Hello there, it's me Josh and for this week's s Y s K Selects, I've chosen our classic episode on Lie Detectors. It's a pretty nifty little episode about a pretty dodgy piece of forensic science with a wow of a backstory. It is classic stuff you should know, so I hope you enjoy. Welcome to Stuff you Should Know, a production of My Heart Radios How Stuff Works. Hey, and welcome to the podcast. I'm Josh Clark. With me is always as Charles to be Chuck Bryant liar you you could tell there's the ways you can find out Chuck Um. We'll get to that in a minute. This is stuff you should know. Let me finish, Okay, and it's you lie. Remember that guy, Yeah, Joe joey Pants or whatever the congressman's name. Yeah, Saturday Night Live a funny skit that he had gotten a whole group of people to all stayed up at once, wasn't the deal? Tell it? And well, yeah, and he supposed he had a whole group of senators that we're gonna all stand up and yell you lie. And then he was the only one that did it. That's because he was out of the room when they were like, no, we can't do that, that's funny. Yeah. So um, oh, we're talking about a lot of detectors. But let me take you back, all right to a little place in time and space called the jazz age early nineteen twenties. Yeah. No, that's the beat Knicks that did that. Okay, Um, I'm sure a jazz person snapped their fingers at one point. Sure, um, but not like that, all right. It was more like like Coltrane style, just like that. Anyway. This is Chuck in Berkeley, California, at u c l A, Berkeley, And there is a place there called, um, the College Hall, which was a women's dorm. And in that year there were a theft, a string of there was a string of um thefts, cash rings, um, pretty much anything of value went missing for a little while there. And uh, there's a man working at the Berkeley Police Department in the girl's dorm. Yeah, okay, called College Hall. There was a man working in the in the Berkeley Police Department's name is John Larson. And John Larson was the first cop ever to have a pH d. And he had gotten interested in this device called a cardio neumo psychograph which had been invented just a few years before by another guy named William Marston. And William Marston was a lawyer in a Harvard shrink and he also as an aside creative wonder Woman with her Lasso of truth. Really, he's the guy who invented the what's now called the polygraph. What about the wonder Woman? He created Wonder Woman, the character. He was kind of a renaissance man. But that's William Marston. John Larson works at the at the Berkeley Police Department and he's become interested in this thing, the cardio neumo psychograph, and he realizes, okay, this is a perfect chance to apply it. So he rounds up, you know, some suspects. He does some some normal police work and finds out who the suspects are in this in this hall, and he rounds him up, brings him down the station, and he starts hooking people up to this um this machine. And he gets to this one woman, her name is Helen Graham, and guilty, yes, pretty much is what he does. He goes, ms. Graham, this machine is saying that you're that you took this, that you you took the money, you know, did you? Um and he said that he noted on the machine a sharp dropping blood pressure followed by a sudden rise. And then after that this woman flew into a rage. She tried to attack the machine. She went crazy. So they they basically stringer along for a few days, and then finally she confesses, and it's the first time that a polygraph was ever used to to um solve a crime. Ever, that that was probably the heyday because before the people knew what it was, they could just say this machine says that you're guilty, and they would be like, oh my god, that's exactly right. Very early on, some of the early proponents, specifically a guy named a Leonard Keeler, um recognized the placebo effect value before anyone knew there was a placebo effect, but the placebo effect value of a polygraph. That just the idea, if you believed in this machine and that it could rude outlies, then it could force you to confess just being hooked up to it. You weren't going to pass it. They should have called it the guilt box. They called it the magic lie detector is one of the one of the things that they called it. Yeah, Leonard Keeler called it that he worked with John Larson at the Berkeley Police Department, and eventually, over time John Larson saw the what he considered the true youth behind the light detector and the fact that it kept being cold light detector, which is driving him crazy. Um, and he eventually distanced himself from it later on in his career. Um, but Leonard Keeler ran around marketing it to anyone and everyone saying, just having this is going to not only help you hire um, more more truthful, forthright people, but it's going to keep them in line while they're working for you, because they know you've got access to this thing and you can strap them to it at any time. Yeah, so that's where the polygraph came from. Yeah, there's a little prehistory to just to give them their due. Uh. In eight Cesaire Lambroso, he's an Italian criminologist. He measured changes in blood pressure for police cases. In a nineteen o four a device by Vittorio Binosi measured breathing and so they were early nineteen hundreds, late eighteen hundreds. They were kind of on the scene of of measuring these things. And Dr James Mackenzie in nineteen o six first mentioned the word polygraph with his instrument that he didn't use to root out the truth, but for uh he did use it when giving medical examination though. And then right before the polygraph was the unigraph unigraph, which was part of what's still used today in the polygraph. Um, it measured respiration. Pretty cool, yeah, um, but then you add to it a couple of other things and you got the polygraph. We could stop here. This is interesting enough right now. So there's no uh you really, there's no um, no one walking the planet who has anything to do with polygraphs that call them lie detectors, And anyone, even the most ardent defender of polygraph technology would correct you if you called it a lie detector. They would be like, it's it's not a lie detector because you can't detect a lie. It's possible. The whole basis of a polygraph is that it is a set of um medical instruments that