11 ms·

How to Beat a Polygraph Test

211 points by andrewl 12y ago

tptacek 12y ago
I've never taken one. Question: if you're fundamentally convinced that polygraphs are hokum (as I am), do you actually need any tactics to "beat" them? Or can you just ignore them and handle the interview the same as you'd handle any other interview, and just sort of smile and shrug when the "operator" tells you the machine spat out some significant result? ("Huh, maybe I just had to burp.")
- fnordfnordfnord 12y ago
  >do you actually need any tactics to "beat" them? Maybe. Tactics aimed at fooling the machine are really only to bolster the confidence of the person being tested. It's not the case that you're playing against a machine though, the machine doesn't "do" anything; it's a game that you're playing against the examiner.
  - tptacek 12y ago
    Right. But polygraphs really are hokum. If you don't doubt that fact, what advantage does the examiner have? Is it that I'd have to account for the fact that they might irrationally believe in the machine, and adjust my performance to fit that irrational belief? I think what I'm getting at is that the notion of "cheating" or "beating" a polygraph seems like it dignifies the procedure. It's a little like "beating" a psychic medium, isn't it?
    - fnordfnordfnord 12y ago
      What makes you think that the polygraph examiners "believe" in the machine. I'm pretty sure most of them don't. I wouldn't always assume good faith on the part of the examiner, either. In the common use case of culling the herd of police job applicants, polygraph examiners are there to provide a way to arbitrarily reject certain applicants. So, in that case, the applicant basically has to make the examiner "like" him. It's better than "beating" a psychic medium because there is often a real, valuable prize to be gained (ie: a job). As far as I am concerned, even submitting to examination dignifies the procedure too much.
      - tptacek 12y ago
        If the polygraph examiner doesn't believe in the machine and the candidate doesn't believe in the machine, I'm a little lost as to how the examiner has any advantage, or why you would need any special techniques to "beat" the process. To be clear: I don't think you do need those tactics, but I'm asking, not asserting; I've never taken a polygraph.
        nitrogen 12y ago
        Based on other comments in the thread and other things I've read, it seems like the polygraph machine serves only to intimidate the interviewee into wearing their emotions on their sleeve, and the real purpose of the polygrapher is to try to read body language. It also sounds like polygraphers may think they are reading someone, but in actuality just injecting their own bias. I have also never taken a polygraph, but maybe the process to beat is the bias of the interviewer, not the machine.
        tptacek 12y ago
        Right! So isn't it weird to see us proposing things like new tricks to beat the machine? What machine? Can't I just imagine it's a Magic 8 Ball instead? Would we propose tricks to beat a Magic 8 Ball? No!
        kelseyfrancis 12y ago
        > What machine? Can't I just imagine it's a Magic 8 Ball instead? I mean, measuring perspiration, pulse, breathing, and movement is perhaps a step above a Magic 8 Ball. I too am entirely doubtful that anyone can reliably detect deceit with those measurements, but it's hard to have a nonchalant attitude of "this is just a silly game" when you're connected to devices that do in fact actually measure those things.
        Canada 12y ago
        The presence of the machine changes the nature of the interview. It's like how being interviewed on the phone at home and being interviewed handcuffed to a table with a gun your head are different. It really doesn't matter much if the interviewer actually intends to shoot you or not. The mere presence of the prop induces stress making it difficult to think clearly and avoid being manipulated by the interviewer. To succeed in the situation your mind must be prepared to deal with the gun or the handcuffs or the polygraph. I doubt many people are able to simply ignore them.
    - doorhammer 12y ago
      For me it would be a matter of personal strategy. Basically, is standing on principle the most strategic thing I can do given my goals in the situation that left me on the receiving end of a polygraph? Even if my strategic goal is to show that a polygraph is meaningless, being able to pass or fail one at will could be really useful to that end. The odds seem pretty low that any job or clearance requiring a polygraph would let you get by without one, even if you displayed an extensive knowledge of them and how they're flawed. Personally, if acting on principle, I'd probably just not want to work at a place like that to begin with. Of course, I'm sure there are some highly sought after individuals that could get by with that, and it probably depends on whether or not the organization you're engaging with views the polygraph seriously or as a relic on its way out. If it were something to do with legal proceedings, I'd have to talk to a lawyer first, and see what was in my best interest. As far as term semantics go (which I think are important), maybe "manipulating" would be a better word than "beating" or "cheating" edit: The sibling poster also has a really good point about everyone possibly knowing it's a sham, but using it as a tool to get rid of people they want to get rid of. That might be more likely than all my speculation
      - tptacek 12y ago
        Ok so I think we may be talking past each other here. I'm not arguing about the legitimacy of polygraphs. They're hokum. I'm keying in on things like "being able to pass or fail [a polygraph]". "Able" to "pass" or "fail"? Would you say the same thing about being able to pass or fail a psychic palm reading? I feel like I'm missing something, which is why I keep asking.
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    - Cushman 12y ago
