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European Researchers Develop More Accurate Full-Body Polygraph 106

Posted by Soulskill from the we-need-a-brain-biopsy-to-confirm-your-story dept.
jfruh writes: Despite their widespread use in industry and law enforcement, traditional lie-detector polygraphs give accurate results only about 60% of the time, barely better than the 55% accuracy people can get just by following their gut instincts. Now researchers in the UK and the Netherlands are trying to improve that. They claim a full-body polygraph based on motion-capture suits used for movie special effects can detect lies with 75% accuracy.
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European Researchers Develop More Accurate Full-Body Polygraph More

European Researchers Develop More Accurate Full-Body Polygraph

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  • Accuracy (Score:3)

    by Fire_Wraith ( 1460385 ) on Monday January 05, 2015 @08:34PM (#48742209)
    75% of the time, it works all of the time!

    • Re:Accuracy (Score:5, Insightful)

      by Dorianny ( 1847922 ) on Monday January 05, 2015 @08:41PM (#48742263) Journal
      polygraphs are as much a science as astrology.

      • Re:Accuracy (Score:5, Insightful)

        by Jumunquo ( 2988827 ) on Monday January 05, 2015 @09:02PM (#48742391)

        Exactly. There's no reliable body response for a lie. All they are measuring is nervousness, which you could have for a variety of reasons. It's the same thing the border agent does.

        The purpose of the polygraph is to bully the victim into a confession. The unknowing victim thinks they are undergoing a scientific test, but they are actually being drilled by a skilled interrogator w/ no lawyer present to defuse the loaded questions.

        • Re:Accuracy (Score:4, Informative)

          by s.petry ( 762400 ) on Monday January 05, 2015 @09:34PM (#48742583)

          Yup, the basics of the "classes" people give to beat a polygraph are summarized as relaxation techniques. (Oh noes, will I go to jail for revealing the "secret" that's all over the internet? Oh, I'm okay because I didn't charge for it.. *whew!*). Mask the nervousness and you can spin some wild tales while hooked up and look to be absolutely truthful. Don't get me wrong, it takes a bit of practice but has been proven to work repeatedly. Most often by former "experts" in polygraphs that want to prove what a sham they are.

          • Re: (Score:2)

            by AK Marc ( 707885 )
            Or, if you are a bad liar, be nervous for everything. When you "fail" all the true answers, the test will be rejected as "inconclusive" which isn't a pass, and isn't a fail.

            The smarter you are the harder it is to pass. The more sociopathic you are, the easier it is to pass. Why do smarter people fail?

            Did you eat pig last night? [thoughts] "Um, I ate a beef hotdog. I wonder if that had secret pork in it."[end thought] "no"
            The uncertainty in the thought process will trigger a nervous response, even

            • Well, that sort of illustrates why the test is wrong so often, but if you TRY to be bored and aggressive, you'll probably think too much ;)

              The way they teach you to beat it is pretty simple. Before they ask the hard questions, they need to calibrate. They will ask you something easy to get a base truth response. Likewise, they will get a base lie response. You want your base lie response to go sky high so that nothing can ever match that. Bite your tongue. Tighten you ass. Whatever you like. Once yo

              • Re: (Score:3)

                by AK Marc ( 707885 )
                And if you think too much, you'll "fail" every question. "fail" the baseline questions, like your name, and they give it to you a few times, then treat it like a pass. They have no other choice. Repeated "inconclusive" is a pass.

                They can still ask all sorts of loaded questions. For example, have you ever done something personal during work time?

                And they give you the questions ahead of time so you won't be confused/blindsided by them. Have you ever done something personal on work time? Yes. Everyone has. I peed today. Oh, and I stood around the water cooler and talked non-work things to my coworkers. I even took off

                • Re: (Score:2)

                  by gweihir ( 88907 )

                  As to movie store: They do not want employees that are good at it. If they wanted that, it would not be minimum wage. They want employees that do not cause problems.

                  • Re: (Score:2)

                    by AK Marc ( 707885 )
                    Especially now, there are enough applicants to minimum wage jobs that they can afford to be picky. If there were more jobs than people, the employers wouldn't care if an employee smoked a joint once a month outside work hours.

                    • Re: (Score:2)

                      by AK Marc ( 707885 )
                      It's more commonly called UBI (universal basic income).