used to measure changes in things like your heart rate, your respiration, UM and sweatiness. Basically, I would fail. Um, well, a lot of people do fail, and we'll get to that. But um, oh, because you're sweat that's okay. They would they would even hook me up. Um. So when you're hooked up to this machine, the whole point is that it measures these physiological changes in the idea that there you're going to undergo physiological changes based on the concept that a person hooked to this machine who is guilty will experience fear that they're going to be detected. So this machine is designed to detect that fear. That's right, which is really round about. But for a century almost these things were used, um and abused, and it took a while for people that to catch on that. There's a lot to criticize here with polygraphs, Yeah, for sure. All right, so let's get into this um. First of all, we need to point out that analog polygraphs are what you have long seen in movies and TV when they have the little jittery looks like a seismograph on the on the paper scrolling by, and uh, you're hooked up to all these different things on your chest, in your forehead and your fingertips. These days they do that digitally, but it's basically still the same technique. They just don't use the little scrolling needle. Do They have a name for that. It's called an inkfield pen. It is. Yeah. But the three things that they do, Josh, They measure your respiratory rate, as you said, They take newmgraphs, which are rubber tubes filled with air time around your chest and your abdomen, and that is going to measure whether or not you're you know, you start breathing heavy essentially when you get nervous. It monitors your breathing pattern and any changes to it, and it does it pretty cleverly. Right. Yeah. With bellows, it they're filled with air. So when you when you breathe in real deeply or have a change, it's going to displace that into the bellows and that will Originally that was attached, the bellows were literally attached to the mechanical arm that showed the change. These days, as a it's a transducer that converts it digitally electronically, right, it converts it to an electrical pattern, right, Yeah, that probably just says for the same thing. Yeah, um no, I think it looks a lot like it if you look. There's a picture of a modern one and it looks just like But yeah, it's not. It's not a paper read out any longer, which is kind of interesting. Like this technology hasn't hasn't changed on a very fundamental basis for like a hundred years almost. Yeah, I mean the early one from Mackenzie in nineteen o six. They say that a lot of the same components are still very similar today. Right. Um. You also are going to have so you're gonna have two tubes, one around your chest, one around your abdomen. It's um keeping an eye on your breathing. Um. You're going to have a blood pressure cuff which um, which keeps an eye on your heart rate and your blood pressure, and it does it through sound, right. Yeah, I didn't realize this. So when you're when the blood comes in and out of your veins, it creates sound, and sound can also be used to displace air, causing a bellows to contract, which again moved the arm on the scroll and now is created or turned into an electrical pattern. Um, but it's the same thing, but it's sound, which I just think is very neat. Well, and what's also neat is the sweat one. I figured they would have some sort of like a moisturerometer just to detect moisture, but it's called galvanic skin resistance or GSR or electrodermal activity, that's right. And they hook up these fingerplates to galvanometers and they are basically measuring the skin's ability to conduct electricity. And if your skin is moist, it's going to be able to conduct electricity easier. And that's what they're measuring there. It's like the ones the little um heart rate monitors that they clip to your fingertips in the hospital, but these things measure electricity instead, uh, which if you are dry, you're going to conduct less electricity, if you're wet, you're going to conduct more. So since you have so many pores on the end of your fingers and you sweat when you're nervous. There you got done. So you put all this together and um, it paints this picture. It's the A. C. L U among other people, have decried as just what are you doing here? Basically is what the A C l U says, right, Um, what what you have is a picture of a person who is undergoing stress, maybe feeling embarrassment, is maybe just scared to be there, uh, maybe doesn't like having things wrapped around his or her chest. Um, maybe doesn't really like the person asking the questions. The results of these these UM changes in pattern. The data is totally subjective, that's right, which makes polygraphs totally subjective, which takes it in large part out of the realm of science. Yeah, voodoo science is what they call it. And uh, all the proponents will say that a well trained forensic psychophysiologists which is the examiner, can get through all that to still get a good result. They're like, yeah, they know all this stuff, and if you're good, then you can factor that in and still get a good result. So let's talk about what the forensic psychophysiologist does. There's apparently I've seen anywhere between five thousand and ten thousand of them in the US at any given time, UM, and some of them belong to professional organizations. I think probably maybe half or third, depending on where you are on the on the estimate, UM belonged to any number of professional organizations. Some have no accreditation whatsoever, um, but are still able to open up shops depending on the state there in. Some states have zero laws about being a forensic psychophysiologist a k A polygraph examiner. That's right, but there is also some there are programs out there. Uh. The who wrote this article, Kevin bondser I don't know. I think so he he UM interviewed a guy who founded the Accidon Academy exit Haunt as a manufacturer of polygraphs, and they founded this academy as well, where um, you go through a certain amount of training to become a forensic psychophysiologist. And he actually interviewed that guy. Yeah, his name's Bobb Lee Lee. Uh, and Lee says that if you come to their academy, UM, you have to have a baccalaurea degree bachelor's right, or you