The Truth about Lie Detectors

leads to our listener mail. This listener mail comes from Boris or if you wish, Bobcat, and I do wish, So this listener mail comes from Bobcat, who says, hello, beloved tech eas First of all, I have to say that I really appreciated the rant and other outbursts of

skepticism in your ghost Hunting Technology episode. That has been a profound absence of critical thinking and evidence based positions on various issues coming from the media lately, and your show has definitely made me feel as if there's hope for rationality and non wackiness. So kudos you've made at

least one listener as happy as pie. If you're considering doing more podcasts with related undertones of skepticism, I suggest that you guys consider taking on things like radiometric dating technologies as well as lie detectors and the technology of spying. That is, how some believe that the government may be watching us and how they actually do. Also, during the sci Fi Movies podcast from before, you brought up doll

House in passing still can't believe it's over. Why cover movies for a podcast, not do TV shows and then rub it in our faces by mentioning Dollhouse. I expect this gross malfie essence to be corrected as soon or malfeasance, I guess I should say my brain is not working. Should should be corrected soon. And with one of those annoying listener mail announcements from Strickland, thanks for maintaining your high standard of podcast. Yes, except for the fact that

I mispronounced malfeasance. Um well boris thanks a lot. We actually decided from this email to take one specific UH suggestion, which was the light detector suggestion. I thought that was an excellent suggestion. We can talk about how they work and how they do not work, because they do both at the same time. As it turns out, I'm sorry, I was still thinking about pie. Yeah, I was still

thinking of Malfie, Yes, and so uh in suburbia. But you know, you know, once in a while I dropped a bomb like that and then I beat myself up over it for the next like three months apparently. So anyway, yeah, let's talk about let's talk about polygraphs. Light detectors. So those those highly calibrated machines that it takes you know, a train forensic psycho physiologist, uh, weeks to learn. Yeah,

yeah you could. It could take you up to fourteen whole weeks to learn how to operate one of these things. All right, before we get too far, let's let's let's make some things very clear. First of all, light detectors do, in fact measure things. They're not just it's not just a box with some little pens that scribble on a paper randomly. It's not like it's it's um uh, you know,

just a fake tool. Um. What they do is they measure physiological responses over a set period of time, the set period being whenever you turn the machine on and whenever you turn the machine off. Um. But it does this through three main methods. It measures your respiratory rate. That would be uh, the respiratory Right there is Chris breathing heavily into his mike getting it's just if any of you found that creepy right tech stuff at kustaphors dot com. I know I will be. And then it

also measures your pulse rate. It has a pressure cup on your arm. Oh my god, hey, you know I'm okay. I want as as a as the person who is sitting here in the studio with Chris at this time. I can't wait to see what he has to do about this one. I got nothing for this. Third. The third thing it measures is galvanic response, which technically is

um sweating. And yeah, Chris is always sweating buckets, so it's kind of hard to tell from one moment to the next if he's actually, you know, trying to display something, if he's trying to to illustrate a point. But that's just as he's not really sweating. So they do this through various methods. There's like a there's one that will be sensors that are placed around your chest to measure your your chest expansion and contraction. Wise, your breathing would

be the respiratory rate. Part that would be the respiratory rate. There's a pressure cuff placed along one arm that measures the pulse the blood pressure right right, and then there are electrodes attached to the fingers to measure the galvanic response that the amount of sweat. Yes, okay, so they have a bucket underneath the tables, you know, if it gets out of hand. Yeah, when Muggsy comes in, they're like, okay, we got us weather, Let's let's put a bucket under there.

So these are always measuring these changes in the rates. They have to establish a baseline first, and any change in any of those three uh factors will result in a needle on the paper scribbling something um so that you'll see you can actually see where the changes happen along along the set time period. I think we've all seen a movie or TV show where the you know, they've done that close up shot and little needle going right,

the needles starts shaking back and forth really crazy. In case any of you can't hear that, you know what, we should just leave it to Liz to put in the little scratchy sounds, because I bet that picks up a lot better than you scratching on your laptop. I don't know. They can pick up footsteps outside the studio, that's true. We have her bigfoot lurking outside our studio occasionally anyway, but at any rate. Okay, So so yeah,

these it's not just one line of data. It's actually uh several lines of data because you get the you get one essentially for each um uh factor. So uh, there are three different needles measuring it, and ideally you would be able to look at the three different lines and be able to tell when there was a major

uh change in someone's physiological response. Well, there's there's sort of a hypothetical basis on which you could say if somebody was lying, you would expect them to be more stressed out than if they were telling the truth, preventing the truth from coming out. Right. That's that's what the whole, the whole basis of of polygraph is is. That's the

foundation for the polygraph test. The foundation for the polygraph test is an assumption that if you lie about something, you will your body will respond, will engage in the fight or flight response. Not to take something from our sister podcast stuff, you should know, that's their favorite phrase or it used to be anyway, but the fight or flight response tends to pop into play whenever you are trying to to conceal something. At least that's the theory. Now.