      > Is it that I'd have to account for the fact that they might irrationally believe in the machine, and adjust my performance to fit that irrational belief? Well, yeah, wouldn't you? I mean, the fact that you're being given a polygraph implies that your interrogator believes it has some effect that benefits them. And if you're completely convinced that that isn't true, meaning the human-with-polygraph is not more reliable than an unaided human, that still leaves the possibility that the human-with-polygraph is worse in a way that affects you. If there's a possibility for the device to convince your interrogator that you're being deceptive, but you're honest, you're taking a risk unless you attempt to avoid causing a false positive. Conversely, if there's a possibility for the device to convince your interrogator that you're being truthful, and you're deceitful, you're missing out on an advantage unless you attempt to cause a false negative. There's no case where your interrogator is better off, so your premise isn't invalidated; the polygraph itself is still bunk. But it's your interrogator's trust in it which has created a relative advantage for you if you play along. The exact same applies if they show up with a "psychic", although it might be harder -- or easier -- to manipulate.
- moron4hire 12y ago
  The problem is the operator is trying to unnerve you and embarrass you, specifically to fluster you. They don't just just ask you the questions they're interested in. They ask you about your personal sexual habits and other things designed to trigger an emotional response. It's all just a sham. The more honest of a person you are, the less likely you are to pass the polygraph on your first try. And the only way the polygraph works to catch out liars is to use the shame of the situation to coerce a confession out of the person. Say they ask you "have you engaged in homosexual behavior, especially under the age of 14?" Most people I know, given the situation, will blush. And blushing is basically all a polygraph can actually measure. So now they start berating you that you lied, and if you continue to insist you didn't lie about that particular question, they say it means you lied about a previous one. The only way to pass a polygraph is to know what they are like and just get through it. Honest people and liars both just need to stick to their stories, regardless of what the polygraph is saying, because eventually they will just fail you and schedule you for another one. Repeat until you've been through it so many times it doesn't phase you anymore. Then their job is done, their job being, "it wasn't my fault if you turn out to be a spy."
  - tptacek 12y ago
    Sure! But there are lots of situations in which a counterparty in a discussion has an off-putting advantage (see: every job interview), and yet we don't generally offer advice to candidates along the lines of "tense and relax your anal sphincter repeatedly" or "visualize your happy place on target questions and your worst nightmare on control questions". Is where I'm going with this clear? I feel like I'm just confusing everyone with this line of questions. I'm literally just asking: If I was given a polygraph tomorrow, knowing what I know now (in fact having conviction about what I know about polygraphs), wouldn't a reasonable strategy be to ignore any polygraph-specific advice, and manage the process the same way I would if there was a Magic 8 Ball adjudicating it? I know there are differences between the plastic toy and the fortune-telling billiard-ball, but are they meaningful?
    - moron4hire 12y ago
      A magic 8 ball would be just as effective of a prop in the play that polygraph operators play.
justincormack 12y ago
The US is pretty much the only country that uses polygraphs with any frequency. In Europe [1] they are not used. The US needs to stop using the bogus devices. [1] http://en.wikipedia.org/wiki/Polygraph#Europe http://en.wikipedia.org/wiki/Polygraph#Europe
- tptacek 12y ago
  They're mostly discredited here as well. Criminal defendants can't be forced to take them. In virtually all states, defendants can suppress polygraph evidence. In some of the states where polygraph evidence is allowed (by consent of defendants), the defendants apparently also get a civil cause of action against the polygraph vendor. Unfortunately, we still use them as part of a hazing ritual to get clearance for national defense projects. But the poster upthread is probably right that those kinds of projects aren't the ones you want to be working on anyways.
  - learc83 12y ago
    The interesting thing about polygraphs is that they can be an effective interrogation tool as long as the subject believes they work. (but then again so Santa Claus if the subject believes in him) For instance the interrogator says, "the polygraph says you're hiding something from me, are you sure there isn't something you want to get off your chest." The should however, be banned completely because the false positives are so high that we are crippling many of the agencies that rely on them. We're forcing them to drastically reduce their potential talent pool based on pseudo science.
    - rdtsc 12y ago
      > the false positives are so high that we are crippling many of the agencies that rely on them. Even worse than that, it selects for people who lie with impunity without any visible or emotionals qualms about it -- basically it selects for psychopaths.
      - sukilot 12y ago
jpmattia 12y ago
I would love to see polygraphs calibrated with a simple game of hi-lo. Pretty simple metric: Pick a number 1-1024, the questioner gets it right or wrong.
rquantz 12y ago
Given that the test is essentially measuring whether you respond to a question with an adrenaline burst, I wonder if taking beta blockers prior to testing can influence the results. That would be my first instinct.
- troisx 12y ago
  Some places test for drugs in your system along with the polygraph test since beta blockers are sometimes used to help beat the test.
zkhalique 12y ago
Well, this is the first thing I would think of, if I wanted to cheat on a polygraph test. Obviously I would just try to be more nervous at the control questions, to establish a baseline that wouldn't make the lies stand out. I'd imagine I'm lying on the control questions.
fnordfnordfnord 12y ago
The polygraph is quackery. They may as well just phone Miss Cleo and ask her if someone is lying. But good on them for pointing out how they are still used to coerce people.
USNetizen 12y ago
