Nice?

  Oh.

• 17:43Speaker 02

  So that's a veiled bribe. Right. Now, of course bribes, extortion is illegal. Right, right. I mean, you know, in, in everyday life, there are occasions where there are implicit veiled threats that you don't spell out in so many words, because that establishes a relationship of dominance. And you may want to avoid that relationship while still getting the message through. That completely changed the dynamic. Change of the dynamic. So that's what that chapter is about.

• 18:04Chuck Nice?

  That doesn't happen in the black community. It's just like, I will kick your ass.

• 18:10Neil deGrasse Tyson?

  It's resolved in the moment.

• 18:11Chuck Nice?

  It's resolved in the moment. What? What just happened? I will kick your ass. No.

• 18:18Speaker 02

  Well, there are, I mean, so that's a case where the relationship of dominance is already established. Dominance.

• 18:23Neil deGrasse Tyson?

  That's the exact scene in Coming to America.

• 18:26Speaker 02

  Is it?

• 18:26Neil deGrasse Tyson?

  Where, where they're at the McDowell's home and the king says, how much for your daughter?

• 18:34Chuck Nice?

  Oh, okay.

• 18:35Neil deGrasse Tyson?

  Yeah. And this is, this is America, Jack. And you better stop me before I put my foot up your ass.

• 18:41Chuck Nice?

  Right. Was that John Amos?

• 18:43Neil deGrasse Tyson?

  Yeah, John, yeah, yeah, yeah.

• 18:44Chuck Nice?

  I forget the exact words.

• 18:45Neil deGrasse Tyson?

  In the moment. Right, there was, it was a, because it's a king and just like a rich American.

• 18:49Speaker 02

  Another great example, so how, why do cultures differ from each other? Well, there, if you think of the different kinds of relationships, so there, the basic kinds of relationships are communal sharing, warmth, intimacy, that's one model.

• 19:01Neil deGrasse Tyson?

  Not America.

• 19:03Speaker 02

  Well, another model is.

• 19:07Neil deGrasse Tyson?

  What's mine is mine, what's yours is mine. And then that's.

• 19:10Speaker 02

  Well, there's, there's, there's actually a twist on that. So another relationship is hierarchy, you know, alpha male, pecking order, top dog. And the third one is transactional. Now, where cultures differ is not across the board, but in what kind of relationships? Parent, child, student, teacher, employee, boss, friend, friend. What resource? Money, favors, sex? And in what context? Home, school, public? If you mix and match those, that's, gives you kind of all the variation from Anthro 101. And so there's certain resource. So for example, there are cultures that really openly trade brides or, you know, daughters to become brides.

• 19:53Speaker 02

  Ours doesn't commoditize that explicitly, but we do say buy and sell land, which some cultures don't do, where the land might be communal. And so if you think of all the resources, all the contexts, all the.

• 20:04Neil deGrasse Tyson?

  It's quite the matrix of.

• 20:06Speaker 02

  That's the matrix. That's kind of the matrix of Anthro 101.

• 20:09Speaker 01

  Wow. So if we look at common knowledge as a variant of culture and different cultures prize certain common knowledge differently, how often do we get the misinterpretation?

• 20:21Speaker 01

  Of our common knowledge.

• 20:22Speaker 02

  We often get misinterpretations when they're cross-cultural encounters.

• 20:25Speaker 01

  Exactly, yeah.

• 20:26Speaker 02

  And that's part of what culture shock is. You don't know what are the, what is the common knowledge in the new community that you have to deal with. And that can result in war. It could result in war. I mean, it can result in misunderstanding, sometimes comical ones, and it's used in comedy, as in Coming to America, as in Borat, where you have the bumpkin from one culture using the assumptions that were native to that guy's culture but completely inappropriate, sometimes leading to embarrassment, sometimes to shock and outrage.

• 20:57Speaker 01

  Yeah. And then if we look at the communication through body language or unintentional signaling.

• 21:03Speaker 02

  Yeah. So there's a, I have a chapter called Laughing, Crying, Blushing, Staring, Glaring, about non-verbal common knowledge.

• 21:12Speaker 01

  Couldn't get a long title then.

• 21:14Neil deGrasse Tyson?

  Laughing.

• 21:16Speaker 02

  Crying. Blushing.

• 21:17Neil deGrasse Tyson?

  Blushing.

• 21:18Speaker 02

  Staring.

• 21:18Speaker 01

  Glaring.

• 21:19Neil deGrasse Tyson?

  Glaring, okay.

• 21:21Speaker 02

  Now, we have dozens, maybe hundreds of facial expressions, you know, smiling and frowning and grimacing and so on. But on top of that, we have some really conspicuous forms of non-verbal communication that have puzzled people for millennia, such as laughing. Why do we interrupt our speech with that staccato noise?

• 21:40Neil deGrasse Tyson?

  Yes, Stephen, why?

• 21:42Speaker 02

  I thought you'd never ask. Because Chuck needs to pay his mortgage.

• 21:46Speaker 02

  I mean, come on!

• 21:47Neil deGrasse Tyson?

  I forgot. There's a whole profession that depends on this, yes.