                    • Re: (Score:2)

                      by AK Marc ( 707885 )
                      That's a UBI, it's just so low that nobody talkind about UBI would consider it UBI. I understand your plan 100%. It's UBI. I could achieve the same results with UBI and taxes.

                    • Re: (Score:2)

                      by AK Marc ( 707885 )
                      It provides a minimum income level to all people. That is what UBI is.

            • Re: Accuracy (Score:1)

              by Anonymous Coward

              It helps if you're naturally bore...ah fuck this noise, and your little dog too.

        • Exactly. There's no reliable body response for a lie. All they are measuring is nervousness, which you could have for a variety of reasons.

          A polygraph measures nervousness on one axis and time on the other.

          The point is not to measure if the subject is generally nervous, it is to measure a nervous reaction to stimulus, usually a question posed by an interrogator.

          Polygraph results are not admissible in court, they do not override a suspect's right to not answer questions and unlike torture there is no real evidence that they lead to false confessions. A stupid but innocent suspect could only believe that the polygraph will exonerate them. It's n

        • Re: (Score:1)

          by Anonymous Coward
          sure there is. when you clench your asshole, the polygraph detects a physical baseline change, AKA a "lie". lie detectors detect lies, therefore clenching your asshole is a reliable body response to a lie. QED
        • No so-called 'lie detector' can be calibrated for the situation where the person undergoing the test has, in the past, been repeatedly threatened with death if he tells the truth.
      • The difference is that we don't as a society (generally) rely on astrology for anything of serious consequence. With polygraph tests though, they're used to screen for employment in critical defense and intelligence functions, and in legal proceedings. Even though it's not compulsory, the gross inaccuracy should rule them out for any serious consideration even when someone agrees to take it. Even 75% means a 1 in 4 failure rate, and regardless of how many of those are false positives vs false negatives, tha

        • I found this to be a great read on the subject:
          https://antipolygraph.org/lie-... [antipolygraph.org]
          They actually talk about specific cases concerning the trouble use of this for defense and intelligence, and why it's such a sham. You also see that they probably keep using it even though it's inaccurate because it beats some confessions out of some people, and I guess they don't mind the innocents that get screwed by it.

        • large swathes of the population believe in Astrology.It is reported that even recent powerful world leaders Charles de Gaulle, Boris Yeltsin and Ronald Reagan consulted astrologers. While the exact impact of astrology on swaying opinion and ultimately influencing events can't really be quantized it is in my opinion certainly not trivial.

        • Even 75% means a 1 in 4 failure rate

          Ever been to Las Vegas? All those sparkling lights and tall buildings were paid for by winning 52% of the time.

          • Re: (Score:2)

            by gnoshi ( 314933 )

            Sure, but that was winning 52% of the time where each individual loss or win were essentially irrelevant to the casino.

        • False negative v. false positive is very relevant here. I don't know what the rates are for a polygraph, but if there are no false positives (i.e. if it says you are lying then you are definitely lying) that would be extremely valuable even if it only works 75% of the time. When combined with other measures especially. Now if it says you are lying when you aren't that is a different story. An employer or gov agency might still be OK if the false negative is extremely low, since at worst you might reject a s

    • Re: (Score:2)

      by u38cg ( 607297 )
      So much kneejerk in this thread. Here is the paper [cam.ac.uk] and blogpost [lightbluetouchpaper.org].

      Protip: this research is being done by some of the best people in inter-disciplinary security, so reading and understanding what they are saying is a good idea before you spout off about how whack polygraph testing is.

  • so it can still be trained for (Score:3, Informative)

    by Friar_MJK ( 814134 ) on Monday January 05, 2015 @08:36PM (#48742225)
    just add full body motion to the list of do's and don'ts when you're taking the test. ever notice how often joe biden scratches his nose when he's talking out of his ass? yea, that's called a tell. i remember hearing about an indiana guy that was arrested for training people to beat polygraphs.

    • Re: (Score:1)

      by Anonymous Coward

      That sounds like the kind of thing that happens in militarized dictatorships. Which backwards-ass country was this?

    • that guy was arrested for claiming he would help people lie to the FBI. if he had just stuck with claim "I can help you beat a polygraph exam", he would have been fine. Once he said something along the lines of "I can help you beat an FBI polygraph exam", that became illegal.