These are often used as part of required policy for the US federal government in certain types of security clearances. They seem to be used more as a psychological influence on the person undergoing the clearance than actually working to detect their deception, so I agree with that point in the article. Case in point, Snowden would have most likely had to undergo at least one of these polygraph tests for the cleared work he did and that didn't exactly prevent anything. Plus, people that are pathological liars can essentially convince themselves that something is the truth which these tests would rarely, if ever, pick up on as deception.
- a8da6b0c91d 12y ago
  I think the tests do in fact "work" in two senses. First, tons of people with "compromised" histories unsuitable for cleared work freak out and fail or even outright confess things they were concealing. That there's no real lie detection going on is irrelevant. As an interrogation tactic it still functions to some extent. Secondly, a lot of nervous nellies fail, even though they're squeaky clean. For a lot of the work where the tests are used you really do want to exclude people who can't keep their cool under a bit of pressure. If you freak out under the kind of questioning done, you're probably going to freak out in a way that reveals information if somebody starts asking about your work.
  - fnordfnordfnord 12y ago
    I disagree, and I think that polygraph tests filter out good people in favor of deceptive people and convincing liars. >For a lot of the work For a tiny fraction of the work. Maybe you underestimate the number of jobs that use this quackery.
    - a8da6b0c91d 12y ago
      > deceptive people and convincing liars. My point is that to some extent this is actually a necessary skill. You absolutely don't want people who can't keep cool and put out a bit of smokescreen and do some hand waving.
geomark 12y ago
I once had to take a polygraph to be considered for a security clearance. For various reason I didn't want it - I didn't want to join the group of social misfits I knew who worked on classified projects, I didn't want project security telling me where I could go on vacation and with whom I could associate (no foreigners), plus I had a few ethical objections. But at the time I liked my job (lots of great unclassified tech work), wanted to keep it, and needed to go along with my bosses' desires to get me cleared. The polygraph was administered by a strange guy from a three letter agency. I did the sphincter squeeze for every question. He said the test showed I was being deceptive. I thought that was the end of it and hoped my boss would leave me alone about it. But they called me back to do another one. This time I didn't do the sphincter squeeze. He said the test showed I was being deceptive. I don't know. I think the test just showed I didn't want to get a clearance.
- moron4hire 12y ago
  Polygraph operators are superstitious idiots, no better than TV psychics and climate-change deniers. They're a liability to the integrity of our security services, because they are physically incapable of performing a job that they certify has been performed.
- BorisMelnik 12y ago
  Many times they will make comments to get a reaction from you, such as: "Looks like you are telling the truth.." (even if it shows otherwise) If you look relieved or surprised, this might be something that they can use at a later date or further along in the interview. Polygraphs are 100% interpretation, they are not binary by any means.
  - pakled_engineer 12y ago
    Exactly, it's just an interrogation prop like when the East German police would have the fake telephone where they pretended to make calls to family/friends and verify your story, and had a button under their desk to make the phone ring so they could pretend to get just in time information to refute your story. Modern police will go into an interrogation with a decoy file folder full of random papers and then go through it claiming the contents refute your entire story and you'd better confess too. A standard polygraph trick is to switch it off, and then have a casual interview during the middle of the test. Then they claim they never switched it off and you've been lying the whole time as your casual results differ on the magic box. Props tend to work to get people to trip up on their replies even if the prop is just a box that randomly scribbles on paper with absolutely zero scientific credibility.
logfromblammo 12y ago
The only way to win is not to play. If you are ever in a position where you have to take a polygraph test, you have already failed.
- PhantomGremlin 12y ago
  The only way to win is not to play This is often forgotten. In so many situations in life, people think they must make a choice being forced on them, "yes or no" or something similar. Quite often the best choice is not to not allow yourself to play that game. Instead, learn to "think outside the box".
late2part 12y ago
This is a great article! There's a reason that polygraph tests are not normally allowable as evidence in court!
S_A_P 12y ago
To get security clearance you need to go through government sponsored auditing. They don't want any thetans to get access to state secrets.
Liquix 12y ago
It does seem much more similar to psychological torture than actual conclusive detective work...
- mellavora 12y ago
  you say that like there's a difference :)
mml 12y ago
When I was a kid, the polygrapher for the local maximum security prison was a member of the family church. He came in to school one day and did a demo for the kids. One memorable thing he said was that during an examination, there is only one lie detector in the room, and it isn't the machine.
- sukilot 12y ago
  And there is at least one liar in the room, but it isn't always the interrogatee.
snarfy 12y ago
One of my high school students who was an ex detective taught my class how to beat them. He said put a thumb tack in your shoe, and when asked each question, step on the tack slightly, enough to cause pain. A lie registers as a blip, but so does pain. If every question has a blip, they cannot differentiate.
- kelseyfrancis 12y ago
  > He said put a thumb tack in your shoe The examiner can just require subjects to remove their shoes.
- blumkvist 12y ago