have to have at least five years investigative experience and an associate's degree. Um, you have to take a ten week course, and after you complete the ten week course, you have to carry out twenty five polygraph examinations and submit them to be reviewed. Uh. So these are like real life ones. I guess you're working with your local police department or whatever. Maybe you're already a cop UM and you have to submit it to the Accident Academy board for a review. And then once they're all reviewed and everybody's all thumbs up, you are a life since I guess. But you're not licensed because there's no licensing body. Um, you are you graduate? I guess is is what they call it. So that's as accredited as it gets. I guess. And like you said, Um, proponents of polygraph testing say that there, if you're a good FP, you're gonna be able to structure everything correctly so that you can see past somebody who's just who sweats a lot like you, or who gets stressed out easily like me, Um, and design your questions appropriately, and you're gonna be able to to to figure out whether this person is deceptive or not. So how how would you do that? Chuck? Well, we should talk about the test itself. I guess. Uh, you're gonna you're gonna go in and you're gonna get a pretest before you get strapped up to anything. Could take about an hour. This is just you and those the only two people in the room. You're not surrounded by folks like in the movies and stuff, although a movie sometimes it's just two people, I guess. But the pretest that you're just going to get an interview basically about basically about why you're being investigated. Uh, they're also gonna be profiling you and checking you out and just seeing what kind of questions you respond to and what might make you nervous, just so they'll be better informed about how to properly question you once you're all strapped in right and the pretest where you're just kind of hanging out with them casually, the examiners also kind of getting info out of you that you might not be aware of, like, um, if you are uh, if you talk leisurely about your favorite beer at one point and how you like it a lot, and then later on it also comes up that you have to drive a lot um, they might come up with it. They might use that for a control question, UM, which could be something like have you ever driven under the influence of alcohol? And a control question is something where you would have to admit guilt um, and you may not want to, but it's such a broad question that just about anybody is guilty of it, like have you ever lied to somebody? Have you ever um stolen anything? That kind of thing, So where if you say no, they now have a baseline for what it looks like when you lie. That they can make a reasonable assumption that you have just lied. And any of the data UM captured on the polygraph they're going to use to analyze everything else off of. And that's pretty much it. That's the test, and afterward you have the post tests where they look at all the data and chart out whether or not they think you're deceptive and aware. Like on this question you were deceptive. On this question you may have been deceptive. It's kind of hard to tell. On this one you definitely were deceptive. So so, and it's all in it's all in relation to that control question, that baseline, right, So if you if your deception, if you if on questions where I mean, they're going to have to talk to the police as well too and say what do you want to know out of this person? So they'll design questions around that as well. Um, so they may have a question like, um, are you wearing a blue shirt? That may be question one, it's irrelevant, right. Question two is, um, have you ever lied to your boss? That's the control question, and then question three is something like you know, did you steal the cookie from the cookie jar? Like that's the one that the cops want them to ask. They'll compare the results of Q three against Q two and if they're the same or you can't really tell, that's in UH in that that's an UH inconclusive tests. So that's it. I mean, like you said, that's that's polygraph. It's pretty easy, it is. It's Uh, it's um jar ringly easy, considering that it's used in legal cases a lot, right, Yes, that's true. Um. People try to to battle the LDE detector in various ways or a little tricks that the Internet says works, like taking a sedative or putting any perspirint on your fingers, which seems like they would make you wash your hands, Uh, putting attack in your shoe, and anytime you get asked a question, every single time you stomp on the tack. And the idea is that you're just gonna skew the tests so they all look the same, so your body has the same reaction no matter what's going on, like they I guess, if you press on the tack, your physiological response could overwhelm any response to the question. Right. Um, Like I said, there, these these things are used in legal cases, but with caveats. Right. If you undergo a polygraph, Uh, whether you fail or pass, it doesn't really matter legally speaking, right, um, because of unless you're in New Mexico. Yeah, this is the only state that allows it just openly. Like if you take a polygraph like, it's admissible in court yeah, every other state. Um. Usually the both sides have to agree on it being admitted or um. The judge has to say, yeah, we're gonna admit this one, right, Yeah. And federally, the judge decides whether or not they're going to admit it, right, And I guess state judges kind of follow that federal ruling of polygraphing. Yeah, And it's sort of a crapshoot if a federal judge is gonna allow it or not. There's no precedent really to where they say we have to or we don't have to. Right. So, what are the problems with this um? The problems with a polygraph um or that it's subjective, Right, that's a big one. But also because there because it's subjective, you can get what are called false positives and false negatives. Yeah, and you don't want that because then the test itself is just not valid. Right. Uh. But I mean that a lot of people use that as evidence that polygraph polygraphy shouldn't be done at all, that it's not valid. False positive and polygraph thing is when you find somebody who is deemed deceptive but was telling the truth. False negative is when somebody who wasn't telling the truth UM