If this were to hold true, if every single person in the world were to respond in a similar way whenever they were trying to be elusive or lie about something, then the light detector test might actually work if everyone responded the same way. But we're human beings. Turns out we all have different responses to the same sort of sensory input. Some of us, uh get very anxious at times,

including myself. There are there are certain situations where I get very very anxious, and um, I'm certain that if I were ever brought in to be questioned about something, I would be very anxious about it. Not because necessarily that I did something. I'm not saying I did, and

I'm not saying that didn't. I'm just saying that, yeah, But in either case, even if I were completely innocent of it, I know that people asking me these questions would make me nervous and my body would react in such a way that, uh, it would be very difficult to say that a reading that you got for me would be, would would indicate a live versus truth just because I would be anxious no matter if I had

done it or not. Uh. Conversely, there are people out there who are consummate liars, and either they are delusional and actually believe the things they're saying, they're sociopaths, they don't care what they're saying, or they've trained themselves to not give away these physiological responses so that it's very difficult to tell whether or not they're telling the truth.

Everything looks like the truth. It's kind of fascinating to think that there are actually people that are you know, that actually believe that what they are saying is true, even when it's you know, a patent lie. Yeah. Um. But you know, if if somebody is delusional about that and believes that what they are saying is true, then they're not going to register any kind of response like that. They believe it to be true. And as time passes, it's it's easier and easier to believe a lie. Uh.

I mean uh. And and in some case when I'm saying lie, it may just be an exaggeration. For example, if you think about something that happened to you in your childhood and you tell the story about it, and uh, it can. It's one of those things that I've mentioned this before. It can build over time, like you elaborate the story and you might exaggerate one fact over another, or you might add in a little thing that that

didn't necessarily happen, but it makes the story better. And upon retellings and over the passage of time, you might actually come to believe that that is actually exactly how it happened. And then if you were to review, say a film of it or a video of it, you might be shocked to see how different the real event

was from the way it was in your mind. If you've been given a polygraph test and you were asked to relay that information under the polygraph system, uh, it would show that you're telling the truth because you're you're saying what you believe. It's not it's not a there's no magic in the box that allows it to determine

what is really true and what isn't. So let's talk a little bit about the process of a a graph examination and kind of explain, you know, how how these examiners build a routine so that they can try and and track lies right now. Um. Actually, when I was commenting earlier, when we got started about the forensic psycho physiologist,

I was hoping to say it without tripping that time. UM, those are the people who who like to UH or who are who like to be known that with that it is their professional UH title, I guess, but they are the people who give the polygraph tests and really a professional forensic psycho physiologist. If I don't look at

the words make them out easier. Um, they are. They are generally going through some kind of professional training UM, such as the ACCTRON International Academy UM, which is accredited by the American polygraph Association and certified by the American Association of Police Polygraphists Polygraphists. People who have polygraphs. Polygraphists sound like people who have more than one graph. Um.

I'm on a monographists myself. So if you so, If you were going to to become a forensic psycho physiologist US, you would need to UH to have a baccalaureate degree or at least five years of UM investigative experience and an associates degree UM. You would need to go through a certified course which includes, among the different categories you would need to study or psychology, physiology, ethics, history, UM, question construction, UH, speech analysis, chart analysis, text and test

data analysis. And you would also have to uh, you know, go through a series of exams to you know, on actual cases in which a LIE detector tests or I should say polygraph is being used. Um and the th are reviewed by professionals. So, uh, this internship can although the program is sort of short, that the internship can take from eight months to a year. According to the article we have on the website about how lie detectors work, Yeah, it's actually a very good article. I do recommend that

you read it. Um. So that all being kind of beside the point really when you get down to to what exactly is going on with lie detectors. But I just wanted to point out that that that there is some that the people who are actually doing this for say a police department or another law enforcement agency, go through training on how to interpret what they think is coming out of the machine. Right. The problem is that again the very foundation of what they do is faulty,

so built on a false premise. Ultimately it's built on a false premise. I just wanted to talk about how the process works. Okay, So let's talk about the test itself. Okay, So during the test itself, what would happen is the examiner would you know strap ian um. So let's let's let's say that that I Jonathan Strickland. I'm the subject

of this polygraph examination. The first thing that would happen is that we will Usually you get a few questions at the beginning that are supposedly to form the baseline so that the questionnaire can see what your level of anxiety is, just based upon normal questions, nothing that necessarily has anything to do with what they brought you in for.