  > One of my high school students who was an ex detective I read this many times. Can you expand on how a detective ended up as a highschool student? Sounds like a fun story.
  - snarfy 12y ago
    > One of my high school students who was an ex detective Should be "One of my high school teachers..."
loteck 12y ago
Never been polygraphed but I always wondered about an alternative to the "emotional control" approach to beating it that is discussed in the article. My alternative would be to trick my mind into not lying despite the question asked. So if I was asked "do you live in Chicago?" (i don't) and I wanted to answer yes, I would simply internally ask myself "is your name loteck?" and then respond "yes." I would ignore the actual question asked by the interviewer except to the extent I need to pick which internal question I would ask myself, of which I would only have 2. One for yes responses and one for no. Anybody have any idea if this would work?
- PavleMiha 12y ago
  I'm definitely not an expert in the area (never even taken a polygraph), but I highly doubt you could prevent yourself from getting nervous/agitated when asked a question about something you had to lie about. Don't think most people are that good at controlling their emotions, even if the question in your head is different you still know what the intimidating investigator actually wants to know.
- superuser2 12y ago
  Lying on control questions is not advisable. A polygraph would be conducted inside of a larger investigation which would, among other things, fact-check your claims by other means. These data would be considered in the interpretation of your polygraph results. Whether or not you live in Chicago is very easy to check; when they see that you are lying on control questions they will consider everything else suspect. In the contexts in which polygraphs are applied (i.e. security clearance, witch hunts within security services), simply being suspicious in this way is enough to cause the negative outcome (i.e. not getting the clearance, getting fired), so even if it might muddy the evaluation of your response to, i.e. "Are you a Russian spy?" it would still cause the negative outcome. It has no bearing on criminal prosecution, because polygraphs are already inadmissible.
  - dean 12y ago
    If you lie on a question that is easily fact-checked, and the polygraph shows that you told the truth, doesn't that just prove that the polygraph doesn't work? To my mind that is a simple test that disproves the effectiveness of the tool. It should cause a reasonable person to conclude that the tool doesn't work and should not be used.
caycep 12y ago
this is another version of the "machine learning" prob isn't it? the machine collects a bunch of basic physiological variables and makes a prediction, you just have to figure out what those variables are, whether it's hr, bp, etc
mml 12y ago
The ol' tack in the shoe trick was specifically noted as bunk by the examiner I knew, and the sphincter clench is semi-widely known. What I would find difficult with each of these tricks, is that you have to execute them during control questions, and not during "real" questions. Keeping track of when to clench or not while simultaneously trying to keep reality, and one's deceptions straight seems like it would be extremely hard to do under even mild pressure.
- kelseyfrancis 12y ago
  Plus you'd probably have to remove your shoes and there'd probably be a force sensor under your butt.
- sukilot 12y ago
  Not to be too much of a truther, but a polygraph examiner has no interest in admitting that their work is bunk.
  - mml 12y ago
    Perhaps he was a bit honest. These things happen sometimes.
jonathankoren 12y ago
I always thought George Castanza had the best polygraph beating strategy. "It's not a lie, if you believe it."
- mhartl 12y ago
  "Jerry, just remember: it's not a lie, if you believe it." https://www.youtube.com/watch?v=vn_PSJsl0LQ https://www.youtube.com/watch?v=vn_PSJsl0LQ
doorhammer 12y ago
If I recall correctly this book has an interesting section on polygraphs and a lot of other inaccurate methods and folklore around detecting lies and deceit: http://www.amazon.com/Detecting-Lies-Deceit-Pitfalls-Opportunities/dp/0470516259 http://www.amazon.com/Detecting-Lies-Deceit-Pitfalls-Opportu... It was really interesting when I read it, though it's a bit old now, so I'm not sure how much of the material needs to be updated.
faster 12y ago
When I was in high school I applied for a job in a VW performance shop a couple miles from my school. They sent me to the owner's neighbor for a polygraph, which surprised me but didn't seem like a big deal at the time. The guy was playing 'bad cop' from the second he answered the door, and said he was disappointed that I hadn't smoked pot on my way over because that makes reactions more visible on the polygraph. We went through his questions 3 times. The first time I just answered his questions, no games. The second time I tried to change my anxiety level sort of randomly (I had some experience with pretty high-end biofeedback equipment and knew how to affect the readings somewhat). The third time I used a breathing exercise that I was taught by a zen master to minimize my anxiety as much as possible. The polygraph operator was pissed, I decided that I had no desire to work for people who thought that was a good use of 45 minutes, and I didn't get the job. Everybody won, I guess.
DougWilliams 12y ago
It may be informative and entertaining to look at some of these videos on my website: http://www.polygraph.com/media http://www.polygraph.com/media And, if you are interested in more, read these essays: http://www.polygraph.com/index.php?i-don-t-teach-countermeasures http://www.polygraph.com/index.php?i-don-t-teach-countermeas... http://www.polygraph.com/index.php?the-lie-detector-is-bullshit-and-i-have-proved-it http://www.polygraph.com/index.php?the-lie-detector-is-bulls... And yes, I am the Doug Williams who is the subject of this article...
jakeogh 12y ago
Excellent resource on the pseudoscience of polygraphs: https://antipolygraph.org/ https://antipolygraph.org/
beedogs 12y ago
Polygraphs are about as useful and effective a tool as water-dowsing rods.
myhf 12y ago
There's an incorrectly joined infinitive in the second sentence.