• 21:50Speaker 02

  Yes. So what I argue is that for these conspicuous displays, blushing is another one. Why should blood go to your cheeks? Crying, why should a fluid drip from your eyes? Why do you shed tears? I suggest that they are common knowledge generators. So when you're laughing, you know you're laughing because your breathing is interrupted. Other people know you're laughing because they can hear it. Other people know that you know, you know that other people know, et cetera. Blushing, you feel the heat of the blood, the inside in your cheeks, knowing that other people can see the change in color from the outside, and they know that you know that you're feeling it, all the more so when they say, "You're blushing." I've never had that problem.

• 22:30Neil deGrasse Tyson?

  Yes, it's not a black people.

• 22:32Speaker 02

  That's why Stephen pointed at me.

• 22:33Neil deGrasse Tyson?

  It's a lesser, it's a lesser thing.

• 22:35Speaker 02

  Okay, so maybe you can, so Darwin worried about this. Because Darwin was a big proponent of universal emotions. In fact, for him-

• 22:43Neil deGrasse Tyson?

  He had a whole book on it.

• 22:44Speaker 02

  A whole book on it, the expression of the emotions in animals and men.

• 22:47Neil deGrasse Tyson?

  Yes, yes.

• 22:48Speaker 02

  And in fact, he used it, in fact, as an argument against the, the kind of the scientific racism of his day, which said that the different races were independently-

• 22:57Neil deGrasse Tyson?

  Evolved.

• 22:58Speaker 02

  Evolved or created, one or the other, either one. And he said that the similarity in facial expressions, in many other aspects of emotion, showed that we all descended pretty recently from a common ancestor. And his data, I mean, he was, you know, kind of an invalid, but he corresponded with colonial officers and missionaries and traders all over the world, and he had them, he gave them questionnaires to ask of their interactions with the local people, which they then mailed back to him.

• 23:29Neil deGrasse Tyson?

  Just to be in context, this is before photography could capture it.

• 23:32Speaker 02

  Right.

• 23:33Neil deGrasse Tyson?

  I'm just at the dawn of photography, what that is.

• 23:36Speaker 02

  In fact, his, well, his book, this book that we're talking about was the first use of scientific photography. Although not for cross-cultural studies, because the missionaries didn't have cameras out there in the field. But he actually used it to analyze the musculature in facial expressions, including studies where they got a person in an asylum, and they shocked the different muscles to see what they did to a facial expression. Wow. That was a bit of a digression. Going back to the question, though, of-

• 24:05Neil deGrasse Tyson?

  In silos, all they ever use is electricity on you. That's what it seems like.

• 24:09Speaker 02

  That's right. But he asked the question, do dark-skinned people's blush, and is it detectable? And at least the answer from him, and the answer that I got from Nina Jablonski, who's an expert on skin color, is yes. It may not be-

• 24:22Neil deGrasse Tyson?

  I'm not denying it, I'm just saying it's not, it's not an active referent in our comments of people's emotions.

• 24:28Speaker 02

  But I even cite a Ghanaian physician.

• 24:31Neil deGrasse Tyson?

  Ghana, Ghanaian?

• 24:32Speaker 02

  Yes, very dark-skinned. He said, "Well, my mother can tell when I'm blushing." It's a change in color. Anyway, the point is that it's a common knowledge generator in that you know that you're experiencing it, you know that other people can see you experiencing it, they know that you know you're experiencing it. Tears, you're looking at the world through a scrim of fluid. It blurs your vision. At the same time that other people can see the glistening or the trickle. Yeah. So again, you know that you're crying. Other people know that you know that they know. And eye contact is the ultimate common knowledge generator. Because you're looking at the part of the person that's looking at the part of you that's looking at the part of them that's looking at the part of you. No, ad infinitum. Here we go again. Although you don't have to think about it, ad infinitum.

• 25:17Neil deGrasse Tyson?

  But what about this eyebrow thing? The eyebrow, like, why should that mean anything other than what it means?

• 25:23Speaker 02

  Well, Darwin dealt with that in the book. Where he noted that some facial expressions are vestiges or remnants of facial postures that animals do when they're about to attack or they're defending themselves. So in the case of the fear expression, he noted that if you're likely to be a prey animal or someone who's going to be picked on by the alpha, you've got to open your eyes wide to see where threats might be coming from. If on the other hand, you're the predator or you're the alpha. You want to focus. Exactly. Yeah. And if you, the remnants of that include, and so the furrowing your brows, which I think narrows the field of vision. That may even narrow, if the folds of skin actually intrude on the pupils,

• 26:08Speaker 02

  might increase depth of field.

• 26:10Neil deGrasse Tyson?

  Yes, it does.

• 26:10Speaker 02

  That is, you see.

• 26:11Neil deGrasse Tyson?

  Optically. Mm-hmm. That's why people, if they don't have their glasses on.

• 26:15Speaker 02

  They squint.

• 26:15Neil deGrasse Tyson?

  And they squint.

• 26:16Speaker 02

  They squint, exactly.

• 26:17Neil deGrasse Tyson?

  They don't even know that they're increasing their depth of field by doing so. I mean, they're not actively thinking it. They just know they see better.

• 26:22Speaker 02

  Going back to the, these non-verbal common knowledge generators, we use them to make something public that formerly was private. That's the common denominator.

• 26:33Neil deGrasse Tyson?

  Within us.