They want to see basically what's moving the needles when they tell it, say or ask you versus what isn't moving the needles, and they can get an idea of how you're gonna behave right if you're If you're already anxious, then this would theoretically at least let them know. Okay, this guy's kind of a nervous nellie, so uh uh, anything that hits this level doesn't necessarily mean it's a lie, because this dude's just quivering in his boots, which is

exactly how I would be. I'm not gonna lie I'm about that anyway, So they would ask me a series of questions, supposedly to create a baseline. Now this is debatable whether or not this actually, you know, may any real difference. Next, what they would probably do is ask a control question, and this would be a again a simple question where it's just to uh, to measure your

your response. And then they would alternate that with a question that actually relates back to what they're looking into, right, and that would that would be why they ask the people who are training to work with polygraphs to learn about question construction, because they want to learn how to phrase uh different topics in ways to see if they can get a response from me. Yeah, so you get you get your design questions or what they're called, were the ones that have to do with your actual what

the purpose for the polygraph. So let's say, look, the first question might be uh, um, is your name Jonathan Strickland And I would say yes, And then the next question might be I don't know, and then I'd pee myself. But the next the next question, my be might be um more pertinent to whatever the matter is. For instance,

like like uh, were you in the Buckhead neighborhood? On Tuesday night, and then I would say either yes or no. And then if they suspect that I was there and I said no, they would look at the chart to see if the response on that question, UH was measurably different from my response to the control questions, because if if I'm answering the control questions honestly, and they should be able to to know that, because the control question should be obvious, right, it should be very obvious questions

like are there two people in the room with us, and you'd say yes or no? UM. If you are lying to an obvious question, then they can tell pretty quickly if you're going to be able to to fool the polygraph UM, which by the way, is very possible. So they alternate these questions. They will ask a control question now and again just to make sure that that they're reading the results correctly, and then they will ask one of the design questions to see if you are

telling the truth or not. UH. You can get through an entire polygraph lying your butt off the whole way through, and if you are able to control your responses or you're able to boost your responses to control questions to show that you are a nervous, nelly. Either of those are going to make the results unreliable. They're not gonna be able to say this guy for sure was lying

or or was telling the truth. So for instance, that they asked me, is your name Jonathan Strickland and I said yes, but I was able to, uh, to provoke myself into reacting in a more um well heightened way, it would indicate that I had lied on that even though I told the truth. Um, and this could all be very I can manage to do this on my own. So in other words, I could fabricate it as if it looks like it looks like it's a lie. And then the next question they asked me, where you win

Buckhead on Tuesday night? And I say no, Um, I could just relax a little bit and then it will come up as not being a lie, and then they'll they'll look at the results and say, well, according to this, I mean, we asked him this control question. He told the truth, but his response was off the charts. Then we asked him this question and he said no, and

his response was calm, clearly, he's just nervous. We can't we can't rely on this as as information to establish whether or not he's guilty, or or if he's telling the truth or not. Um So, really, when you get down to it, once you understand that, you realize the polygraph is not a reliable tool for telling truth versus lies. That doesn't mean that the polygraph isn't useful if you are willing to use some psychological bullying to try and

get a confession out of someone. In fact, it's incredibly useful if you want to try and get a confession out of someone, and as long as that person believes that the lie detector is doing its job and is working properly, it's it can be incredibly effective at getting a confession. It's but it's almost like a confession under dure us if you think about it, because the person is being fooled into thinking this device is doing more

than it really is. Well, how are you How are you going to fool somebody into believing that it actually works? All right? What could they do? Here's here's a good example. This is not necessarily how everyone does it, but there are police, state law enforcement officials who have done this or examiners who have done this. Um you do a very simple card trick, but you don't present it as a card trick. What you do is you you present

the person who's being questioned. You present that person with a deck of cards and say, pick a card, look at it, memorize it, put it back in the deck, you know however you want to do it. And then you deal the cards out face up, and you just tell the person, uh, just say that it's not your card, whether it's your card or not, say it's not your card. Okay. So each card that comes up, you're saying, no, that's not it, No, that's not it, till you go through