211 points by andrewl 12y ago

I've never taken one. Question: if you're fundamentally convinced that polygraphs are hokum (as I am), do you actually need any tactics to "beat" them? Or can you just ignore them and handle the interview the same as you'd handle any other interview, and just sort of smile and shrug when the "operator" tells you the machine spat out some significant result? ("Huh, maybe I just had to burp.")

fnordfnordfnord 12y ago
>do you actually need any tactics to "beat" them? Maybe. Tactics aimed at fooling the machine are really only to bolster the confidence of the person being tested. It's not the case that you're playing against a machine though, the machine doesn't "do" anything; it's a game that you're playing against the examiner.
- tptacek 12y ago
  Right. But polygraphs really are hokum. If you don't doubt that fact, what advantage does the examiner have? Is it that I'd have to account for the fact that they might irrationally believe in the machine, and adjust my performance to fit that irrational belief? I think what I'm getting at is that the notion of "cheating" or "beating" a polygraph seems like it dignifies the procedure. It's a little like "beating" a psychic medium, isn't it?
  - fnordfnordfnord 12y ago
    What makes you think that the polygraph examiners "believe" in the machine. I'm pretty sure most of them don't. I wouldn't always assume good faith on the part of the examiner, either. In the common use case of culling the herd of police job applicants, polygraph examiners are there to provide a way to arbitrarily reject certain applicants. So, in that case, the applicant basically has to make the examiner "like" him. It's better than "beating" a psychic medium because there is often a real, valuable prize to be gained (ie: a job). As far as I am concerned, even submitting to examination dignifies the procedure too much.
    - tptacek 12y ago
      If the polygraph examiner doesn't believe in the machine and the candidate doesn't believe in the machine, I'm a little lost as to how the examiner has any advantage, or why you would need any special techniques to "beat" the process. To be clear: I don't think you do need those tactics, but I'm asking, not asserting; I've never taken a polygraph.
      - nitrogen 12y ago
        Based on other comments in the thread and other things I've read, it seems like the polygraph machine serves only to intimidate the interviewee into wearing their emotions on their sleeve, and the real purpose of the polygrapher is to try to read body language. It also sounds like polygraphers may think they are reading someone, but in actuality just injecting their own bias. I have also never taken a polygraph, but maybe the process to beat is the bias of the interviewer, not the machine.
        tptacek 12y ago
        Right! So isn't it weird to see us proposing things like new tricks to beat the machine? What machine? Can't I just imagine it's a Magic 8 Ball instead? Would we propose tricks to beat a Magic 8 Ball? No!
        kelseyfrancis 12y ago
        > What machine? Can't I just imagine it's a Magic 8 Ball instead? I mean, measuring perspiration, pulse, breathing, and movement is perhaps a step above a Magic 8 Ball. I too am entirely doubtful that anyone can reliably detect deceit with those measurements, but it's hard to have a nonchalant attitude of "this is just a silly game" when you're connected to devices that do in fact actually measure those things.
      - Canada 12y ago
        The presence of the machine changes the nature of the interview. It's like how being interviewed on the phone at home and being interviewed handcuffed to a table with a gun your head are different. It really doesn't matter much if the interviewer actually intends to shoot you or not. The mere presence of the prop induces stress making it difficult to think clearly and avoid being manipulated by the interviewer. To succeed in the situation your mind must be prepared to deal with the gun or the handcuffs or the polygraph. I doubt many people are able to simply ignore them.
  - doorhammer 12y ago
    For me it would be a matter of personal strategy. Basically, is standing on principle the most strategic thing I can do given my goals in the situation that left me on the receiving end of a polygraph? Even if my strategic goal is to show that a polygraph is meaningless, being able to pass or fail one at will could be really useful to that end. The odds seem pretty low that any job or clearance requiring a polygraph would let you get by without one, even if you displayed an extensive knowledge of them and how they're flawed. Personally, if acting on principle, I'd probably just not want to work at a place like that to begin with. Of course, I'm sure there are some highly sought after individuals that could get by with that, and it probably depends on whether or not the organization you're engaging with views the polygraph seriously or as a relic on its way out. If it were something to do with legal proceedings, I'd have to talk to a lawyer first, and see what was in my best interest. As far as term semantics go (which I think are important), maybe "manipulating" would be a better word than "beating" or "cheating" edit: The sibling poster also has a really good point about everyone possibly knowing it's a sham, but using it as a tool to get rid of people they want to get rid of. That might be more likely than all my speculation
    - tptacek 12y ago
      Ok so I think we may be talking past each other here. I'm not arguing about the legitimacy of polygraphs. They're hokum. I'm keying in on things like "being able to pass or fail [a polygraph]". "Able" to "pass" or "fail"? Would you say the same thing about being able to pass or fail a psychic palm reading? I feel like I'm missing something, which is why I keep asking.
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  - Cushman 12y ago
    > Is it that I'd have to account for the fact that they might irrationally believe in the machine, and adjust my performance to fit that irrational belief? Well, yeah, wouldn't you? I mean, the fact that you're being given a polygraph implies that your interrogator believes it has some effect that benefits them. And if you're completely convinced that that isn't true, meaning the human-with-polygraph is not more reliable than an unaided human, that still leaves the possibility that the human-with-polygraph is worse in a way that affects you. If there's a possibility for the device to convince your interrogator that you're being deceptive, but you're honest, you're taking a risk unless you attempt to avoid causing a false positive. Conversely, if there's a possibility for the device to convince your interrogator that you're being truthful, and you're deceitful, you're missing out on an advantage unless you attempt to cause a false negative. There's no case where your interrogator is better off, so your premise isn't invalidated; the polygraph itself is still bunk. But it's your interrogator's trust in it which has created a relative advantage for you if you play along. The exact same applies if they show up with a "psychic", although it might be harder -- or easier -- to manipulate.
moron4hire 12y ago
The problem is the operator is trying to unnerve you and embarrass you, specifically to fluster you. They don't just just ask you the questions they're interested in. They ask you about your personal sexual habits and other things designed to trigger an emotional response. It's all just a sham. The more honest of a person you are, the less likely you are to pass the polygraph on your first try. And the only way the polygraph works to catch out liars is to use the shame of the situation to coerce a confession out of the person. Say they ask you "have you engaged in homosexual behavior, especially under the age of 14?" Most people I know, given the situation, will blush. And blushing is basically all a polygraph can actually measure. So now they start berating you that you lied, and if you continue to insist you didn't lie about that particular question, they say it means you lied about a previous one. The only way to pass a polygraph is to know what they are like and just get through it. Honest people and liars both just need to stick to their stories, regardless of what the polygraph is saying, because eventually they will just fail you and schedule you for another one. Repeat until you've been through it so many times it doesn't phase you anymore. Then their job is done, their job being, "it wasn't my fault if you turn out to be a spy."
- tptacek 12y ago
  Sure! But there are lots of situations in which a counterparty in a discussion has an off-putting advantage (see: every job interview), and yet we don't generally offer advice to candidates along the lines of "tense and relax your anal sphincter repeatedly" or "visualize your happy place on target questions and your worst nightmare on control questions". Is where I'm going with this clear? I feel like I'm just confusing everyone with this line of questions. I'm literally just asking: If I was given a polygraph tomorrow, knowing what I know now (in fact having conviction about what I know about polygraphs), wouldn't a reasonable strategy be to ignore any polygraph-specific advice, and manage the process the same way I would if there was a Magic 8 Ball adjudicating it? I know there are differences between the plastic toy and the fortune-telling billiard-ball, but are they meaningful?
  - moron4hire 12y ago
    A magic 8 ball would be just as effective of a prop in the play that polygraph operators play.