is deemed truthful. Like Gary Ridgeway, the Green River killer. They had him for a little while and gave him a polygraph and he passed and they let him go and he went and killed a bunch more women. All right, that's right. I didn't know that. Actually, Yeah, there's also the uh. You know, the federal government is the largest uh consumer of these exams, and if you work for the federal government, you've probably had one to get the job. But you can't do that in the private sector thanks to the Polygraph Protection Act Employee Polygraph Protection Act in the late eighties, they said, you can't force your employees to do this US. You can request it, but if they don't want to do it, you can't fire them because of it. You just can't do it, right, not in private land, right unless you have a contract with the government, and then that's not valid. But yeah, the the federal government is the largest opponent to him in court, but also the largest consumer. And imagine that, UM. And there's been a lot of cases that shaped its admissibility or not. But the polygraph it seems like it's kind of honest way out. I wrote an article about UM M R I being used as lie detectors, and that's starting to kind of come into fashion the more we start to understand, like how lies are born in the brain, being able to see it and saying this is the pattern that will happen. UM. If this person is lying and then that pattern happens, they say, what, we know you're lying. We just saw that live form in your brain. That makes sense, yes, But at the same time, people who understand MR eyes say, is way too early to be doing that. And even if we can do it with accuracy, there are a lot of moral and ethical questions to it as well that we need to address. First always uh and then penile plus demography. What's that? So? Remember the the UM newmeographs that go around the chest and the abdomen. Imagine one of those that goes around the penis and it does the same thing. It the text changes in contraction and girth. It's a perfect way to put it UM and it's used to detect arousal. They use it for UM sex offenders. It's under at least as much attack as regular UM polygraphs. But I wrote this blog post called UM using science to root out late in homosexuality among homophobes. A study at U g A used UH penile pleas plesismography UM to find if anyone who they had deemed homophobic be came aroused to inexposed to homosexual pornography. Yeah, it's it's one of the better posts I've ever written. Cheese, all right, that's our future. I guess peno pleathismography for everyone, everyone with a penis at least and then chuck. Lastly, I want to encourage everybody, if this has piqued your interest about lie detectors, to go watch the shoe Court shoe store job interview clip from Mr Show on YouTube. You remember that one. It's very good weather friend Paula Thompkins and he has a breakthrough. Was seeing that one? Yeah, yeah, good old p f T yep. And that's it for lie detectors, right, Yeah. I want to take a test. If there's someone in the Atlanta area that administers these and would be willing to give me a lie detector test, I would love to do that, Okay, and I'll watch yes UM as long as I can, you know, approve the questions or not approve them. But I don't want to be like rooted out as some miscreant. That's a little late for that. Just keep it above board. UM. If you want to know more about lie detectors and play with some Lie detector flash animation, you can do that by typing in lie detector on this in the search bar on how stuff works dot com and UM, that means it's time for listener mail. That's right, Josh. This is from Brad and Brad. If you remember, we had a list of suggestions from a listener not too long ago that thought our podcast could be a lot better if we changed a few things. Brad has some suggestions of his own of how we can make the podcast better. We should both have nicknames zazz up the actual name like welcome to stuff you should Know with j C and the Dingo, sit back while getting a big helping of knowledge from Chucko and the Duck. I second the suggestion to remove the personal anecdotes should be moved to a separate podcast called the Josh and Chuck Memoirs. Daily one hour podcasts can recount your lives from birth to present, focusing on depressing stories that are marginally factual. It's in development, Chuck, please your raise your voice one octave, Josh lower yours one octave. What okay? So now this is how I talk to the opening of the podcast should be a description of what each of you ate that day and the number of trips to the bathroom. This allows the listener to keep track at home. Hedgehogs, brain surgeons, arcades, and Bolivian politics are underrated, under sorry, underrepresented on your podcast at least should be about these subjects. Do not exclude listener mail. Instead, create a quieter audio track reading the listener mail and overlay it on the rest of the podcast. That way, listeners can hear both the mail and the main content at the same time. This is a pretty good idea. Why not set the pod we literally driving people in Spain? If we did that, why not set the podcast to a backdrop of tribal drums and jungle animal noises would give it an exotic feel. That's over the listener mail track, over the whole thing, So that'd be three tracks deep. Yes, and it would lead to suspense for the listener to wonder if you will be eaten by jaguars? Uh. And it was clear from the podcast on Mummies neither of you had ever been mummified. Please refrain from explaining topics that you don't have personal experience with. And then the final suggestion, just retail episodes of this American Life that went that last one went down like the Dave Glitterman top. Finally, so that's Brad, Thanks brand. Those are all great ideas. Three tracks all in one, streaming at once together listener mail quietly to podcast and tribal drumming and jungle noises. Yes, um, let's see. If you have access to a polygraph and want to hook chuck up to it, let us know. You can let us know on Facebook at facebook dot com, slash stuff you Should Know, You can tweet to set s y s k podcast, and you can send us a regular old email at stuff podcast at how stuff works dot com. Stuff you Should Know is a production of iHeart Radio's How Stuff Works. 