the whole deck. Then the person goes back to supposedly look at the results on the polygraph, comes back and then says, our core into the polygraph, this is your card. And they hold up the card that you picked. And then you're convinced, oh my gosh, not only does this thing work, it can actually work to the point where it can it can tell the difference of one response

out of fifty two questions. Now, in reality, the examiner has just used a very very basic card trick, and it's a it's there are many different ways of doing a card force where you forced someone to pick the card you want them to pick, or you don't force them. You just you manipulate the cards in such a way that you know what card they picked. Easiest ways just pay attention to what card is on the bottom of

the deck, and then you cut the cards. You put you put the person's card they chose on the top of the cut. You cover that up. Well, the card that was on the bottom of the deck is gonna come immediately before the card that person picked, So you just look for that, like if it were the three of Hearts, you look for the three your Hearts. Next card that's gonna be the one that the person picked. I just I just did a big reveal on magic tricks. But that's a very basic one. So lots of YouTube

videos out there that show how that's done. But anyway, you in this case, the examiner is gaming the system. The examiner already knows what the card is, does not need to look at the light detector at all. In fact, the light detector probably wouldn't even help at all and figuring out which card this was unless someone was just that hyped up about, oh my god, that's my card. No, that's not it. I mean, unless that were to happen.

The light detector wouldn't help you. But by establishing that the light detector is so sensitive and accurate, you have now built into the person's mind that this thing is gonna catch you if you lie. And then you start the questioning, and since the person now believes that if he or she lies, it's gonna be instantly recognizable, they might actually move ahead and just confess. So you've skipped the whole process of having to do a light detector

test in the first place. You've scared the person into confessing a crime. Now, of course, if the person is innocent, that's not gonna help at all. You know, you're still gonna have to go through the whole thing. Um, it's only if the person is guilty and willing to confess, if they if they don't realize that it was all a trick to try and gain their confidence. That's just

one method. There are other ways of doing the same sort of thing, where you tell a person to lie and then you show them the results on the lie detector and say, see, here's where I asked you to lie, and you see where your response is, and that could either be a legitimate test that they're showing them, or it could be a pregenerated test where you're just showing them some lines and saying, see, see where I asked you to lie, and you see these squiggles here. Those

may or may not be your squiggles. I'm just saying those aiggs right. Yeah, if you're like, no, obviously Jane wasn't here lying. She's a terrible liar. I'm much better, But yeah, they're It's it's essentially deception, is what it boils down to. And that's not to say that every examiner feels that this is necessary, or that every examiner even thinks that what they're doing has no merit. I'm

sure most of them think that it is. Uh, it is a completely legitimate practice, but the fact remains that it's it's really it's just measuring your physiological response, which is different for everybody. Yeah. Yeah, there are there some things that people try to do to avoid giving themselves away, So just taking sedatives or biting their tongue or sticking attack in their shoe. There there's lots of other very simple ones. Just simple breathing exercises can help you stay calm.

And like I said again, if you if you take it so that you maybe you tense your muscles a bit when you are when you're truthfully answering a control question. If you tense your muscles that and you just increase your breathing rate a little bit, that's gonna be enough to boost your your pulse and to change the respiratory reading to uh, to start fouling up the um the results. It is not hard to learn how to fate, how to how to fool a polygraph, or at least fooling

is probably the wrong word. How to make the results unreadable, essentially, because if you make it so that it looks like you're lying to answers that are obviously the truth, they can't rely on the test as a whole. Yeah, And I think that's why, uh, it's so controversial even now after decades of being in use, and why so many jurisdictions won't allow polygraphs to be submitted, and there's still some that will, and some of them will only do

it upon the order of a judge. Like in some jurisdictions, a judge can say can allow, has has discretion to allow or not allow lie detective results. Um, I I think it's it's I think that using them in any case in a in that sense like as evidence, is terrible. It's just a horrible idea because it's already been proven to be unreliable. You can beat it if you know how, and even if you don't know how, but you are anxious, can be falsely you can give off false positives. Um.

And here's another good example. I meant to mention this with the whole control question versus the the real questions. So part of the problem is that you can never really establish a good control versus real question because the control questions aren't going to have the same emotional impact as the real questions. Okay, so, like a control question

might be do you live at such and such address? Well, there's no emotional attachment there, there's no sense of risk, there's nothing like that, and you you could just say yes. But if they say did you kill Mr so and so blah blah blah, well that that's definitely got an emotional attachment to it, whether you did it or not. Just the accusation alone is enough to provoke the fight or flight response in most people. Maybe not even most,

but in lots of people. Most is probably too too vague word but I would I would think that a lot of people would respond very strongly to that question whether they had done anything or not, because it's an emotionally charged question unless you were able to create control questions that were also emotionally charged. Uh, you can't really say that's a baseline. You know, it's like how was your day? Oh it is good? Good? Did you skin this person alive? And then wear that as address that?