justincormack 12y ago

The US is pretty much the only country that uses polygraphs with any frequency. In Europe [1] they are not used. The US needs to stop using the bogus devices. [1] http://en.wikipedia.org/wiki/Polygraph#Europe http://en.wikipedia.org/wiki/Polygraph#Europe

tptacek 12y ago
They're mostly discredited here as well. Criminal defendants can't be forced to take them. In virtually all states, defendants can suppress polygraph evidence. In some of the states where polygraph evidence is allowed (by consent of defendants), the defendants apparently also get a civil cause of action against the polygraph vendor. Unfortunately, we still use them as part of a hazing ritual to get clearance for national defense projects. But the poster upthread is probably right that those kinds of projects aren't the ones you want to be working on anyways.
- learc83 12y ago
  The interesting thing about polygraphs is that they can be an effective interrogation tool as long as the subject believes they work. (but then again so Santa Claus if the subject believes in him) For instance the interrogator says, "the polygraph says you're hiding something from me, are you sure there isn't something you want to get off your chest." The should however, be banned completely because the false positives are so high that we are crippling many of the agencies that rely on them. We're forcing them to drastically reduce their potential talent pool based on pseudo science.
  - rdtsc 12y ago
    > the false positives are so high that we are crippling many of the agencies that rely on them. Even worse than that, it selects for people who lie with impunity without any visible or emotionals qualms about it -- basically it selects for psychopaths.
    - sukilot 12y ago

jpmattia 12y ago

I would love to see polygraphs calibrated with a simple game of hi-lo. Pretty simple metric: Pick a number 1-1024, the questioner gets it right or wrong.

rquantz 12y ago

Given that the test is essentially measuring whether you respond to a question with an adrenaline burst, I wonder if taking beta blockers prior to testing can influence the results. That would be my first instinct.

troisx 12y ago
Some places test for drugs in your system along with the polygraph test since beta blockers are sometimes used to help beat the test.

zkhalique 12y ago

Well, this is the first thing I would think of, if I wanted to cheat on a polygraph test. Obviously I would just try to be more nervous at the control questions, to establish a baseline that wouldn't make the lies stand out. I'd imagine I'm lying on the control questions.

fnordfnordfnord 12y ago

The polygraph is quackery. They may as well just phone Miss Cleo and ask her if someone is lying. But good on them for pointing out how they are still used to coerce people.