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Hello there, it's me Josh and for this week's s Y s K Selects, I've chosen our classic episode on Lie Detectors. It's a pretty nifty little episode about a pretty dodgy piece of forensic science with a wow of a backstory. It is classic stuff you should know, so I hope you enjoy. Welcome to Stuff you Should Know, a production of My Heart Radios How Stuff Works. Hey, and welcome to the podcast. I'm Josh Clark. With me is always as Charles to be Chuck Bryant liar you you could tell there's the ways you can find out Chuck Um. We'll get to that in a minute. This is stuff you should know. Let me finish, Okay, and it's you lie. Remember that guy, Yeah, Joe joey Pants or whatever the congressman's name. Yeah, Saturday Night Live a funny skit that he had gotten a whole group of people to all stayed up at once, wasn't the deal? Tell it? And well, yeah, and he supposed he had a whole group of senators that we're gonna all stand up and yell you lie. And then he was the only one that did it. That's because he was out of the room when they were like, no, we can't do that, that's funny. Yeah. So um, oh, we're talking about a lot of detectors. But let me take you back, all right to a little place in time and space called the jazz age early nineteen twenties. Yeah. No, that's the beat Knicks that did that. Okay, Um, I'm sure a jazz person snapped their fingers at one point. Sure, um, but not like that, all right. It was more like like Coltrane style, just like that. Anyway. This is Chuck in Berkeley, California, at u c l A, Berkeley, And there is a place there called, um, the College Hall, which was a women's dorm. And in that year there were a theft, a string of there was a string of um thefts, cash rings, um, pretty much anything of value went missing for a little while there. And uh, there's a man working at the Berkeley Police Department in the girl's dorm. Yeah, okay, called College Hall. There was a man working in the in the Berkeley Police Department's name is John Larson. And John Larson was the first cop ever to have a pH d. And he had gotten interested in this device called a cardio neumo psychograph which had been invented just a few years before by another guy named William Marston. And William Marston was a lawyer in a Harvard shrink and he also as an aside creative wonder Woman with her Lasso of truth. Really, he's the guy who invented the what's now called the polygraph. What about the wonder Woman? He created Wonder Woman, the character. He was kind of a renaissance man. But that's William Marston. John Larson works at the at the Berkeley Police Department and he's become interested in this thing, the cardio neumo psychograph, and he realizes, okay, this is a perfect chance to apply it. So he rounds up, you know, some suspects. He does some some normal police work and finds out who the suspects are in this in this hall, and he rounds him up, brings him down the station, and he starts hooking people up to this um this machine. And he gets to this one woman, her name is Helen Graham, and guilty, yes, pretty much is what he does. He goes, ms. Graham, this machine is saying that you're that you took this, that you you took the money, you know, did you? Um and he said that he noted on the machine a sharp dropping blood pressure followed by a sudden rise. And then after that this woman flew into a rage. She tried to attack the machine. She went crazy. So they they basically stringer along for a few days, and then finally she confesses, and it's the first time that a polygraph was ever used to to um solve a crime. Ever, that that was probably the heyday because before the people knew what it was, they could just say this machine says that you're guilty, and they would be like, oh my god, that's exactly right. Very early on, some of the early proponents, specifically a guy named a Leonard Keeler, um recognized the placebo effect value before anyone knew there was a placebo effect, but the placebo effect value of a polygraph. That just the idea, if you believed in this machine and that it could rude outlies, then it could force you to confess just being hooked up to it. You weren't going to pass it. They should have called it the guilt box. They called it the magic lie detector is one of the one of the things that they called it. Yeah, Leonard Keeler called it that he worked with John Larson at the Berkeley Police Department, and eventually, over time John Larson saw the what he considered the true youth behind the light detector and the fact that it kept being cold light detector, which is driving him crazy. Um, and he eventually distanced himself from it later on in his career. Um, but Leonard Keeler ran around marketing it to anyone and everyone saying, just having this is going to not only help you hire um, more more truthful, forthright people, but it's going to keep them in line while they're working for you, because they know you've got access to this thing and you can strap them to it at any time. Yeah, so that's where the polygraph came from. Yeah, there's a little prehistory to just to give them their due. Uh. In eight Cesaire Lambroso, he's an Italian criminologist. He measured changes in blood pressure for police cases. In a nineteen o four a device by Vittorio Binosi measured breathing and so they were early nineteen hundreds, late eighteen hundreds. They were kind of on the scene of of measuring these things. And Dr James Mackenzie in nineteen o six first mentioned the word polygraph with his instrument that he didn't use to root out the truth, but for uh he did use it when giving medical examination though. And then right before the polygraph was the unigraph unigraph, which was part of what's still used today in the polygraph. Um, it measured respiration. Pretty cool, yeah, um, but then you add to it a couple of other things and you got the polygraph. We could stop here. This is interesting enough right now. So there's no uh you really, there's no um, no one walking the planet who has anything to do with polygraphs that call them lie detectors, And anyone, even the most ardent defender of polygraph technology would correct you if you called it a lie detector. They would be like, it's it's not a lie detector because you can't detect a lie. It's possible. The whole basis of a polygraph is that it is a set of um medical instruments that