Science You Believe That Isn't True & The Story of The Lie Detector - SYSK Choice

This may be hard to imagine but trees can fight crime. Not all types of crime but they the fight some crime – and no one really knows how they do it. Listen to hear the explanation. https://www.motherjones.com/environment/2019/04/trees-crime-cincinnati-philadelphia-ida-b-wells-chicago/ People believe things like goldfish have a 3-second memory. Or that lightning never strikes twice in the same place. And I bet you believe that water is a good conductor of electricity. None of these things are true. They are examples of the many science myths that a lot of people believe. In this episode, we are going to debunk these and others with my guest, science writer Brian Clegg. Brian is the author of over 40 books, one of which is titled Lightning Often Strikes Twice: The 50 Biggest Misconceptions in Science (https://amzn.to/41sY3jK) I’m sure you’ve seen a polygraph machine in movies or on TV. This device can supposedly tell if someone is lying. But does it actually work? If it is so reliable, why do most courts refuse to allow the results of polygraph tests as evidence? Yet, if it is unreliable, why is it still being used? The story of the polygraph or lie detector is fascinating. Here to tell it is Amit Katwala an award winning journalist, a senior writer at Wired and author of the book Tremors in the Blood: Murder, Obsession, and the Birth of the Lie Detector (https://amzn.to/3Zngu7C) Are men better drivers than women? It really depends on your definition of “better.” However, in terms of accidents, moving violations and parking ability, there is a difference between men and women. Listen and I’ll reveal which gender scores better. https://www.nytimes.com/2020/04/27/well/live/car-accidents-deaths-men-women.html PLEASE SUPPORT OUR SPONSORS!!! FACTOR: Eat smart with Factor! Get 50% off at https://FactorMeals.com/something50off QUINCE: Indulge in affordable luxury! Go to https://Quince.com/sysk for free shipping on your order and 365-day returns. TIMELINE: Get 10% off your order of Mitopure! Go to https://Timeline.com/SOMETHING SHOPIFY: Nobody does selling better than Shopify! Sign up for a $1 per-month trial period at https://Shopify.com/sysk and upgrade your selling today! HERS: Hers is changing women's healthcare by providing access to GLP-1 weekly injections with the same active ingredient as Ozempic and Wegovy, as well as oral medication kits. Start your free online visit today at https://forhers.com/sysk INDEED: Get a $75 sponsored job credit to get your jobs more visibility at https://Indeed.com/SOMETHING right now! Learn more about your ad choices. Visit megaphone.fm/adchoices

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

• 0:00Mike Carruthers?

  Gifts mean more when they have the power to give more. They can inspire more discovery, give more confidence, and unwrap more of who you are. This Black Friday, give a gift that goes beyond the box. The Dell XPS 13 laptop. With a beautiful design and cutting-edge performance, it helps you unlock more possibilities. It's the thinnest, lightest XPS laptop yet, with touchscreen, a backlit keyboard, and long-lasting battery life to power you through your day. Built with a durable aluminum chassis, weighing just 2.2 pounds, and Intel Core processors,

• 0:42Mike Carruthers?

  it's fast, reliable, and portable enough to keep up wherever you go. Visit dell.com to explore the possibilities with XPS. While shopping, you'll also find great perks like Dell Rewards, fast, free shipping, premium support, and financing with flexible payment options. Plus, you can find great deals on monitors and accessories. That means you can score a whole new setup now for less. This Black Friday sale is one you don't want to miss. Head to dell.com/deals. That's dell.com/deals.

• 1:28Mike Carruthers?

  Today on Something You Should Know, how is it that trees fight crime? Then, science myths that many people believe, like sugar makes kids hyper, water is a good conductor of electricity, and lightning never strikes the same place twice.

• 1:44Speaker 01

  The classic is the Empire State Building. It's typically struck, I think, about 25 times a year. In fact, there's even one guy, there was a US park ranger called Roy Sullivan, who's been struck by lightning seven times in his career, thankfully survived it all.

• 1:59Mike Carruthers?

  Also, are men better drivers than women? And the polygraph, or lie detector? Where did it come from? How does it work? And does it work?

• 2:08Speaker 02

  Essentially, the reason the polygraph has been so successful is because of the theater around it, right? It works because people believe it works, so that the mere threat of being attached to a polygraph can compel someone to confess to the crime before the exam even takes place.

• 2:22Mike Carruthers?

  All this today on Something You Should Know.

• 2:27Mike Carruthers?

  I imagine most of us shop for clothes online, at least some of the time. And there's always that little mystery. Is what shows up at your door actually going to look like what you think you ordered? We've all had that experience. I know my wife has ordered dresses that look beautiful in the pictures. But when they arrived, eh, not so beautiful. Cheap-looking, disappointing. And that's one of the reasons we've become such big fans of Quince. When we order from Quince, we are confident we're going to get something really nice. The quality is consistently good, and the prices are surprisingly reasonable.

• 3:07Mike Carruthers?

  I've bought their cashmere sweaters, which are gorgeous, and they start at just $60 for cashmere. My wife buys tons of stuff from Quince, and we keep coming back. Quince works directly with ethical factories and cuts out the middlemen, offering prices 50% to 80% less than similar brands. And with the holidays coming, that's a pretty compelling combination. Beautiful clothes and gifts without spending a fortune or wondering what's really going to show up at the door. I really do recommend Quince. It's one of those companies that has earned our trust. Give the gift of quality this holiday season. Download the Quince app for app-exclusive offers, or go to quince.com.

• 3:52Mike Carruthers?

  Get free shipping on your order and 365-day returns. Now available in Canada and the UK, too. And when Quince asks where you heard about them, please let them know it was something you should know. It's the best way to support the show.