      • I can train you on how to beat a Tarot reading. After all, Tarot done by a skilled "operator" is about as accurate as one with a polygraph, but you can't get arrested or denied employment for it.

  • 75% Accuracy is touted on Slashdot (Score:5, Insightful)

    by Bob_Who ( 926234 ) on Monday January 05, 2015 @08:42PM (#48742267) Journal

    I have a dowsing rod with better accuracy. My coin flip is 50% accurate. But lets convince everyone here that our standards for the truth are low enough to buy a bunch of polygraph apparatus that is 75% accurate, because technology is just not good enough to get to the truth. The truth is, this is totally stupid.

  • Great news (Score:1)

    by Anonymous Coward

    Now we need to make it compulsory for all politicians to use these when discussing their political manifestos to get in power...

    • Now we need to make it compulsory for all politicians to use these when discussing their political manifestos to get in power...

      So, let me get this straight... it isn't bad enough most politicians are already sociopaths, you want to actually institute a formal litmus test that is inaccurate, but favors sociopaths?

    • Now we need to make it compulsory for all politicians to use these when discussing their political manifestos to get in power...

      I figured they used politicians to train the device what a lie looks like.

  • As if getting a polygraph isn't humiliating.. (Score:4, Insightful)

    by mpthompson ( 457482 ) on Monday January 05, 2015 @08:52PM (#48742319)

    ...and stressful enough already. Now they'll tell you to strip and get into a silly motion capture suit. Next up is sticking a probe up our anus to measure the contraction of the sphincter muscles. After all, it's for our own good. How else will our overlords prevent another Snowden fiasco?

    • Re: (Score:3)

      by wbr1 ( 2538558 )
      Think that's invasive, try a plethysmograph [wikipedia.org]. Required of sex offenders everywhere.
  • Stephen Hawking for all the things he did!

    • Re: (Score:1)

      by Anonymous Coward

      You sir made my day :)

      For those of you who did not read the original article here is the relevant part:

      ... the sum of joint displacements was indicative of lying approximately 75 percent of the time.

    • surely they can match the tire marks his wheelchair left across my back...

  • If the makers are claiming 75% and nobody is trained against these kinds of polygraphs, they probably won't be a bit different in the real world any further than 5 years from now.

    • No, this one doesn't require tacks in the shoe and such stress inducements to beat it, you only have to practice good posture. So after a few years it might very well drop below 50/50.

  • MRI (Score:3)

    by manu0601 ( 2221348 ) on Monday January 05, 2015 @09:17PM (#48742481)
    I wonder why they don't use MRI or some other brain activity visualization technique; Recalling memory and forging a new story must be more distinguishable there than on body movements.

    • Re: (Score:2)

      by AK Marc ( 707885 )
      Variability between people and expense. And they can still be beaten, just as the EEG (or other brain scan) is beaten.

    • I wonder why they don't use MRI or some other brain activity visualization technique; Recalling memory and forging a new story must be more distinguishable there than on body movements.

      Different than recalling your cover story?

    • Re: (Score:2)

      by AmiMoJo ( 196126 ) *

      If you plan the lie in advance it becomes a memory.

  • Brain fingerprinting seems to be quit a bit better at detecting whether a person has knowledge of a crime.

    http://en.wikipedia.org/wiki/B... [wikipedia.org]

  • Instead broadening the area of interest, why not focus on where lies are actually formed, i.e. the brain? Put more effort in understanding the brain and on finding a way to detect changes to the brain when someone lies.

    • Re: (Score:3)

      by fnj ( 64210 )

      I know what would be even better. Let's use mutant precogs to find people guilty of precrime. Apologies to Philip K. Dick.

  • There are so many different types of lies, and so many different liars, I need some kind of control group to have confidence they don't just catch the ones who wet their pants (the 55% test). The worst ones I encounter are so goddam sure of themselves within minutes that I believe they could pass any garment.
  • "Despite their widespread use in industry and law enforcement, traditional lie-detector polygraphs give accurate results only about 60% of the time"

    There is no verifiable scientific evidence that polygraphs actually work.
    • I would also like to know if there is really a "widespread use" of polygraphs. I understood they were almost exclusively used in the US, and that most other countries actually forbade its use as evidence in courts - which would make the use of polygraph a local idiosyncracy rather than a widespread practice.