used to measure changes in things like your heart rate, your respiration, UM and sweatiness. Basically, I would fail. Um, well, a lot of people do fail, and we'll get to that. But um, oh, because you're sweat that's okay. They would they would even hook me up. Um. So when you're hooked up to this machine, the whole point is that it measures these physiological changes in the idea that there you're going to undergo physiological changes based on the concept that a person hooked to this machine who is guilty will experience fear that they're going to be detected. So this machine is designed to detect that fear. That's right, which is really round about. But for a century almost these things were used, um and abused, and it took a while for people that to catch on that. There's a lot to criticize here with polygraphs, Yeah, for sure. All right, so let's get into this um. First of all, we need to point out that analog polygraphs are what you have long seen in movies and TV when they have the little jittery looks like a seismograph on the on the paper scrolling by, and uh, you're hooked up to all these different things on your chest, in your forehead and your fingertips. These days they do that digitally, but it's basically still the same technique. They just don't use the little scrolling needle. Do They have a name for that. It's called an inkfield pen. It is. Yeah. But the three things that they do, Josh, They measure your respiratory rate, as you said, They take newmgraphs, which are rubber tubes filled with air time around your chest and your abdomen, and that is going to measure whether or not you're you know, you start breathing heavy essentially when you get nervous. It monitors your breathing pattern and any changes to it, and it does it pretty cleverly. Right. Yeah. With bellows, it they're filled with air. So when you when you breathe in real deeply or have a change, it's going to displace that into the bellows and that will Originally that was attached, the bellows were literally attached to the mechanical arm that showed the change. These days, as a it's a transducer that converts it digitally electronically, right, it converts it to an electrical pattern, right, Yeah, that probably just says for the same thing. Yeah, um no, I think it looks a lot like it if you look. There's a picture of a modern one and it looks just like But yeah, it's not. It's not a paper read out any longer, which is kind of interesting. Like this technology hasn't hasn't changed on a very fundamental basis for like a hundred years almost. Yeah, I mean the early one from Mackenzie in nineteen o six. They say that a lot of the same components are still very similar today. Right. Um. You also are going to have so you're gonna have two tubes, one around your chest, one around your abdomen. It's um keeping an eye on your breathing. Um. You're going to have a blood pressure cuff which um, which keeps an eye on your heart rate and your blood pressure, and it does it through sound, right. Yeah, I didn't realize this. So when you're when the blood comes in and out of your veins, it creates sound, and sound can also be used to displace air, causing a bellows to contract, which again moved the arm on the scroll and now is created or turned into an electrical pattern. Um, but it's the same thing, but it's sound, which I just think is very neat. Well, and what's also neat is the sweat one. I figured they would have some sort of like a moisturerometer just to detect moisture, but it's called galvanic skin resistance or GSR or electrodermal activity, that's right. And they hook up these fingerplates to galvanometers and they are basically measuring the skin's ability to conduct electricity. And if your skin is moist, it's going to be able to conduct electricity easier. And that's what they're measuring there. It's like the ones the little um heart rate monitors that they clip to your fingertips in the hospital, but these things measure electricity instead, uh, which if you are dry, you're going to conduct less electricity, if you're wet, you're going to conduct more. So since you have so many pores on the end of your fingers and you sweat when you're nervous. There you got done. So you put all this together and um, it paints this picture. It's the A. C. L U among other people, have decried as just what are you doing here? Basically is what the A C l U says, right, Um, what what you have is a picture of a person who is undergoing stress, maybe feeling embarrassment, is maybe just scared to be there, uh, maybe doesn't like having things wrapped around his or her chest. Um, maybe doesn't really like the person asking the questions. The results of these these UM changes in pattern. The data is totally subjective, that's right, which makes polygraphs totally subjective, which takes it in large part out of the realm of science. Yeah, voodoo science is what they call it. And uh, all the proponents will say that a well trained forensic psychophysiologists which is the examiner, can get through all that to still get a good result. They're like, yeah, they know all this stuff, and if you're good, then you can factor that in and still get a good result. So let's talk about what the forensic psychophysiologist does. There's apparently I've seen anywhere between five thousand and ten thousand of them in the US at any given time, UM, and some of them belong to professional organizations. I think probably maybe half or third, depending on where you are on the on the estimate, UM belonged to any number of professional organizations. Some have no accreditation whatsoever, um, but are still able to open up shops depending on the state there in. Some states have zero laws about being a forensic psychophysiologist a k A polygraph examiner. That's right, but there is also some there are programs out there. Uh. The who wrote this article, Kevin bondser I don't know. I think so he he UM interviewed a guy who founded the Accidon Academy exit Haunt as a manufacturer of polygraphs, and they founded this academy as well, where um, you go through a certain amount of training to become a forensic psychophysiologist. And he actually interviewed that guy. Yeah, his name's Bobb Lee Lee. Uh, and Lee says that if you come to their academy, UM, you have to have a baccalaurea degree bachelor's right, or you