• 4:23Mike Carruthers?

  Hi, welcome and thank you for joining me for another episode of Something You Should Know. And we're gonna start today talking about trees. If you live in a neighborhood that has a lot of nice, big trees, it's a little safer than neighborhoods without them. According to the U.S. Forest Service, "Less crime occurs in neighborhoods with big trees in the front yards and along the street." So what exactly makes having trees a deterrent to crime? Well, for the most part, it's an unexplained phenomenon, but researchers have come up with a few ideas. Some say trees signal that the area is well-cared-for, similar to the "broken windows" theory, which suggests that disorder invites crime.

• 5:09Mike Carruthers?

  Some say green spaces make an area inviting and can lead to more informal surveillance. Other theories point to the well-documented calming effect of vegetation and nature, or that the idea that greenery promotes trust in the community. Whatever the reason, trees fight crime. And that is something you should know.

• 5:35Mike Carruthers?

  I'm sure you've heard statements, scientifically kind of statements, like "lightning never strikes the same place twice", or "your blood is red because of the iron in it", or that "the Big Bang Theory explains the beginning of the universe". But these are actually examples of statements that are not true. And there are a lot of them. Things that you may believe that just aren't so. And here to reveal several of them and explain why they're not true is Brian Clegg. Brian is a science writer and speaker who has written over 40 science books. One of them is called "Lightning Often Strikes Twice: The 50 Biggest Misconceptions in Science".

• 6:20Mike Carruthers?

  Hi, Brian. Welcome to Something You Should Know. Thanks for having me. So what made you decide to tackle this, to try to explain that a lot of things that we perhaps believe about science are in fact not true?

• 6:33Speaker 01

  I spend a lot of time talking to people about science on and also often what comes up is it's a bit more complicated than we thought that science tends to be a little more complicated than we think about it. And what I'm looking at here in a fairly lightweight, a fairly fun way is areas where we think that science is different from the way it really is, or where we simplify it so much that actually we don't really understand what's happening. So it's just trying to open up a little bit. It might be urban myths, it might be folklore, or it might just be not quite getting the science right. And what I hope is an enjoyable way.

• 7:13Mike Carruthers?

  Well, let's get specific. And one that you talk about that I have always believed is that water is a very good conductor of electricity. And you know, you see in the movies that somebody throws a toaster that's plugged in into a bathtub to kill somebody. Or to me, I've always thought water was a very good conductor of electricity.

• 7:35Speaker 01

  And it seems crazy to say water doesn't conduct electricity, but actually it's a really bad conductor of electricity. But what is happening is it's the impurities in the water that enable it to do that conducting. So if you take totally pure water, it's a really bad conductor. And sometimes there's little things like that, or for that matter, toast, toast falling butter side down. You know, this thing, you drop a slice of toast, it falls on the floor. It's always the butter side that hits the floor. Or is it? Can that really be true? And a number of TV shows have actually tried to demonstrate it's not true. But unfortunately, what they've tended to do is toss toast in the air, a bit like

• 8:16Speaker 01

  tossing a coin. But the reality is, when you drop a slice of toast, you don't throw it up in the air like a coin, it slides off your plate, or it slides off the work service. And they're just about the right height, that when something slides off and starts to turn, it has enough time to turn. Half a turn, so the butter side's gone down, but not enough time to go all the way. So it genuinely is true that even though lots of people think, sure, it can't really be true that toast always falls butter side down, it pretty much always does.

• 8:48Mike Carruthers?

  Well, let's go back to the water one because, you know, you're told not to stand in water when you're holding something electric because the water will, that there's something about standing in water that that's gonna kill you. So something's gotta be there other than just the impurities, no?

• 9:07Speaker 01

  No, absolutely not. The actual water, literally pure water, H2O is a bad conductor, it's a good insulator. But the fact is, almost all the water we deal with on a day-to-day basis, the water that comes out of faucets in the bathroom, is water that has minerals in it. And that's a good thing, you know, on the whole, there's nothing wrong with that, it's not a problem. But these minerals are in the form of what are called ions, so they're basically positively electrically charged, negatively electrically charged. And that means that they can carry an electrical current. And it's those impurities in the water that actually carry the current. And it is dangerous, of course. Yes, you don't wanna play around with electrics when you're in contact with water, because on the whole,

• 9:52Speaker 01

  the water we experience isn't pure.

• 9:54Mike Carruthers?

  So since it's the title of your book, does lightning strike twice?

• 9:59Speaker 01

  Yep, it certainly does. I think one of the reasons for this is, you know, lightning's probably the most dramatic natural occurrence that most people have experienced. You know, there are bigger things out there, more horrific things like earthquakes and so forth. But the fact is, most people have experienced lightning, it's pretty frightening stuff if it's fairly close. And if you ever see an actual lightning strike, or it hits a tree or something like that, it's very dramatic. And certainly, you know, over the centuries, most people would not have seen lightning strike in the same place twice. And because of that, a kind of folklore built up around it. But the fact is, it does happen, and it happens a lot. You know, any one time around the world, there may be 20,000 lightning

• 10:42Speaker 01

  storms, thunderstorms happening. And somewhere where there's a nice big pointy thing, you will get more than one strike. So the classic is the Empire State Building. It's typically struck, I think, about 25 times a year, and it has been struck as many as 15 times just in a single storm. The fact is, lightning really does strike more than once on the same location. But it this kind of it's it's almost become a, you know, way of referring to something. So we don't necessarily literally mean lightning doesn't strike twice, but rather more metaphorically, it's not likely to happen. In fact, there's even one guy, there was a US park ranger called Roy Sullivan,

• 11:25Speaker 01

  who's been struck by lightning seven times in his career, thankfully survived them all.