USNetizen 12y ago

These are often used as part of required policy for the US federal government in certain types of security clearances. They seem to be used more as a psychological influence on the person undergoing the clearance than actually working to detect their deception, so I agree with that point in the article. Case in point, Snowden would have most likely had to undergo at least one of these polygraph tests for the cleared work he did and that didn't exactly prevent anything. Plus, people that are pathological liars can essentially convince themselves that something is the truth which these tests would rarely, if ever, pick up on as deception.

a8da6b0c91d 12y ago
I think the tests do in fact "work" in two senses. First, tons of people with "compromised" histories unsuitable for cleared work freak out and fail or even outright confess things they were concealing. That there's no real lie detection going on is irrelevant. As an interrogation tactic it still functions to some extent. Secondly, a lot of nervous nellies fail, even though they're squeaky clean. For a lot of the work where the tests are used you really do want to exclude people who can't keep their cool under a bit of pressure. If you freak out under the kind of questioning done, you're probably going to freak out in a way that reveals information if somebody starts asking about your work.
- fnordfnordfnord 12y ago
  I disagree, and I think that polygraph tests filter out good people in favor of deceptive people and convincing liars. >For a lot of the work For a tiny fraction of the work. Maybe you underestimate the number of jobs that use this quackery.
  - a8da6b0c91d 12y ago
    > deceptive people and convincing liars. My point is that to some extent this is actually a necessary skill. You absolutely don't want people who can't keep cool and put out a bit of smokescreen and do some hand waving.

geomark 12y ago

I once had to take a polygraph to be considered for a security clearance. For various reason I didn't want it - I didn't want to join the group of social misfits I knew who worked on classified projects, I didn't want project security telling me where I could go on vacation and with whom I could associate (no foreigners), plus I had a few ethical objections. But at the time I liked my job (lots of great unclassified tech work), wanted to keep it, and needed to go along with my bosses' desires to get me cleared. The polygraph was administered by a strange guy from a three letter agency. I did the sphincter squeeze for every question. He said the test showed I was being deceptive. I thought that was the end of it and hoped my boss would leave me alone about it. But they called me back to do another one. This time I didn't do the sphincter squeeze. He said the test showed I was being deceptive. I don't know. I think the test just showed I didn't want to get a clearance.

moron4hire 12y ago
Polygraph operators are superstitious idiots, no better than TV psychics and climate-change deniers. They're a liability to the integrity of our security services, because they are physically incapable of performing a job that they certify has been performed.
BorisMelnik 12y ago
Many times they will make comments to get a reaction from you, such as: "Looks like you are telling the truth.." (even if it shows otherwise) If you look relieved or surprised, this might be something that they can use at a later date or further along in the interview. Polygraphs are 100% interpretation, they are not binary by any means.
- pakled_engineer 12y ago
  Exactly, it's just an interrogation prop like when the East German police would have the fake telephone where they pretended to make calls to family/friends and verify your story, and had a button under their desk to make the phone ring so they could pretend to get just in time information to refute your story. Modern police will go into an interrogation with a decoy file folder full of random papers and then go through it claiming the contents refute your entire story and you'd better confess too. A standard polygraph trick is to switch it off, and then have a casual interview during the middle of the test. Then they claim they never switched it off and you've been lying the whole time as your casual results differ on the magic box. Props tend to work to get people to trip up on their replies even if the prop is just a box that randomly scribbles on paper with absolutely zero scientific credibility.

logfromblammo 12y ago

The only way to win is not to play. If you are ever in a position where you have to take a polygraph test, you have already failed.

PhantomGremlin 12y ago
The only way to win is not to play This is often forgotten. In so many situations in life, people think they must make a choice being forced on them, "yes or no" or something similar. Quite often the best choice is not to not allow yourself to play that game. Instead, learn to "think outside the box".

late2part 12y ago

This is a great article! There's a reason that polygraph tests are not normally allowable as evidence in court!

S_A_P 12y ago

To get security clearance you need to go through government sponsored auditing. They don't want any thetans to get access to state secrets.

Liquix 12y ago

It does seem much more similar to psychological torture than actual conclusive detective work...

mellavora 12y ago
you say that like there's a difference :)

mml 12y ago

When I was a kid, the polygrapher for the local maximum security prison was a member of the family church. He came in to school one day and did a demo for the kids. One memorable thing he said was that during an examination, there is only one lie detector in the room, and it isn't the machine.

sukilot 12y ago
And there is at least one liar in the room, but it isn't always the interrogatee.

snarfy 12y ago

One of my high school students who was an ex detective taught my class how to beat them. He said put a thumb tack in your shoe, and when asked each question, step on the tack slightly, enough to cause pain. A lie registers as a blip, but so does pain. If every question has a blip, they cannot differentiate.

kelseyfrancis 12y ago
> He said put a thumb tack in your shoe The examiner can just require subjects to remove their shoes.
blumkvist 12y ago
> One of my high school students who was an ex detective I read this many times. Can you expand on how a detective ended up as a highschool student? Sounds like a fun story.
- snarfy 12y ago
  > One of my high school students who was an ex detective Should be "One of my high school teachers..."

loteck 12y ago

Never been polygraphed but I always wondered about an alternative to the "emotional control" approach to beating it that is discussed in the article. My alternative would be to trick my mind into not lying despite the question asked. So if I was asked "do you live in Chicago?" (i don't) and I wanted to answer yes, I would simply internally ask myself "is your name loteck?" and then respond "yes." I would ignore the actual question asked by the interviewer except to the extent I need to pick which internal question I would ask myself, of which I would only have 2. One for yes responses and one for no. Anybody have any idea if this would work?