have to have at least five years investigative experience and an associate's degree. Um, you have to take a ten week course, and after you complete the ten week course, you have to carry out twenty five polygraph examinations and submit them to be reviewed. Uh. So these are like real life ones. I guess you're working with your local police department or whatever. Maybe you're already a cop UM and you have to submit it to the Accident Academy board for a review. And then once they're all reviewed and everybody's all thumbs up, you are a life since I guess. But you're not licensed because there's no licensing body. Um, you are you graduate? I guess is is what they call it. So that's as accredited as it gets. I guess. And like you said, Um, proponents of polygraph testing say that there, if you're a good FP, you're gonna be able to structure everything correctly so that you can see past somebody who's just who sweats a lot like you, or who gets stressed out easily like me, Um, and design your questions appropriately, and you're gonna be able to to to figure out whether this person is deceptive or not. So how how would you do that? Chuck? Well, we should talk about the test itself. I guess. Uh, you're gonna you're gonna go in and you're gonna get a pretest before you get strapped up to anything. Could take about an hour. This is just you and those the only two people in the room. You're not surrounded by folks like in the movies and stuff, although a movie sometimes it's just two people, I guess. But the pretest that you're just going to get an interview basically about basically about why you're being investigated. Uh, they're also gonna be profiling you and checking you out and just seeing what kind of questions you respond to and what might make you nervous, just so they'll be better informed about how to properly question you once you're all strapped in right and the pretest where you're just kind of hanging out with them casually, the examiners also kind of getting info out of you that you might not be aware of, like, um, if you are uh, if you talk leisurely about your favorite beer at one point and how you like it a lot, and then later on it also comes up that you have to drive a lot um, they might come up with it. They might use that for a control question, UM, which could be something like have you ever driven under the influence of alcohol? And a control question is something where you would have to admit guilt um, and you may not want to, but it's such a broad question that just about anybody is guilty of it, like have you ever lied to somebody? Have you ever um stolen anything? That kind of thing, So where if you say no, they now have a baseline for what it looks like when you lie. That they can make a reasonable assumption that you have just lied. And any of the data UM captured on the polygraph they're going to use to analyze everything else off of. And that's pretty much it. That's the test, and afterward you have the post tests where they look at all the data and chart out whether or not they think you're deceptive and aware. Like on this question you were deceptive. On this question you may have been deceptive. It's kind of hard to tell. On this one you definitely were deceptive. So so, and it's all in it's all in relation to that control question, that baseline, right, So if you if your deception, if you if on questions where I mean, they're going to have to talk to the police as well too and say what do you want to know out of this person? So they'll design questions around that as well. Um, so they may have a question like, um, are you wearing a blue shirt? That may be question one, it's irrelevant, right. Question two is, um, have you ever lied to your boss? That's the control question, and then question three is something like you know, did you steal the cookie from the cookie jar? Like that's the one that the cops want them to ask. They'll compare the results of Q three against Q two and if they're the same or you can't really tell, that's in UH in that that's an UH inconclusive tests. So that's it. I mean, like you said, that's that's polygraph. It's pretty easy, it is. It's Uh, it's um jar ringly easy, considering that it's used in legal cases a lot, right, Yes, that's true. Um. People try to to battle the LDE detector in various ways or a little tricks that the Internet says works, like taking a sedative or putting any perspirint on your fingers, which seems like they would make you wash your hands, Uh, putting attack in your shoe, and anytime you get asked a question, every single time you stomp on the tack. And the idea is that you're just gonna skew the tests so they all look the same, so your body has the same reaction no matter what's going on, like they I guess, if you press on the tack, your physiological response could overwhelm any response to the question. Right. Um, Like I said, there, these these things are used in legal cases, but with caveats. Right. If you undergo a polygraph, Uh, whether you fail or pass, it doesn't really matter legally speaking, right, um, because of unless you're in New Mexico. Yeah, this is the only state that allows it just openly. Like if you take a polygraph like, it's admissible in court yeah, every other state. Um. Usually the both sides have to agree on it being admitted or um. The judge has to say, yeah, we're gonna admit this one, right, Yeah. And federally, the judge decides whether or not they're going to admit it, right, And I guess state judges kind of follow that federal ruling of polygraphing. Yeah, And it's sort of a crapshoot if a federal judge is gonna allow it or not. There's no precedent really to where they say we have to or we don't have to. Right. So, what are the problems with this um? The problems with a polygraph um or that it's subjective, Right, that's a big one. But also because there because it's subjective, you can get what are called false positives and false negatives. Yeah, and you don't want that because then the test itself is just not valid. Right. Uh. But I mean that a lot of people use that as evidence that polygraph polygraphy shouldn't be done at all, that it's not valid. False positive and polygraph thing is when you find somebody who is deemed deceptive but was telling the truth. False negative is when somebody who wasn't telling the truth UM