• 11:31Mike Carruthers?

  He's either really lucky or really unlucky. I mean, and just in terms of the odds, that seems like like he he must have to be trying to be struck by lightning because nobody can that just seems impossible.

• 11:47Speaker 01

  I'm not sure he's still with us, but when he was around.

• 11:50Mike Carruthers?

  I'm not surprised if he isn't.

• 11:53Speaker 01

  The kind of job he was doing, he was out there out in the wilds a lot, out in places where you may possibly get struck by lightning more than most of us are.

• 12:03Mike Carruthers?

  One of the fun ones, because I've always wondered how you would ever know this, is that a goldfish has a three second memory. How would you ever test that in the first place?

• 12:14Speaker 01

  Anybody who actually owns fish, particularly if you have a pond, knows instinctively almost that this isn't right, because the fact is, goldfish learn, for instance, that, you know, if you come to the edge of a pond in a particular place, holding something and sort of shaking it around, food's coming and they come to you, remember it, they do have a memory. But in science, scientific terms, it's been tested by training them, for instance, to go through mazes and they remember how to do that. In fact, all the evidence is that the original three second memory bit came from a commercial, an advertisement that was done just humorously referring to this and somehow it's become part of what we tend to believe.

• 12:59Speaker 01

  And it's it's handy for a joke, it's, you know, but it's not really something.

• 13:04Mike Carruthers?

  Of all the things you talk about, if any one of them has crept into conventional wisdom more than any other, is the idea that sugar makes kids hyper. I mean, so many people believe that because it's their experience, that they see it, they kids have sugar and they seem to get hyper. So how can that not be true?

• 13:27Speaker 01

  It's a problem that you get in a lot of um scientific experiments, actually, not just the anecdotes, because if somebody's just reporting, say, how they feel or what's happened, we can't actually isolate what the cause is. Now, what you actually find in practice is that when people have said, oh, yeah, the kids have got really excited, they've had lots of sugar, there is often some other thing going on at the same time. So, you know, you take children to a party, yeah, they get lots of sugar, they get really excited, but also they're at a party, so is it really surprising that they're getting excited? Um, that just is no good scientific evidence, you know, when you treat it scientifically,

• 14:11Speaker 01

  which means you have to separate off all the different influences, put people in a controlled situation so that you can actually separate off what is causing something, there is no good evidence that consumption of sugar actually makes them hyper.

• 14:25Mike Carruthers?

  You claim that the Big Bang Theory does not explain the beginning of the universe, but I thought that's exactly what it did explain, so sort that out for me.

• 14:35Speaker 01

  That that's quite a nice little example of the, it's a bit more complicated than that. The Big Bang Theory is a theory of how the universe grew from practically nothing all the way up to what we have today. And we think that has taken about thirteen point eight billion years for it to go from a very tiny, practically nothing, up to what we have now. And the Big Bang Theory is very successful at explaining that, but we tend to kind of associate it with literally the beginning of everything. And that's the one thing the Big Bang Theory doesn't do for us, it doesn't actually explain why or how the universe came into being initially.

• 15:20Speaker 01

  That very first start, it has to already have, if you like, the laws of physics have to be there already. It doesn't explain where they come from. And the actual initial start of the whole thing requires, if you like, it to be there already for it to then start expanding. So it's not quite made it. And the other thing about it is we have a problem just seeing back that far. Now, the universe is really quite generous to us because light takes a long time to get to us from very distant places. So the further out you look in the universe, the further back you see in time. And we can see back until maybe three, three hundred, four hundred thousand years after the beginning.

• 16:03Speaker 01

  But beyond that, we can't see because the universe wasn't transparent before then. Light couldn't get through it. So what it does mean is that those first years, we struggled a little bit to be sure exactly what happened then. And certainly, the Big Bang doesn't give us any insights of the initial beginning. So it's just a slight tweak, if you like. It's a great theory. It explains a lot. It gives us a timescale for the universe, but what it doesn't do is say how the universe came into being.

• 16:32Mike Carruthers?

  We're talking about science myths, things that a lot of people believe that just, just don't happen to be true. My guest is Brian Clegg. He is author of the book, Lightning Often Strikes Twice: The Fifty Biggest Misconceptions in Science. If you listen to something you should know regularly, you know we talk about sleep quite a bit here. And one of the things I've learned from those conversations is just how important a good night's sleep is. And I've always been someone who loves his sleep. So I was intrigued when I heard about Beam Dream. It's a delicious nighttime drink formulated to help you fall asleep faster, stay asleep, and wake up refreshed.

• 17:15Mike Carruthers?

  It contains ingredients like reishi, magnesium, L-theanine, epigenin, and melatonin. They have lots of great flavors. I tried the cinnamon cocoa flavor, and I love the idea of having something warm and delicious as part of winding down at night. And it's less than 20 calories per serving. Dream has improved more than 30 million nights of sleep, and they back it up with a 30-day money-back guarantee. If you don't sleep better, you get your money back. And right now, there's a terrific offer. Go to shopbeam.com/sysk, use code S Y S K, and get 50% off during Beam's cyber sale.

• 17:59Mike Carruthers?

  Only available while flavors are in stock. With this incredible discount, that means you'll pay just 83 cents per night for the best sleep of your life. So seriously, think about it. I mean, how much would you pay for a truly great night of sleep? Beam is just 83 cents per night. So go to shopbeam.com/sysk now. That's shopbeam.com/sysk. This episode is sponsored by Vinted. You know, I remember interviewing an organizing expert who offered this really clever trick for figuring out which clothes you should get rid of. You go to your closet and you look at the clothes hanging there.