• 26:34Speaker 02

  Yes. So in the case of eye contact, now that developed way before we were humans. Because among primates, eye contact is a threat signal. The dominant stares at the subordinate who looks away. Which is, by the way, also true in humans. The boss looks at the employee. Don't make eye contact. People, what would they think then?

• 26:50Chuck Nice?

  That was the first thing I was told when I came to New York City as a kid. We were on the subway and they said, whatever you do, do not make eye contact.

• 26:57Speaker 02

  I'm saying, you looking at me?

• 26:58Speaker 01

  Right.

• 27:00Chuck Nice?

  Who you looking at?

• 27:01Speaker 01

  A young person walked past me yesterday evening, and I'm thinking, if you don't look up, you are going to walk into me. And it was intentional not to make any eye contact.

• 27:10Speaker 02

  Well, my anthropologist, Irv Dvor, used to tell us class, if two human beings look into each other's eyes anywhere on earth for more than six seconds, then either they're gonna have sex or one of them's gonna kill the other one.

• 27:21Chuck Nice?

  That is so true!

• 27:23Speaker 02

  There you go.

• 27:24Chuck Nice?

  Oh my gosh!

• 27:25Neil deGrasse Tyson?

  What a great saying!

• 27:27Chuck Nice?

  That is true! It's true! So why is this so uncomfortable? I mean, even, like, I don't mind making eye contact, especially if the person's decent looking. Like, I've gotta tell you, when somebody's unattractive, I'm... Ooh, it's tough.

• 27:41Speaker 02

  Yeah.

• 27:41Chuck Nice?

  I'm just saying. It is rough to look at somebody who is not attractive and, like, maintain eye contact. But prolonged eye contact, and I don't know if it's just me, but I'm just gonna put it out there, I'm gonna be honest, it gets a little, like, creepy and uncomfortable.

• 27:54Speaker 02

  Oh, it absolutely does. Okay, so, and I actually write about this. So, what we call eye contact in ordinary conversation is, it's a bit of a misnomer. Your eyes kinda dance all over the face.

• 28:04Chuck Nice?

  Yeah, all the time.

• 28:04Speaker 02

  You spend a lot of time lip-reading, but it's the eyeball-to-eyeball stare that's really, which is something different. Now, we're humans, we're not, you know, we're not monkeys, we're not gorillas, and so, eye contact doesn't have one meaning. I mean, it can be seduction, it can be threat, but more generally, it can be something that formerly was private knowledge is, as of this moment, common knowledge. Which is why we say things like, "Can you look me in the eye and say that?"

• 28:34Chuck Nice?

  That's great! Tell me the truth! That means you're telling the truth.

• 28:36Speaker 01

  So basically, we're trying to interpret so many different things, and that's why you get uncomfortable.

• 28:40Speaker 02

  And while you're, when you're embarrassed,

• 28:42Speaker 01

  Yeah.

• 28:42Speaker 02

  you look down, you look away, you avoid making eye contact. So, and what laughter does is it makes what used to be private knowledge, common knowledge, where it's some indignity, or infirmity, or weakness of some butt of the joke. Now that can be someone that you're trying to bring down. It could be someone you're trying to keep down in aggressive humor. Yeah. Although it can also, there's also, of course, convivial humor, what, you know, what we've all been doing, where the signaling is to reinforce the egalitarianism that's the basis of warmth and friendship. Because any two, there's always a danger of dominance creeping in. You know, with any two people, one of them is going to be, you know, more, better looking, smarter, richer, more powerful.

• 29:27Speaker 02

  But that's not what you want to do with your friends. With your friends, it's like, we are all on the same level. And so by calling attention to some weakness in yourself, that you could lord over people, but you don't want to lord over people, or vice versa, gentle teasing and joshing that the other person accepts, then you're re-establishing the common knowledge that the basis of our relationship is... Self-depreciation. Yes, exactly.

• 29:51Neil deGrasse Tyson?

  So what does one, what does one do for, is it, whatever the number is, is it one out of 10 or one out of six of us who's on the spectrum? Where social cues do not play.

• 30:04Speaker 02

  Exactly.

• 30:04Neil deGrasse Tyson?

  Might that be adaptive? Where now, you don't know anything about me because my facial expressions are not responding, and therefore, I'm not revealing my inner secrets to you.

• 30:16Speaker 02

  Well, there is the...

• 30:17Neil deGrasse Tyson?

  That could have survival value.

• 30:19Speaker 02

  You know, I suspect that's more likely used strategically, as in the poker face. That is poker face where you deliberately hide the tells. Yeah. In a case where you're not in a situation of cooperation, but zero-sum competition.

• 30:34Neil deGrasse Tyson?

  Right.

• 30:34Speaker 02

  Then any, any kind of tell could be used to your disadvantage.

• 30:37Neil deGrasse Tyson?

  Yeah.

• 30:38Chuck Nice?

  That's why I don't play poker.

• 30:39Speaker 02

  Okay.

• 30:40Chuck Nice?

  Because I'm the worst. It's just, damn!

• 30:42Speaker 02

  Oh! Just kidding.

• 31:06Speaker 01

  All right, to go back briefly to the animal scene.

• 31:09Speaker 02

  Yeah.

• 31:09Speaker 01

  What about the elephant in the room? You know, the emperor's new clothes scenario?