is deemed truthful. Like Gary Ridgeway, the Green River killer. They had him for a little while and gave him a polygraph and he passed and they let him go and he went and killed a bunch more women. All right, that's right. I didn't know that. Actually, Yeah, there's also the uh. You know, the federal government is the largest uh consumer of these exams, and if you work for the federal government, you've probably had one to get the job. But you can't do that in the private sector thanks to the Polygraph Protection Act Employee Polygraph Protection Act in the late eighties, they said, you can't force your employees to do this US. You can request it, but if they don't want to do it, you can't fire them because of it. You just can't do it, right, not in private land, right unless you have a contract with the government, and then that's not valid. But yeah, the the federal government is the largest opponent to him in court, but also the largest consumer. And imagine that, UM. And there's been a lot of cases that shaped its admissibility or not. But the polygraph it seems like it's kind of honest way out. I wrote an article about UM M R I being used as lie detectors, and that's starting to kind of come into fashion the more we start to understand, like how lies are born in the brain, being able to see it and saying this is the pattern that will happen. UM. If this person is lying and then that pattern happens, they say, what, we know you're lying. We just saw that live form in your brain. That makes sense, yes, But at the same time, people who understand MR eyes say, is way too early to be doing that. And even if we can do it with accuracy, there are a lot of moral and ethical questions to it as well that we need to address. First always uh and then penile plus demography. What's that? So? Remember the the UM newmeographs that go around the chest and the abdomen. Imagine one of those that goes around the penis and it does the same thing. It the text changes in contraction and girth. It's a perfect way to put it UM and it's used to detect arousal. They use it for UM sex offenders. It's under at least as much attack as regular UM polygraphs. But I wrote this blog post called UM using science to root out late in homosexuality among homophobes. A study at U g A used UH penile pleas plesismography UM to find if anyone who they had deemed homophobic be came aroused to inexposed to homosexual pornography. Yeah, it's it's one of the better posts I've ever written. Cheese, all right, that's our future. I guess peno pleathismography for everyone, everyone with a penis at least and then chuck. Lastly, I want to encourage everybody, if this has piqued your interest about lie detectors, to go watch the shoe Court shoe store job interview clip from Mr Show on YouTube. You remember that one. It's very good weather friend Paula Thompkins and he has a breakthrough. Was seeing that one? Yeah, yeah, good old p f T yep. And that's it for lie detectors, right, Yeah. I want to take a test. If there's someone in the Atlanta area that administers these and would be willing to give me a lie detector test, I would love to do that, Okay, and I'll watch yes UM as long as I can, you know, approve the questions or not approve them. But I don't want to be like rooted out as some miscreant. That's a little late for that. Just keep it above board. UM. If you want to know more about lie detectors and play with some Lie detector flash animation, you can do that by typing in lie detector on this in the search bar on how stuff works dot com and UM, that means it's time for listener mail. That's right, Josh. This is from Brad and Brad. If you remember, we had a list of suggestions from a listener not too long ago that thought our podcast could be a lot better if we changed a few things. Brad has some suggestions of his own of how we can make the podcast better. We should both have nicknames zazz up the actual name like welcome to stuff you should Know with j C and the Dingo, sit back while getting a big helping of knowledge from Chucko and the Duck. I second the suggestion to remove the personal anecdotes should be moved to a separate podcast called the Josh and Chuck Memoirs. Daily one hour podcasts can recount your lives from birth to present, focusing on depressing stories that are marginally factual. It's in development, Chuck, please your raise your voice one octave, Josh lower yours one octave. What okay? So now this is how I talk to the opening of the podcast should be a description of what each of you ate that day and the number of trips to the bathroom. This allows the listener to keep track at home. Hedgehogs, brain surgeons, arcades, and Bolivian politics are underrated, under sorry, underrepresented on your podcast at least should be about these subjects. Do not exclude listener mail. Instead, create a quieter audio track reading the listener mail and overlay it on the rest of the podcast. That way, listeners can hear both the mail and the main content at the same time. This is a pretty good idea. Why not set the pod we literally driving people in Spain? If we did that, why not set the podcast to a backdrop of tribal drums and jungle animal noises would give it an exotic feel. That's over the listener mail track, over the whole thing, So that'd be three tracks deep. Yes, and it would lead to suspense for the listener to wonder if you will be eaten by jaguars? Uh. And it was clear from the podcast on Mummies neither of you had ever been mummified. Please refrain from explaining topics that you don't have personal experience with. And then the final suggestion, just retail episodes of this American Life that went that last one went down like the Dave Glitterman top. Finally, so that's Brad, Thanks brand. Those are all great ideas. Three tracks all in one, streaming at once together listener mail quietly to podcast and tribal drumming and jungle noises. Yes, um, let's see. If you have access to a polygraph and want to hook chuck up to it, let us know. You can let us know on Facebook at facebook dot com, slash stuff you Should Know, You can tweet to set s y s k podcast, and you can send us a regular old email at stuff podcast at how stuff works dot com. Stuff you Should Know is a production of iHeart Radio's How Stuff Works. 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