• 18:42Mike Carruthers?

  And chances are, the ones toward the middle are the clothes you wear most often. But the clothes pushed way over to the left or the right, some of those you probably haven't worn in years. And yet there they hang, taking up space. But here's the thing. You could turn those clothes into money. That's where Vinted comes in. Vinted is a secondhand marketplace app where you can sell clothes you no longer wear and make some extra money. Listing on Vinted is so quick and simple. And when something sells, Vinted creates a prepaid shipping label for you. And here's what I really like. Vinted charges no seller fees. So whatever you earn from selling your clothes, you keep.

• 19:27Mike Carruthers?

  Think about that. Clothes that you aren't wearing, taking up space, could be putting money back in your pocket. So here's my suggestion. Take five minutes, go look at the far ends of your closet and see what's hanging there. You might be surprised. Download the Vinted app for free and start listing. With no seller fees, you keep every dollar you earn. That's Vinted, V-I-N-T-E-D. So Brian, what about blood? People say that the reason your blood is red is because it has iron in it and iron makes it give it that red color. But you say that's not true.

• 20:08Speaker 01

  Blood is red because of hemoglobin, so there's substance in the stuff that carries the oxygen around the body. And that hemoglobin does contain iron. And so it's quite easy to get a little bit confused and think, okay, well, iron usually makes things reddish, you know, so rust is iron oxide, it's an iron compound. Mars looks red because there's a lot of iron in the surface. So we tend to associate iron and redness. But it happens, the reason hemoglobin is red is actually due to the shape of the molecule, the way it interacts with light, it's nothing to do with the fact the iron's in there. So that's one aspect of it, it's not actually caused by the iron.

• 20:53Speaker 01

  And the other thing is the blue blood thing is not about the color of the blood itself, it's about the way that light interacts with your veins. It's quite separate from the color of the blood in them. Color's quite interesting, you know, sometimes it's caused by a pigment, so sometimes it's caused by the color of stuff, but sometimes it's structural. So actually, the shape of something can change the appearance or the way light interacts with molecules. You know, if you look up at the sky, the sky's blue, but there's no blue pigment in the sky, there's nothing up there that is blue. It's literally the way the light is interacting with the molecules of air.

• 21:36Speaker 01

  And similarly, when you see the blue veins in your arm, it's not that the blood in them is blue, it's the way the light interacts with the material that makes up the veins.

• 21:46Mike Carruthers?

  Something I've heard, and I think a lot of people have heard this in one form or another, that you can't explain how a bee flies, that a bee flies in defiance of the laws of physics, it's just impossible to explain, it's a mystery. And you say it's not a mystery.

• 22:06Speaker 01

  The reality is that bumblebees don't fly the way you might think. So, you know, if you think of a bird flapping its wings, it's fairly obvious what's happening. It's flapping its wings up and down, that pushes the air down, effectively pushes the air, the bird up as it pushes the air down. Bumblebee's wings move in a much more complicated way. They basically almost act a bit like a helicopter in that they have a kind of curved motion. And the result of that is they actually generate more lift than you would expect from those little wings. The other thing about bumblebees actually is they look chunky, you know, compared with an ordinary insect, they look pretty fat.

• 22:45Speaker 01

  But actually it's still very light, so it isn't as dramatic looking, as dramatic as it actually looks to be. And the fact is, there's no problem at all with bumblebee wings supporting bumblebees. In some ways, a more interesting example is kangaroos. Because it's genuinely, genuinely true that kangaroos use more energy or appear to use more energy when they bounce along than they consume. They seem to be able to actually give out more energy in their bounces than they've consumed in their food. And the reason for that is it's a bit like the way a rubber ball works.

• 23:28Speaker 01

  You know, if you drop a rubber ball on the floor, it bounces. When I was young, they had these things called superballs, superballs that bounced really high. I don't know if you ever had one of those. And kangaroos are a bit like that. So when they hit the ground, it's not a case of all the energy they're putting into their muscles is wasted. It's actually more like storing up energy in a rubber band as they hit the ground. And then it bounces off and they use up that extra energy they've stored away. So they can do what seem to be amazing things, even though in practice they're not breaking the laws of physics.

• 24:09Mike Carruthers?

  You say that it's a false statement to make that nothing can travel faster than the speed of light. But I've always heard that the speed of light is the absolute limit anything can travel. So I'd like to hear that explanation.

• 24:25Speaker 01

  It's another of those little, it's a little bit more complicated. We're oversimplifying when we say the speed of light is the limit. The real thing is the speed of light in a vacuum is the limit. So the fastest anything can go is the speed that light goes through empty space. But light can also go through other stuff. It can go through water, it can go through glass. And when it does, it slows down. Uh, so light goes considerably slower through water or through glass or another solid transparent substance.

• 25:03Speaker 01

  And when it does that, it's closed down sufficiently that physical objects can move faster than the speed the light's going. And there's something called Cherenkov radiation that happens in nuclear reactors. Have you ever seen a, a video of one of the old nuclear reactors that had water surrounding the nuclear pile? It glows blue. And the reason it's glowing blue is that little particles that are coming off out of the uh, uh, the nuclear reactor are actually going faster through the water than the speed of light through the water. And that produces a kind of optical equivalent of a sonic boom, which produces this blue glow. So yes, it's true. The speed of light in a vacuum is the absolute limit.

• 25:49Speaker 01

  But if we just say the speed of light is as fast as you can go, it's not true if you're not in a vacuum.

• 25:56Mike Carruthers?