• 31:14Speaker 02

  So, I actually opened the book with the emperor's new clothes, because that's a story about common knowledge.

• 31:20Speaker 01

  Yes.

• 31:20Speaker 02

  When the little boy said the emperor was naked, he wasn't telling anyone anything they didn't already know. But he was changing their knowledge, because when he blurted it out in public, now everyone knew that everyone else knew that everyone else knew. So he converted private knowledge to common knowledge. So first of all, that made a difference. That's the climax of the story. What it is, it changed their relationship with the emperor from deference to ridicule and scorn. So a relationship of deference.

• 31:50Neil deGrasse Tyson?

  To the tailor?

• 31:53Speaker 02

  Well, but to the emperor too. At least in the...

• 31:55Neil deGrasse Tyson?

  The tailor, but the tailor fooled him. It's the tailor's fault, it's not the emperor's fault.

• 31:59Chuck Nice?

  Which is why I'm gonna have him killed. Right away, as if he was clinging to a boat.

• 32:10Neil deGrasse Tyson?

  Did I have a Disneyfied version of that story? I mean, the tailor is the one who should be...

• 32:15Speaker 02

  Yes, but at that moment in public, it was the emperor.

• 32:18Chuck Nice?

  The emperor suffers all of the embarrassment.

• 32:20Speaker 02

  Especially in the Danny Kaye version of the story, where it was met with ridicule and scorn, you know, lyrics to the song.

• 32:28Neil deGrasse Tyson?

  Okay.

• 32:29Speaker 02

  And deference is a matter of common knowledge. You defer to someone because you know they'll stand their ground. Why do they stand their ground? Because they know that you'll defer to them. Why do you, and how do they know that? Well, because you know that they know that they'll stand their ground ad infinitum.

• 32:44Chuck Nice?

  And what about the mutuality of respect? I mean, that's the flip side of that. Sometimes there's a matter of deference because you truly respect the person. They understand that you truly respect them, and they respect that, you know?

• 32:59Speaker 02

  Yeah, there are different flavors of the hierarchical relationship. It could be dominance, which basically means, you know, "I could hurt you if I..." Wanted to, there can be status, I could help you if I wanted to. There can be expertise, you're, there's, you all have a common interest in the decisions being made by someone who knows what they're talking about, or even sometimes if everyone's going in, you know, the expression herding cats. Uh, even if no one has a particular reason to be the, the decider. It's best for everyone if there is a decider and that can give you a hierarchical relationship. But we do use metaphors like saving face out there.

• 33:37Chuck Nice?

  Yeah.

• 33:37Speaker 02

  Uh, and the elephant in the room is obviously something that everyone can see and you can't ignore.

• 33:42Chuck Nice?

  Right, yeah, makes sense.

• 33:44Neil deGrasse Tyson?

  So the elephant in the room is the emperor's new clothes because no one is talking about it.

• 33:48Speaker 02

  That's right.

• 33:48Neil deGrasse Tyson?

  Even though everyone knows that it's there.

• 33:50Chuck Nice?

  Which is why the, uh, the saying always is, let's acknowledge the elephant in the room. In other words, like we all see it, now let's talk about, yeah, yeah.

• 33:58Speaker 01

  Listening to you so far, I get the feeling that there's a kind of a logic to common knowledge and maybe even like a code. And that might then culturally vary.

• 34:06Speaker 02

  Yes. So I think the phenomenon of common knowledge and, and things that generate it like blunt speech, like eye contact is universal. But then what are the relationships that are negotiated with common knowledge or ratified by common knowledge? That is, what can friends share? What can a boss demand of an employee? Uh, how is sex treated? Is it, can it be transactional or is it only intimate? All of these mixing and matching of resources, relationship models and contexts. That's what makes cultures differ from one another. But in each case, there is some kind of common knowledge that holds the relationship in place. That sets out what you're allowed to exchange, what you're allowed to hoard, what you're allowed to demand.

• 34:51Speaker 02

  And that's what it means to be a competent member of a culture to master that. Each one of them being a matter of common knowledge.

• 34:57Neil deGrasse Tyson?

  So Stephen, I try to know what is common knowledge so that I can access it as an educator. I can tap it into it, I can add to it because I don't have to train people to know things that represent common knowledge. Comedians, your joke does not work. Unless, everybody knows what you're talking about.

• 35:18Chuck Nice?

  The more universal, the better. And by universal, I mean...

• 35:21Neil deGrasse Tyson?

  You mean earthwide?

• 35:22Chuck Nice?

  I'm sorry.

• 35:23Neil deGrasse Tyson?

  I'm an astrophysicist here. Correct yourself.

• 35:25Chuck Nice?

  Okay. The more commonly accepted, the better.

• 35:29Neil deGrasse Tyson?

  The more earthwide.

• 35:30Chuck Nice?

  Right. The more earthwide, the better. But really, it's about experiential, um, knowledge. If I, even if you've never been through what I am talking about, if I can put you there, then you will laugh with me. There are many people, many comedians that talk about marriage, and people who are single, laugh. Because they have observed somebody else in a relationship that they understand what this comedian is talking about.

• 35:58Neil deGrasse Tyson?

  That broadens your access points to the person.

• 36:01Chuck Nice?