PavleMiha 12y ago
I'm definitely not an expert in the area (never even taken a polygraph), but I highly doubt you could prevent yourself from getting nervous/agitated when asked a question about something you had to lie about. Don't think most people are that good at controlling their emotions, even if the question in your head is different you still know what the intimidating investigator actually wants to know.
superuser2 12y ago
Lying on control questions is not advisable. A polygraph would be conducted inside of a larger investigation which would, among other things, fact-check your claims by other means. These data would be considered in the interpretation of your polygraph results. Whether or not you live in Chicago is very easy to check; when they see that you are lying on control questions they will consider everything else suspect. In the contexts in which polygraphs are applied (i.e. security clearance, witch hunts within security services), simply being suspicious in this way is enough to cause the negative outcome (i.e. not getting the clearance, getting fired), so even if it might muddy the evaluation of your response to, i.e. "Are you a Russian spy?" it would still cause the negative outcome. It has no bearing on criminal prosecution, because polygraphs are already inadmissible.
- dean 12y ago
  If you lie on a question that is easily fact-checked, and the polygraph shows that you told the truth, doesn't that just prove that the polygraph doesn't work? To my mind that is a simple test that disproves the effectiveness of the tool. It should cause a reasonable person to conclude that the tool doesn't work and should not be used.

caycep 12y ago

this is another version of the "machine learning" prob isn't it? the machine collects a bunch of basic physiological variables and makes a prediction, you just have to figure out what those variables are, whether it's hr, bp, etc

mml 12y ago

The ol' tack in the shoe trick was specifically noted as bunk by the examiner I knew, and the sphincter clench is semi-widely known. What I would find difficult with each of these tricks, is that you have to execute them during control questions, and not during "real" questions. Keeping track of when to clench or not while simultaneously trying to keep reality, and one's deceptions straight seems like it would be extremely hard to do under even mild pressure.

kelseyfrancis 12y ago
Plus you'd probably have to remove your shoes and there'd probably be a force sensor under your butt.
sukilot 12y ago
Not to be too much of a truther, but a polygraph examiner has no interest in admitting that their work is bunk.
- mml 12y ago
  Perhaps he was a bit honest. These things happen sometimes.

jonathankoren 12y ago

I always thought George Castanza had the best polygraph beating strategy. "It's not a lie, if you believe it."

mhartl 12y ago
"Jerry, just remember: it's not a lie, if you believe it." https://www.youtube.com/watch?v=vn_PSJsl0LQ https://www.youtube.com/watch?v=vn_PSJsl0LQ

doorhammer 12y ago

If I recall correctly this book has an interesting section on polygraphs and a lot of other inaccurate methods and folklore around detecting lies and deceit: http://www.amazon.com/Detecting-Lies-Deceit-Pitfalls-Opportunities/dp/0470516259 http://www.amazon.com/Detecting-Lies-Deceit-Pitfalls-Opportu... It was really interesting when I read it, though it's a bit old now, so I'm not sure how much of the material needs to be updated.

faster 12y ago

When I was in high school I applied for a job in a VW performance shop a couple miles from my school. They sent me to the owner's neighbor for a polygraph, which surprised me but didn't seem like a big deal at the time. The guy was playing 'bad cop' from the second he answered the door, and said he was disappointed that I hadn't smoked pot on my way over because that makes reactions more visible on the polygraph. We went through his questions 3 times. The first time I just answered his questions, no games. The second time I tried to change my anxiety level sort of randomly (I had some experience with pretty high-end biofeedback equipment and knew how to affect the readings somewhat). The third time I used a breathing exercise that I was taught by a zen master to minimize my anxiety as much as possible. The polygraph operator was pissed, I decided that I had no desire to work for people who thought that was a good use of 45 minutes, and I didn't get the job. Everybody won, I guess.

DougWilliams 12y ago

It may be informative and entertaining to look at some of these videos on my website: http://www.polygraph.com/media http://www.polygraph.com/media And, if you are interested in more, read these essays: http://www.polygraph.com/index.php?i-don-t-teach-countermeasures http://www.polygraph.com/index.php?i-don-t-teach-countermeas... http://www.polygraph.com/index.php?the-lie-detector-is-bullshit-and-i-have-proved-it http://www.polygraph.com/index.php?the-lie-detector-is-bulls... And yes, I am the Doug Williams who is the subject of this article...

jakeogh 12y ago

Excellent resource on the pseudoscience of polygraphs: https://antipolygraph.org/ https://antipolygraph.org/

beedogs 12y ago

Polygraphs are about as useful and effective a tool as water-dowsing rods.

myhf 12y ago

There's an incorrectly joined infinitive in the second sentence.