  I remember this one, that, that supposedly there were subliminal messages in movies. Like a, a, just a still frame of a, a drink or a snack or something that didn't register consciously with you, but would make you wanna go to the lobby and buy a drink or some popcorn or something. And I remember people talked about that.

• 26:20Speaker 01

  And the fascinating thing about this one is it was, if you like, a deliberate urban myth. So a guy who was in advertising and marketing produced a fake paper effectively saying that this was the case. And he used this to try to sell the idea that these subliminal messages would make people want to drink more of a particular beverage, or want to go out and have a hot dog or whatever. And the fact is, it just wasn't true. There is no good evidence that these subliminal messages work. But the fact is, you know, so many people have heard this, that we still today, in a number of countries, for instance, it's illegal to use subliminal messaging. Interestingly, there are very subtle effects that do seem

• 27:03Speaker 01

  to happen as a result of it. What certainly isn't true is that it will subtly turn people, you know, into the urge to drink a particular drink, or eat a particular substance.

• 27:13Mike Carruthers?

  Well, but there's two questions here. There's, does it work? Which apparently doesn't work very well. But, but also, did it happen? Did, were people putting frames that you could not consciously see in the movie to try to make it work?

• 27:29Speaker 01

  Certainly in the original, no. So it was totally fictional. It was made up, the original, that was written up. It never did happen then. Since then, people have tried it. Either tried it as experiment to see whether or not it works, but also some people have tried to influence others by putting frames in this way. But as I say, all the scientific evidence is that it has very little impact.

• 27:54Mike Carruthers?

  Well, it's fun to trace back the origins of some of these misconceptions. And you also wonder why, why they persist so much. I mean, some of these things have become so ingrained in the kind of collective consciousness, we just accept them on face value, but clearly they're not true. I've been talking with Brian Clegg, and the name of his book is Lightning Often Strikes Twice: The Fifty Biggest Misconceptions in Science. And if you want to read it, there's a link to that book at Amazon in the show notes. Thanks, Brian. Great to have you on.

• 28:27Speaker 01

  Okay, great. Thanks very much.

• 28:29Mike Carruthers?

  Hiring the wrong person is expensive, but it's also exhausting. Because now, you haven't solved your problem, you've created a new one. You've spent time interviewing and training somebody, but it's the wrong person. And it's just not working. So when you're hiring, you don't just need a person, you need the right person. And that is a job for Indeed Sponsored Jobs. Sponsored Jobs helps you reach candidates with the skills and experience and other qualifications you're looking for, and boosts your job and search results, so the right people are more likely to see it.

• 29:11Mike Carruthers?

  In fact, Sponsored Jobs posted directly on Indeed are 95% more likely to report a hire than non-sponsored jobs. So give yourself a better shot at finding the right person. Spend less time searching and more time actually interviewing candidates who check all your boxes. Less stress, less time, more results. When you need the right person to cut through the chaos, this is a job for Indeed Sponsored Jobs. And listeners of this show will get a $75 sponsored job credit to help get your job the premium status it deserves at indeed.com/podcast.

• 29:52Mike Carruthers?

  Just go to indeed.com/podcast right now and support our show by saying you heard about Indeed on this podcast. Indeed.com/podcast. Terms and conditions apply. Need the right hire fast? Then this is a job for Indeed Sponsored Jobs.

• 30:15Mike Carruthers?

  It sure would be great if there was a way to tell if people were lying. In fact, we've talked on this podcast about how to spot a liar by observing people and looking at their behavior. But the fact is, you can never really tell 100%. Some people are just good liars. If only there was a machine. Well, there sort of is. It's called a polygraph, sometimes called a lie detector. You see it in movies and TV shows, and it's supposed to tell if someone is being deceptive. So how does a lie detector or polygraph work? And does it work? After all, the results of a polygraph test are not admissible in most courts.

• 31:00Mike Carruthers?

  So it makes you wonder, how accurate can it be? Well, here to tell the fascinating story of the polygraph is Amit Katwala. He's an award-winning journalist, a senior writer at Wired, and author of the book, Tremors in the Blood: Murder, Obsession, and the Birth of the Lie Detector. Welcome, Amit.

• 31:21Speaker 02

  Thanks for having me, Mike.

• 31:22Mike Carruthers?

  So what is the basic theory of how a polygraph is supposed to work? My understanding is that supposedly, when you lie, because you're lying, there are physical changes, like your heart rate increases and your blood pressure goes up. Things happen because you know you're lying, and that that machine registers those changes, and aha, you're a liar.

• 31:47Speaker 02

  That's the principle or the theory, and we'll get into why that maybe isn't necessarily true later on, I'm sure. But yes, the theory is that if you are doing a polygraph exam, you are going to be scared about getting caught. So when you get asked a question that you know you're going to have to lie on, your pulse will start going up, your blood pressure will go up, you might start breathing differently. And a skilled polygraph examiner, so the theory goes, should be able to tell the difference between someone who's lying and someone who's telling the truth, based on how those things change when they're asked a question.

• 32:19Mike Carruthers?

  And so, so I've always wondered, if you know that, why would you ever agree to be tested?

• 32:29Speaker 02

  It depends on the scenario, I think. A lot of government jobs in the US still require a polygraph exam, so certain military roles, certain police roles, so some people don't have a choice. That was much more rampant until the late kind of 80s, when it was outlawed in commercial enterprises. But there was a brief period when even companies like McDonald's were doing polygraph tests on their, on their potential employees. For criminal cases, you know, I think... Sometimes it's presented as a way for people to clear their name. So I can see why if you are innocent, you might be tempted by that. And maybe if you're guilty, you sort of think, well, you know, I can maybe get away with it.