  For instance, when Steven was talking about the lost couple, and the woman was going to a bookstore, and the man was going to a camera shop, the first thing that popped into my head was, "Well, listen, if you know what's good for you, you better go to that damn bookstore." Because every husband knows that if I don't show up at the bookstore, I'm in trouble. And that's the first thing that popped into my head.

• 36:23Speaker 02

  Now, this is an important point, because what humor often does is it establishes, uh, common knowledge. That is, if you get the joke, then what has just been made public is something that you privately knew along. And so you get that feeling of solidarity with the other person. If you're laughing at the same thing, then what was unstated that makes the joke funny is something that you have in common. That's why humor is such an important bonding agent. For, in dating, uh, one of the main criteria that, in, in, um, accepting a mate is...

• 36:54Neil deGrasse Tyson?

  Sense of humor.

• 36:54Speaker 02

  Sense of humor. And, and, and sense of humor has to be...

• 36:57Neil deGrasse Tyson?

  I've never thought deeply about that fact. I just thought it'd just be more entertaining, but it's more bonding.

• 37:01Speaker 02

  What it means is that you share a lot of, uh, common ground, common knowledge. That is, you can't get the joke unless there's some hidden unstated premise that makes it work. Uh, and that, that can, uh, bond people. It can also be a devastating put-down, and an intolerable insult. I give the, the famous example of the roast at the National Press Correspondence Dinner in, uh, during the Obama presidency, where Donald Trump was in the audience, and Obama made a number of jokes at Trump's expense. Ordinarily, people are expected to be a good sport and to accept the barbs, showing that they have commonality, common ground with everyone in the room. But Trump...

• 37:43Speaker 02

  Took it personally, he was visibly fuming and scowling at a joke like, "Well, it'd be good if Donald Trump was president because he could accomplish things like closing Guantanamo, because he has a history of running waterfront real estate into the ground."

• 37:56Chuck Nice?

  That's a great joke.

• 37:58Speaker 02

  Trump didn't think so.

• 38:00Chuck Nice?

  No. It's a terrible joke.

• 38:03Speaker 02

  So the point is that everyone who laughed, first of all, knew that Trump, despite his boasts of being a business genius, had a string of failures, which made it all the more painful for Trump for that to be brought out into the open. According to some stories, that's what led him-

• 38:19Neil deGrasse Tyson?

  To run in the first place.

• 38:20Speaker 02

  Yeah, for revenge.

• 38:22Chuck Nice?

  And they're all now being investigated by my Justice Department. It was a hoax, Obama and his jokes.

• 38:29Speaker 01

  So what happens when the humorist just twists the common knowledge? And I think you've got, you touched this in the book, toilet paper shortage.

• 38:41Speaker 02

  Oh, yes.

• 38:42Speaker 01

  And the origin of that story.

• 38:43Speaker 02

  So there's some viral fads and phenomena which can be really significant.

• 38:47Speaker 01

  So common knowledge is a kind of virulent property?

• 38:50Speaker 02

  It can be, yes, exactly. So in the case of, say, a bank run, where a rumor starts that the bank might be in trouble, now, of course, banks don't have enough cash on hand-

• 39:01Chuck Nice?

  Ever.

• 39:02Speaker 02

  ...to redeem all their deposits.

• 39:03Chuck Nice?

  Right.

• 39:04Speaker 02

  But if you worry that other people worry, that still other people worry, that other people worry that the bank might be insolvent, then everyone rushes to the bank to withdraw their savings, which can actually cause the bank to fail, even if it was sound. And that can bring down an entire economy. That was in part the cause of the Great Depression. And so when Roosevelt said, "The only thing we have to fear is fear itself," this was a theorem of common knowledge. It wasn't just a feel-good bromide, but he was accurately diagnosing the situation, which is why financial leaders-

• 39:35Neil deGrasse Tyson?

  That was a, that's Roosevelt speaking to flat-earthers. The only thing we have to fear is fear itself.

• 39:40Chuck Nice?

  Oh my god. How long have you been waiting for that? Oh my god. No.

• 39:45Neil deGrasse Tyson?

  That's a good one. Is fear itself.

• 39:49Chuck Nice?

  It's so bad, I'm laughing at it.

• 39:50Neil deGrasse Tyson?

  It's good.

• 39:51Chuck Nice?

  Oh dear, it's totally good. You got your dad joke out, haven't you?

• 39:54Neil deGrasse Tyson?

  I know, that was a dad joke. And of course, the run on the bank.

• 39:57Chuck Nice?

  It got me though, I gotta say.

• 39:59Neil deGrasse Tyson?

  The run on the bank in Mary Poppins was caused by a little child.

• 40:01Chuck Nice?

  Yes.

• 40:02Neil deGrasse Tyson?

  Where they took his coin, he had some kind of pence or something.

• 40:05Chuck Nice?

  A shilling.

• 40:06Neil deGrasse Tyson?

  Yeah, to start an account, but the boy didn't want him to do that. He said, "Give me back my money." And then this permeated the halls of the theatre.

• 40:15Chuck Nice?

  Two older ladies overhearing the conversation.

• 40:17Neil deGrasse Tyson?

  They overhear, they're not giving him his money. "I want my money." And then there was a run on the bank.

• 40:21Chuck Nice?

  That's so funny, that's great.