      • Re:Accuracy of traditional lie-detector polygraphs (Score:4, Informative)

        by Carewolf ( 581105 ) on Tuesday January 06, 2015 @06:39AM (#48744233) Homepage

        I would also like to know if there is really a "widespread use" of polygraphs. I understood they were almost exclusively used in the US, and that most other countries actually forbade its use as evidence in courts - which would make the use of polygraph a local idiosyncracy rather than a widespread practice.

        I think even in the US they are not allowed as evidence. They are used as interogation, but yes, I have never heard of any use outside of the US, at least they fell out of favor around the same time as phrenology.

  • Pseudoscientific nonsense (Score:3)

    by Required Snark ( 1702878 ) on Monday January 05, 2015 @10:42PM (#48742889)
    Yes, fitting a random person into a full body rig will have zero impact on the false positive/false negative rates. No problem.

    They tested this on 75 volunteers. This is an example of the kind of bogus "proof" that is used to justify the utility of polygraphs in the first place.

    It's in the same territory as drug companies excluding tests that show problems with their drugs. I'm sure if they ran enough small groups that they could find one with better then 90% and report only that.

    Why do polygraph advocates lie so much?

    • If you pay people to lie, they will.

    • Why do polygraph advocates lie so much?

      Because they use it as a tool to give an air of scientific legitimacy to otherwise shaky accusations. The truth often isn't their first priority, to say the least.

    • Re: (Score:2)

      by u38cg ( 607297 )
      (1) This is not a polygraph. It is an alternate technique with a similar aim. (2) It is an initial study whose purpose is to show there is an effect worth investigating. (3) You clearly have no idea who the people involved actually are. Hint: Ross Anderson knows a lot more about snake oil than you do.

    • Why do polygraph advocates lie so much?

      Because they know we can't prove they're lying?

  • Voodoo/2.0 (Score:3)

    by J'raxis ( 248192 ) on Monday January 05, 2015 @11:47PM (#48743155) Homepage

    In other news, the same research group has improved the accuracy of entrail reading by including other internal organs, doubled the accuracy of palm reading by using both hands, and are now hard at work devising ever-larger crystal balls in the hopes of refining their accuracy beyond "total bullshit."

  • polygraph=bullshit (Score:3)

    by ihtoit ( 3393327 ) on Tuesday January 06, 2015 @01:05AM (#48743467)

    File it with "Scientology bunkum".

  • Ob (Score:3)

    by Hognoxious ( 631665 ) on Tuesday January 06, 2015 @01:57AM (#48743629) Homepage Journal

    They claim a full-body polygraph based on motion-capture suits used for movie special effects can detect lies with 75% accuracy.

    I don't believe them.

  • Ironically, the claim that it is possible to detect lies has always been a con. Polygraph detectors are made by con artists.

    They can detect nervousness, nothing more. And of course if you lie to people that you can detect lies, that will make it a self fulfilling prophesy to the less intelligent.

    Of course a normal level of neurosis and intelligence will make you nervous when they as you an incriminating question. But since when did authorities care what happens to intelligent people rather than to gullib

  • This device is still flawed: it measure nervousness, which means that any psychopath will pass the test without any problem. It also means that people who get emotional easily will fail even if they tell the truth.

    IOW: garbage.

  • The blind earth bender Toph is the best lie detector on record. She detects the tiniest of the vibrations on earth and uses it to detect lies, even though she is totally blind. Her earth bending skills are so good she can fight many fire and water benders without even seeing them. But, despite all that, despite becoming the earth bending guru to Aang, she was fooled by the Fire nation circus performers. Shows there is no way to reliably detect a lie.
  • Comment removed based on user account deletion

  • All you really need to know is the claim that it "can detect lies with 75% accuracy."

    Nope; sorry, that's just *not* what polygraphs do; conflating "is stressed" or "showing a marked difference in measured body responses" with "is lying" is exactly the problem, no matter how accurate are the sensors.

    Everyone should read (it's free!) The Lie Behind the Lie Detector. Subtract agenda as necessary, but don't ignore the meat of it: https://antipolygraph.org/lie-... [antipolygraph.org]

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