• 33:04Mike Carruthers?

  It seems such a murky thing because everybody who knows about polygraphs knows that, or at least the legend is, that they're not, the results are not admissible in court. So how accurate could they possibly be if a court is looking for the truth and refuses to use it?

• 33:24Speaker 02

  Exactly. That's a really big kind of flaw in the polygraph. And actually, the polygraph was one of the devices that established the set of standards that we now use to determine whether something is admissible in court or not. It was one of the real test cases where they actually looked at it and they thought, hang on, maybe this isn't really science.

• 33:42Mike Carruthers?

  So where did it start? What was, I mean, it sure would be great to have something you could, you know, make somebody stick their finger in and go, oh, he's lying and be, and be sure that you're right. So where did this all begin? Who thought, hey, I got an idea?

• 33:58Speaker 02

  The polygraph machine specifically, which is, I guess, what most people think of now when they think of a lie detector, has its origins in Berkeley, California in the 1920s with the Berkeley Police Department and a police officer called John Larson. John Larson was a physiologist by training. He wanted to become a criminologist, which is a very new field at that time. And he took a job in Berkeley because Berkeley was, the Berkeley Police Department was led by a kind of visionary police chief called August Volmer. Volmer was one of the first police chiefs in America to try and bring science or evidence to policing. So he gave his officers bikes because he kind of thought that that would enable them to cover more ground. He gave them radios. He started doing crime mapping and all this kind of pioneering stuff.

• 34:41Speaker 02

  And as part of that, he also started to hire college graduates as police officers, which was a real revolutionary step at the, at the time in the kind of 1910s, 1920s. So John Larson was one of these college cops and he, and Volmer came across this paper by a guy called William Marston. He was a psychologist at Harvard University. And he noticed that when he asked his peers to tell untrue stories, their blood pressure went up. So Larson thought, well, okay, that's an interesting insight, but how can I systematize that? How can I turn that into something objective that can be measured and where the measurements can be recorded so that it can be referred back to you later? And it's that insight, you know, how can you take this this thing that we think we've identified where blood pressure goes up when people lie?

• 35:27Speaker 02

  How can we turn that into a machine that is objective rather than just based on a single person's observations? So those are the real seeds of the polygraph.

• 35:34Mike Carruthers?

  When did it start getting used in police work? I mean, I mean, seriously used in police work where, you know, let's hook this guy up to the machine and tell him and figure out whether he's telling the truth or not?

• 35:48Speaker 02

  Funny enough, actually, for the first couple of years, it was mainly let's hook this girl up to the machine rather than this guy. So the first cases were in nineteen twenty one and they were overwhelmingly looking at like dormitory thefts at the University of Berkeley. So that was the first case of the polygraph. It was, um, there was a woman's only dorm in Berkeley and a bunch of stuff had gone missing like jewelry and cash and books and things like that. And this was the first case where the Berkeley Police Department were kind of called in to run polygraph tests on all these young women to try and find out who did it. And so John Larson went along with the machine and he ran tests on all these women, including the woman whose stuff, the woman whose stuff had been stolen to begin with. And, you know, eventually he came across a woman who blew up when the machine was

• 36:31Speaker 02

  connected to her, refused to answer more questions and he kind of thought, well, she's the one who did it.

• 36:36Mike Carruthers?

  How widespread is the use of the polygraph? I mean, is it used a lot or is it, you know, mostly in movies and occasionally, you know, here and there? I mean, how well accepted is it?

• 36:48Speaker 02

  The most recent estimates I have suggest that there are about three million lie detector tests a year in the United States. It's used much more heavily in some countries than others. So the US is a very, very heavy user of the polygraph. Japan is another one. So yes, it was used and it is used, it's still used by government departments, you know, intelligence agencies and things like that. But it's also used by police departments where they want to get a confession from someone without necessarily having to like take a case to trial. It's a much cheaper way of extracting a confession from someone if you think they're guilty than having to go through the sort of expense and process of actually taking them to trial. So it is still used quite widely and you see this in kind of true crime documentaries

• 37:30Speaker 02

  all the time where the polygraph invariably pops up at some point in the investigation. Its heyday was really in the kind of twenties, thirties, forties and fifties, I think. So after Larson did these tests on women in college dorms, then they quickly started, you know, testing suspected murderers and then it kind of snowballed from there with the help of a guy called Leonard Keeler, who was a high school student who really helped to popularise the machine.

• 37:55Mike Carruthers?

  Well, how accurate is it? If you take all the results of a polygraph, I mean, are you ever able to say, well, you know, it's a, you know, fifty fifty, I mean, and if it's fifty fifty, what good is it?

• 38:07Speaker 02

  Yeah, so the estimates range from as high as eighty five to ninety percent to as low as sixty to sixty five percent. So it's not much better than tossing a coin. And studies show that actually, as individuals, we can get it, we can tell when someone's lying about fifty four percent of the time. So it's only slightly better than just human intuition. And I guess this comes to the second point, which is it's not really possible to actually assess how accurate the polygraph is when it comes to criminal investigations, because you never actually know what really happened. Say someone gets found guilty with the polygraph, then gets found guilty by a jury and gets sent to prison. That doesn't necessarily mean they were guilty. So you can never really know. All you can really tell is that in this case, the polygraph agreed with the jury.

• 38:52Speaker 02

  In this case, the polygraph didn't agree with the jury, but juries are fallible as well. So you can never really tell how accurate the polygraph actually is in the real world rather than in lab studies.

• 39:04Mike Carruthers?