• 40:23Speaker 02

  So, once again, something that is public can then set off cycles of thinking about what other people are thinking about, what other people are thinking about.

• 40:32Neil deGrasse Tyson?

  That's the virulence you're talking about, because it just fires through.

• 40:35Speaker 02

  And a similar phenomenon might be why there was a toilet paper shortage during the Covid pandemic. It actually wasn't a toilet paper shortage until people thought there was this toilet paper shortage, so they hoarded because they thought other people were hoarding. When stores started posting maximum three rolls per customer, that didn't so much throttle the demand as it reassured everyone.

• 40:57Chuck Nice?

  That there was a shortage.

• 40:58Speaker 02

  Well, that other people wouldn't be able to strip the shelves bare, so they didn't have to worry about stripping the shelves bare. "I only need three rolls, but I'm only gonna ask for three rolls because none of the other people can buy more than three rolls either."

• 41:11Chuck Nice?

  Right.

• 41:11Speaker 02

  And so that kind of.

• 41:13Chuck Nice?

  It's a level setter. So who was the originator of this? By the way, I still have toilet paper from the pandemic. Hate to admit it.

• 41:20Speaker 02

  According to one story, it came from a big common knowledge generator in the day, namely Johnny Carson on The Tonight Show. So in the old era of three networks, Johnny Carson was the king of late night. He hosted The Tonight Show for many decades. When you were watching it, you had a good reason to think that the rest of the country was watching it and knew that the rest of the country was watching it. In the early 70s, after the oil embargo, when there was an oil shortage. He made the joke one night, you know, we have shortages of everything these days. There's a shortage of gasoline, there's a shortage of meat, there's a shortage of coffee. But you hear the latest, I read in the papers, there's a shortage of toilet paper. Now, it turns out, there wasn't a shortage of toilet paper.

• 42:01Neil deGrasse Tyson?

  It was just a joke.

• 42:01Speaker 02

  But as soon as he made the joke, there was a shortage of toilet paper, as everyone started to hoard toilet paper.

• 42:05Neil deGrasse Tyson?

  So fulfilling.

• 42:06Speaker 02

  And according to at least one theory, ever since then, whenever there is a hurricane or a blizzard, people think that toilet paper is the thing you gotta stock up on, because everyone else is gonna...

• 42:17Neil deGrasse Tyson?

  There was an episode of Curb Your Enthusiasm, where someone was revealed to have an entire closet full of toilet paper.

• 42:23Speaker 02

  Oh, yes, during the pandemic.

• 42:24Neil deGrasse Tyson?

  Yeah.

• 42:25Speaker 02

  That's right.

• 42:25Neil deGrasse Tyson?

  Entire closet. But how much ass wiping do you think you need to do? How big is your ass?

• 42:31Chuck Nice?

  By the way, in a hurricane, when your home floods, that toilet paper's not gonna be worth anything.

• 42:36Neil deGrasse Tyson?

  Yeah, wet toilet paper.

• 42:37Chuck Nice?

  Wet toilet paper really isn't so much fun, I'm saying.

• 42:39Speaker 02

  Well, in the other direction, you can also get speculative bubbles. You buy crypto because you think other people are buying crypto, or at least will wanna buy crypto tomorrow, so they'll pay for more for it tomorrow than you paid today.

• 42:50Chuck Nice?

  Right.

• 42:50Speaker 02

  And they're buying it tomorrow, because I think they'll sell it to someone who wants to buy it the day after tomorrow.

• 42:54Neil deGrasse Tyson?

  The hot potato.

• 42:55Speaker 02

  The hot potato, yes, or the greater fool.

• 42:58Neil deGrasse Tyson?

  The greater fool.

• 42:59Speaker 02

  And that goes back to John Maynard Keynes, who in the 1920s compared speculative investing. So this is investing not because of the return that you expect on the asset, that is, the profits that the manufacturer will make selling widgets, or the farmer selling food, but you think you can unload the security at a profit on someone else.

• 43:20Chuck Nice?

  Right.

• 43:20Speaker 02

  And he said, "It's like a beauty contest, where instead of picking the prettiest face, the object is to pick the face that the most other people pick, where they're picking the face with the same goal, that is, trying to figure out what everyone else is picking."

• 43:33Chuck Nice?

  Wow.

• 43:34Speaker 02

  So it's sometimes called a Keynesian beauty contest.

• 43:36Speaker 01

  Don't we have that in primaries, with elections?

• 43:39Speaker 02

  And in elections, are Keynesian beauty contests. That is, in a primary election, there may be a field of a dozen candidates. And no one wants to waste their vote in just deciding who's going to come in at seventh place as opposed to eighth place.

• 43:52Neil deGrasse Tyson?

  Which is what ranked choice voting is trying to resolve.

• 43:54Speaker 02

  That's why, yes, that's exactly what it's trying to resolve. And so people are hyper aware for any signs that someone has momentum, that they're in the lead, because they want to vote to determine who comes in first, not who comes in sixth.

• 44:05Chuck Nice?

  Right, I don't want to waste a vote.

• 44:06Speaker 02

  I don't want to waste a vote. And so during the coverage, any various trivial gaffes and lapses or boosts can sometimes shoot a candidate to the top or sink their candidacy. Like when a few years ago when Howard Dean was running for president. And that, and everyone knew, you can't vote for Dean now because his victory scream means that everyone knew that he had a silly victory scream. And that injured his candidacy.