Two different questions, two different levels. For some of us we can casually answer yes to those, but others, you know, would have a bit of a reaction to that. Sometimes you frighten me. I just wanted you to to do that. Well, hell, you know what springs right around the corner, and fashion time is coming up great at any rate. So polygraph tests, uh, I think you can safely say are great for measuring a physiological response, not great at at ascertaining truth versus lies.

So there, it's a misnomer. Really, it's more of like Tyler was saying, our our guest producer for the day. Uh, it's more of a stress test than a than a lie test. Um. Do you have anything to add to that? No? Not really. The fact that some some pretty major cases kind of came down to lie detector evidence making a big difference. Yeah, it's a little hard to imagine that,

but um, it's true. But in in several of the cases, just because someone passes a lie detector test doesn't mean they're innocent, And just because someone fails it doesn't mean they're guilty. Well, it also if they fail it, they might be guilty. If they pass it, they might be innocence. So even in cases where lie detector tests were entered into evidence, usually there was other evidence that really contributed

to a person's sentence of guilty. Um, that doesn't necessarily mean that no one has ever been falsely imprisoned because of a lie detector test. I haven't done the research on that. I would imagine that it's probably happened, which is unfortunate, but uh, it probably doesn't happen A lot

still shouldn't happen at all, I know. But anyway, Yeah, but I'm glad we tackle this one because it's, uh, it's fascinating to think about it, and it's some The thing that makes this so different from the ghost Hunter Tech episode is that you know, it actually does more or less what it's supposed to, but it's just so unreliable that you can't count on it. Yeah. Yeah, like I said, there is you know, a legitimate reason for wanting to use it, right. It it does measure things.

It's just like I said, the premise that it's based upon it itself is faulty. And that's the problem is when you when you're when you have a faulty premise, everything else that follows can't be relied upon. And again talking about critical thinking, so that's another great um example. And yeah, if you guys have other critical thinking kind of of topics you would like us to tackle, let us know. Now we should also point out some people have been suggesting things that really don't fall into the

tech field. Uh. And this, since this is tech stuff and not skeptic stuff, we can't just tackle anything, as much as I would love to do that. But we do have a sister podcast called Stuff from the Science Lab that just went live not that long ago. And um,

I'm sure they'd talk about scientific Yeah. I don't know what their email addresses off the top of my head, but as soon as this, by the time this goes live, um, I will I be sure to make a blog post that points people in the right direction, because I think that that podcast would probably be the best place to tackle skeptical matters that are non technology oriented. I mean,

I'm still going to take the tech ones. I will find them tooth and nail, but if it's not tech related and you still want to hear about it, it would be a good choice. So but that brings us to our second round of listening along. This listening mail comes from Jason from Maryland, and he says, Hey, guys, I read this and it reminded me of your podcast a bit ago about easter eggs. I hope all is well. A crazy easter egg popped up on airfare search site

kayak today. If you try searching for one way flight from Sydney to Los Angeles to place on September twenty two, two ten, you'll get the fictitious flight featured on a mysterious TV show called Lost, which is true. You'll do get the Oceanic Airways flight. Um. I've never actually seen an episode of Lost, but I went ahead and tried this anyway and it did work. Yeah. Cool. I then was mauled by a polar bear. I have no idea what that's about. Yeah, I don't either. I haven't watched

the show either. We're lane if you want to write and tell us how lame we are tech stuff at how stuff works dot com. Remember when we get the blogs, we get the live show every Tuesday one pm. Uh. I hope you guys are are tuning into that. It's been a really fun experience so far. We've we've managed to to to alienate Apple fans and when does fans alike? All right? I hope we can continue. I think Lennox is next. Just you know, it all depends on what's in the news. We'll see, so tune into that. Read

the blogs, check out the website. Check out this article on how light detectors work. It's a, like we said, a very good article, and we will talk to you again really soon for more on this and thousands of other topics. Does it how stuff works dot com and be sure to check out the new tech stuff blog now on the house stuff Works homepage. Brought to you by the reinvented two thousand twelve camera. It's ready, are you