  Well, what are the things that a polygraph machine is measuring? When we see the little needle on the paper, what's sending the needle, you know, up and down or not moving much or what's it measuring?

• 39:17Speaker 02

  Perhaps the easiest way to visualize this is by talking through the equipment that you have on, attached to you when you have a polygraph test done. So the first thing that you will notice is there's a blood pressure cuff wrapped around your arm. So that's measuring your pulse and also your blood pressure. So how fast your heart is beating and what your blood pressure is doing at the same time. Then the second thing you'll have is you'll have two bands wrapped around your chest, one to measure your breathing around the kind of higher, higher up your chest and then one around your diaphragm for lower down. And those are measuring your breathing rate. So how fast you're taking an air and it's thought that. Liars might hold their breath while they're formulating a response to a question that they know they're going to have to lie on or things like that. And then the final thing is called galvanic skin response, which is basically sweat.

• 40:02Speaker 02

  So this is usually attached to the fingertip and this measures how much you're sweating. So each of those measurements will have a corresponding line on the polygraph chart and then the examiners will learn to interpret those lines in tandem to look for kind of signs of what they consider to be lying.

• 40:21Mike Carruthers?

  And do each one of those things have its own little needle?

• 40:26Speaker 02

  Yeah, that's right. Yeah. So and actually, the technology hasn't changed since, you know, the nineteen twenties, really. So in the initial one, yeah, you'd have four different lines on the chart and then it's the kind of combination of those lines that will appear on the chart, you know, in com paper or nowadays it's on a computer screen.

• 40:47Mike Carruthers?

  So my sense is if somebody were to hook me up to one of those machines and, you know, strap things around my chest and a blood pressure cuff, that I would, that my blood pressure would go up just because of the experience of having to do this test and people suspecting I'm lying, that that just being there would make me look like a liar?

• 41:12Speaker 02

  Exactly. The machine is supposed to work on the premise that liars will be nervous, but people are nervous for all sorts of reasons, right? There's no way of telling whether someone is sweaty because they're lying or sweaty because they're nervous about being wrongly accused of lying.

• 41:26Mike Carruthers?

  Or maybe they're lying.

• 41:29Speaker 02

  Or maybe they're lying, yeah, but you can't, you just can't tell. And that's the big problem with the polygraph, you know, even if ninety percent of people would show a particular result on the polygraph, that doesn't mean it's true for everyone. And that's the big problem. There's no single telltale sign of lying that works for everyone all of the time. Researchers in the field say there's no Pinocchio's nose, you know, there's nothing that is going to give you the right answer with enough certainty, enough times to be valid to use in a courtroom setting, for instance.

• 41:58Mike Carruthers?

  At what point did people, I mean, was it assumed more or less from the beginning that this was pretty accurate and then somebody showed that it wasn't? Or were people skeptical from the beginning? Or how did it kind of fall out of favor to the extent that courts won't use it?

• 42:18Speaker 02

  So it's actually been barred from the courtroom for a really, really long time. So Larson invented the machine in nineteen twenty one. And then there was a famous case called the Frye case, which was set a precedent that the polygraph couldn't be used in the courtroom. And that was actually in, I think, nineteen twenty three. So it really wasn't long afterwards. But even the people that invented the polygraph kind of had their misgivings about it quite early on and thought that it shouldn't have been used as widely as it was being used even back then. So John Larson, who invented it, was really excited about it for the first couple of years, but then he saw how his scientific caution kind of got blown away by hype and press coverage.

• 43:01Speaker 02

  And then by the end of his life, he hated the machine. He thought it was like a Frankenstein's monster that he'd unleashed on the world. So I would say that within ten years, there were serious doubts about the efficacy of the polygraph. But by then, the hype and the, you know, the drama around it sort of overtook it all and it really snowballed.

• 43:23Mike Carruthers?

  The guy or the woman who's operating the machine and then asking the questions, it would seem that the results might be open to interpretation, that one, one person might administer a test and say one thing and another person might interpret it another way. Or is it an objective result?

• 43:44Speaker 02

  It's very, very subjective. So yes, you can give two different examiners the same chart to examine and they could come up with completely different answers as to whether the person was lying.

• 43:53Mike Carruthers?

  It almost sounds like because it is so subjective and because people are so different, that it's, it's basically worthless.

• 44:05Speaker 02

  Yes, essentially, that would be my contention. I mean, I think that the machine has obviously helped to put criminals away. There's no getting around that. But the problem is that it's also perpetrated serious miscarriages of justice. Essentially, the reason the polygraph has been so successful is because of the theatre around it. Right? It works because people believe it works so that the mere threat of being attached to a polygraph can compel someone to confess to the crime before the exam even takes place. Because they're so worried about being found out because they believe the machine works even if it doesn't actually work.

• 44:37Mike Carruthers?

  Yeah, that sounds like that's the real secret to the polygraph that that if somebody refuses to take one, maybe we better give this guy a closer look.

• 44:47Speaker 02

  That, I mean, you don't even need a polygraph machine some of the time. So there's a great story from David Simon's book about policing in Baltimore where he describes this situation. And I think it's recreated in an episode of The Wire, actually, where the police officers didn't have a polygraph available, so they used a Xerox machine. And they put the subject's hand on a Xerox machine and told the subject that it was a lie detector and then just got the machine to print out a piece of paper with "he's lying" written on it. And that was enough to kind of kind of trick the suspect into actually, you know, believing that the machine could read their mind.

• 45:19Mike Carruthers?

  Well, it does the job. It get the guy to confess because he thinks he's in a corner, basically.

• 45:25Speaker 02

  Exactly. Yes, it does the job. It's all about the theatre of it. And actually, they realized this very early on, the inventors of the polygraph, that it was largely about the theatre. So they did take steps to amp that up.