• 44:34Chuck Nice?

  Can you imagine?

• 44:35Speaker 02

  Seriously?

• 44:36Chuck Nice?

  No, I'm, yes.

• 44:37Neil deGrasse Tyson?

  Don't make fun of us.

• 44:38Speaker 02

  No, no, no, no, no.

• 44:39Neil deGrasse Tyson?

  You have some weird politics yourself.

• 44:41Chuck Nice?

  By the way, a highly qualified candidate who was not able to continue his candidacy because he was like, "And then we're gonna go to New Hampshire, and then we're gonna go to Vermont, and then we're gonna go to..." And he did that, and everybody was like, "Oh dude, you can't be president, not like acting like that." And then years later, we're just like, "You know, you can grab him by, you can grab him by the whatever. You can just grab him anywhere you want." And they sometimes let you do it because of fame. And we're like, "Yeah, that's the guy. That's the guy right there. We gotta let that guy..."

• 45:15Speaker 02

  The Trump phenomenon is interesting because what he did, is done repeatedly, is that he has flouted norms that everyone thought were inviolable. They were inviolable only because people thought they were inviolable. And they existed as common expectation, common knowledge, and as soon as he flouted them and did not pay the price, they no longer existed as norms, which is why they're, I think, being copied by people like Elon Musk, also a troll, liar, a braggart, that, things that would be unthinkable for a president, for a CEO, as soon as they're thinkable, they're thinkable.

• 45:51Speaker 01

  So is this, is this the fracturing of common knowledge that is partly behind the polarity of society right now, where people are just refusing and disinterested mainly to find a common ground?

• 46:04Speaker 02

  Yeah, so common knowledge is always is defined relative to a network of sharing of information. It could be two people, in some of the examples we've discussed, it could be the entire country. And there has been a segregation into two separate pools of common knowledge. Everyone blames social media, that probably has something to do with it.

• 46:23Neil deGrasse Tyson?

  Yeah.

• 46:23Speaker 02

  But I think it's also cable news, Fox News, prior to social media had that effect. You weren't watching Walter Cronkite at the same time as everyone else was watching Walter Cronkite or Johnny Carson. And residential segregation. When you had educated people flocking to cities, leaving behind the less educated. When you had a decline in organizations that brought people together across the socioeconomic divides, like the army in the era of the draft, like churches, like service organizations, like, you know, the Lions Club, like bowling clubs. You stopped rubbing shoulders with people from different social classes. Each one then hung out with people like them, and then the common knowledge that they shared

• 47:08Speaker 02

  started to grow disjoint.

• 47:10Neil deGrasse Tyson?

  Yeah, so it feeds divisiveness. Because, I mean, it's the same issue, as you said, multiculturally, right? Except now it's within the same culture, but now people are dividing with the same motive.

• 47:23Speaker 02

  Different cultures within the same country.

• 47:26Neil deGrasse Tyson?

  Within the same country.

• 47:27Speaker 02

  Yeah.

• 47:27Chuck Nice?

  That makes me feel like it's exacerbated by what I'll call the vituperative disposition of leadership right now.

• 47:36Neil deGrasse Tyson?

  I don't know what that word means, I'm sorry. What does that word mean? Vituperative?

• 47:41Chuck Nice?

  Vituperative, it means like...

• 47:42Neil deGrasse Tyson?

  It's very SAT.

• 47:43Chuck Nice?

  Is it?

• 47:45Chuck Nice?

  It means like mean and nasty, like a diaper. So when we're siloed into these different camps like this, it becomes very easy then to point fingers and say, "That's your enemy, that's your enemy, that's your enemy." And then it's okay to be mean and nasty towards those people. And it seems like that's exactly where we are.

• 48:07Neil deGrasse Tyson?

  Nazi Germany took that all the way through.

• 48:10Chuck Nice?

  I wasn't even thinking along those lines, but absolutely, yes, that's how it went down.

• 48:13Speaker 02

  But yeah, norms of civility, things you just don't say, you don't, you might disagree with someone, you might even, you know, not think highly of them, but you don't insult them to their face. I mean, you do on the playground, but there was a norm in politics, in corporations, in the media, that you, you pretend that you like them even if you don't. And that's, those are some of the norms that are, that are shattered. You don't lie blatantly. Now, everyone lies somewhat, just, I always probably tell two lies a day. But you don't blatantly lie, you don't show a contempt for the truth, you at least try to pretend that you're, you're honest.

• 48:45Neil deGrasse Tyson?

  Can I give you an example? So I befriended a, I have a sort of Republican confidant, who was in Congress for like 25 years.

• 48:51Chuck Nice?

  You can tell them that it's me, Neil.

• 48:56Neil deGrasse Tyson?

  He was in through Reagan and beyond. And then I, I was talking to Al Gore, and I was saying, I, I was friends with this guy, but I had to work it because we come from different places. And you know what he said? He didn't say anything bad, he just said, "Yeah, he's an acquired taste."

• 49:16Neil deGrasse Tyson?

  That was, that was pretty politic.

• 49:18Chuck Nice?

  That is a very politic.

• 49:20Neil deGrasse Tyson?

  Right. He didn't insult, he just said, you know, "You gotta, you gotta work it." And then, as any acquired taste would be. So that's an example. You don't hear that today.

• 49:28Speaker 02

  Yeah, or like when Winston Churchill was asked, "Maybe the reason you lost the election to Clement Attlee is that people thought that Attlee was more modest." He said, "Well, Mr. Attlee has much to be modest about."

• 49:41Chuck Nice?

  He did have a good turn of phrase.

• 49:44Speaker 01

  Let me ask you before we have to, to wrap this up.

• 49:46Neil deGrasse Tyson?

  Yeah, we gotta start wrapping.

• 49:47Speaker 01

  What plays out if society remains unchecked? Where the common knowledge is distorted, or the common knowledge is dictated by the loudest voice, no matter what that voice is saying?

• 50:01Neil deGrasse Tyson?

  Yeah, by nefarious forces.

• 50:02Speaker 01

  Yeah.

• 50:03Neil deGrasse Tyson?

  Influencing.

• 50:03Speaker 02

  Yeah, well, we're seeing some of it, we're seeing the polarization, particularly the negative polarization, that is not just disagreeing, but thinking that the other side is stupid or evil. I don't have an algorithm for reversing that, but the kind of norms that we should spread would be ones of... Civil disagreement, epistemic humility, charity, things that go against human nature, where we tend to think of argument as a competition, as a war. I attacked his arguments, he defended them, but then I demolished them. We use the metaphors of war in talking about argument. And in one of the chapters, I talk about a different model for argument, coming out

• 50:44Speaker 02

  of a mathematical theorem, claiming that we rational agents should not agree to disagree.

• 50:49Neil deGrasse Tyson?

  That's how I feel, by the way.

• 50:51Speaker 02

  Well, there's actually some, it's a proof by the Israeli mathematician Robert Alman that depends on common knowledge. We don't have time to go through it now, but it does set a kind of an alternative paradigm for argument, that instead of two people beating each other up and the one left standing wins, that's not how you discover the truth. Or even bargaining and negotiating and you come to some compromise. You think about, why should the truth just happen to lie halfway in between two opinionated guys? But rather, it's kind of a random walk, where when two people exchange information, they might go all over the map until they converge on a common conclusion.

• 51:33Neil deGrasse Tyson?

  That's precisely how I feel. I mean, otherwise you just- Well, you would as a scientist. Yes. That is kind of like your whole field. If we disagree, it's because there's insufficient data- Right. -to create the agreement, so now let's go have a beer. Right. And invent the experiment that will resolve this- There you have it, yeah.

• 51:52Speaker 02

  So that would be the kind of norm, it goes against human nature. I think the progress-

• 51:57Neil deGrasse Tyson?

  Clearly.

• 51:58Speaker 02

  The progress of science shows it's the best way to do things. And even, of course, scientists are not immune to pissing contests, dominance contests, and that's, you know, at least we acknowledge it's a bad thing. For that norm to spread in journalism, in politics, in the court system would be- Would be a good thing.

• 52:15Neil deGrasse Tyson?

  It would be transformative.

• 52:15Speaker 02

  Yes. More, more, more truth, less vituperation.

• 52:18Neil deGrasse Tyson?

  Once again, science saves the day. Science! And he said vituperation. He's, he doubled down on it. There it is. I see what he did there. Yeah, I think we gotta call it quits there.

• 52:29Speaker 02

  Oh, my God.

• 52:30Neil deGrasse Tyson?

  That's a great conversation, man. Let me see if I can take us out with a quick cosmic perspective. With your permission.

• 52:36Speaker 02

  If you're feeling it, do it, my man.

• 52:37Neil deGrasse Tyson?

  Yeah. Yeah. I spent my life studying the universe, which is a huge, complex place. All the laws of physics I learned in physics class are applied in some place, in some way, at some time, in the unfolding universe. Also, the laws of chemistry and our search for life in the universe. There's the biology that we bring with us. All of this. And every time I reflect on that, I think to myself, this is not the hardest thing we can think about out there. You know what the hardest thing is? The human mind. What's going on inside there? And we've got psychologists, neuroscientists, it's a whole field, trying to figure ourselves

• 53:22Neil deGrasse Tyson?

  out. And, you know, I'm glad I do something as easy as astrophysics, relative to what they've gotta worry about. And I just hope that the study of the human mind by the human mind is not the most complex thing we ever have to tackle in this universe. But if it is, get ready for that ride, because the human mind is not logical, it's not rational, only occasionally. It was not only the source of everything we value and call civilization, it may actually be the end of it as well, if we're not careful. And that's a cosmic perspective.

• 54:07Neil deGrasse Tyson?

  Stephen, thanks for joining us.

• 54:09Speaker 02

  Thank you so much.

• 54:10Neil deGrasse Tyson?

  All right.

• 54:10Speaker 02

  It's been a great pleasure.

• 54:11Neil deGrasse Tyson?

  Stephen Pinker's latest book? Give me the title again?

• 54:14Speaker 02

  When Everyone Knows That Everyone Knows... Dot, dot, dot.

• 54:17Neil deGrasse Tyson?

  You got it. There you go. Chuck? Always a pleasure. All right, Gary. Pleasure, my friend. This has been StarTalk, special edition. Neil deGrasse Tyson, your personal astrophysicist, as always. Keep looking up.