• 45:38Mike Carruthers?

  So the people who administer the test and interpret the results, what's their training? What, I mean, if if two people can look at the same chart and come up with different results, what, how how did they get to come up with those different results? Because they were trained how?

• 45:55Speaker 02

  Yes. So to train to become a polygraph examiner, well, there's no real regulation stopping you from just buying a polygraph machine on eBay and then advertising your services. But most polygraph examiners that are operating today have certification from something called the American Polygraph Association. However,

• 46:17Speaker 02

  In order to get certification from the American Polygraph Association requires a 12-week course, I think it is. So we're talking about a few thousand dollars, a few months, and then that's it.

• 46:30Mike Carruthers?

  There are other ways that people claim to be able to tell if someone is lying. And it's usually, you know, it's usually not just one thing, but if you watch somebody over a period of time and compare it to a baseline, that you can get a sense whether they're lying. And I'm wondering, has anyone ever tested the polygraph versus those kind of ways of determining deception? And to see which is more accurate?

• 46:59Speaker 02

  Those ways of, I don't know if there's ever been a kind of a direct comparison done with the same subjects, but a lot of other methods of detecting lies have been very thoroughly tested. But they also have from the same sort of fatal flaw, which is you can't be sure. And with something like lie detection, you kind of need to be sure, right? If you are running someone in a murder case where the crime is, you know, capital punishment, then you need to be 100% sure that they are going to be susceptible to the particular type of lie detector you're trying to use on them. And there's no evidence to suggest that everyone will display exactly the same range of physiological responses to telling a lie.

• 47:40Speaker 02

  And actually, you might expect that a psychopath or a serial killer might not actually show the range of emotional responses that you would expect. So maybe those people are actually less susceptible to lie detectors than your ordinary man on the street, because they already have a kind of different range of emotional responses. And actually, that's what we're looking for with the polygraph.

• 47:59Mike Carruthers?

  So it's still used today, and is it basically used because it's better than nothing?

• 48:06Speaker 02

  Yeah, I think it's used because it's convenient. So if you can get a confession from someone using the polygraph, that's much cheaper than.

• 48:16Speaker 02

  Having to go out and collect all the evidence and then take the case to court and all that kind of stuff. It is solely being superseded by different forms of lie detection in some fields. I think there's kind of new inventions that are cheaper to run than the polygraph that don't require a trained examiner and all this kind of stuff. So we might see it shifting away from the polygraph towards new forms of lie detection in the future. But it's convenient, people believe it works and, you know, it gets results sometimes. Actually, a lot of the time it gets the results that the people running the test are looking for. Whether it actually gets to the truth is a kind of different question.

• 48:51Mike Carruthers?

  When a polygraph test is given, it's all yes or no questions, right? It isn't so tell me about, it's strictly yes or no.

• 49:02Speaker 02

  That's right. The way it's portrayed in film and TV is quite wrong, actually, because it's kind of portrayed as this back and forth between the investigator and the suspect. But yes, actually, the way that the test was originally designed was, yeah, these very, very slow yes or no questions repeated multiple times over the course of several hours. The suspect gives yes, yes or no responses because the point is you want to minimize the difference between the control questions, which are irrelevant to the crime, and the target questions, which are about the crime. So you want the suspect to be sitting as still as possible to reduce interference. So you don't want them to be spinning out long sentences and things like that. You want to keep the differences to a minimum so that when they do lie, it shows up on the chart, or at least that's the theory, anyway.

• 49:48Mike Carruthers?

  Well, it's pretty interesting. The polygraph has really had pretty good PR, it seems, for a long time, given the facts. I mean, it still gets used, people still believe it works, and yet there isn't a whole lot of science behind it, it seems.

• 50:07Speaker 02

  Yeah, that's right. It's just somehow become sort of embedded in the justice system. And I think a lot of people have debunked it. It's been debunked by numerous academic studies, government reports, expert analysis on several occasions, but it just sort of refuses to go away. And I think that's probably something to do with human nature, right? We're drawn to this idea that a machine can reveal the truth, right? Especially in a time when truth is so difficult to find. I think this idea that there is a machine that can do it for us is still quite compelling.

• 50:40Mike Carruthers?

  Well, now I think I want to, I want to get hooked up. I want to, I want to have a polygraph test just to have the experience. I've been talking with Amit Katwala. He is an award winning journalist, a senior writer at Wired, and author of the book Tremors in the Blood: Murder, Obsession, and the Birth of the Lie Detector. And you will find a link to that book in the show notes. Thank you, Amit.

• 51:05Speaker 02

  Thanks so much for having me. I appreciate it.

• 51:10Mike Carruthers?

  Women drivers have gotten a bad rap over the years. Statistics show that actually they're better drivers overall than men are. Women are involved in fewer accidents, have fewer insurance claims, and don't wind up with as many moving violations as men do. And some surveys have found that women are also superior parkers. Researchers watched 2,500 drivers park and scored them on technique, precision, and time taken. The women were better at picking accessible spaces and at lining up their vehicles to park them. Women outparked the guys in parallel parking situations as well. They were more likely to back in,

• 51:51Mike Carruthers?

  which is the method preferred by driving experts. And that is something you should know. If you enjoyed today's podcast, don't keep it to yourself. Share it with someone you know. I'm Mike Carruthers. Thanks for listening today to Something You Should Know.

• 52:07Speaker 03

  Members who switched to USAA Auto Insurance saved an average of $80 a month. All you have to do is switch once and then enjoy the same excellent service year after year. Visit usaa.com/aut quote to see how much you could save.