4 ms·

In the UK we have a long running 'institution' called the Jeremy Kyle show. I believe it is solar to the Jerry Springer show in the US? Basically, low SES peopl

• rightbyte 7y ago
  "Lie detectors" are in practice a measurement of nervousity, right? "Oh, his heart rate jumped when I asked what the end score was in the game he said he saw in his home at the time of the murder even though he gave the correct score maybe he guessed."
  • ap_org 7y ago
    Polygraphs measure heart rate, breathing, and palmar sweating, which are affected by nervousness, but are not systematically correlated with lying. Voice stress analyzers don't actually measure stress in the voice.
    • 0815test 7y ago
      Even worse than that, there are in fact plenty of people who will systematically fail to show nervousness when lying, or more generally in socially-stressful situations, viz. psychopaths (in a broad sense, including Dark Triad traits more generally). As it happens, their lies are incredibly easy to detect for other reasons (basically, they never keep their stories straight, especially since they like to embellish them with all sorts of fanciful details), but still, it's hard to imagine a more catastrophic failure of this whole "lie detectors as infallible" paradigm.
  • rndgermandude 7y ago
    Not even nervousness per se. If you get angry, it will "measure" that too, as a lie. Or if you get embarrassed, that "measures" as a lie. My grandma would have failed any cheater polygraph test horribly, as she turned red every time anybody mentioned anything related to sex in general. You could have asked her if somebody she never heard of had extramarital sex, and her answer, no matter what she said, would have showed up as a lie every time. Physical or psychological exhaustion change the "results", too, of course. Or if you sit next to a window and the test takes long enough so that you start when you still sit in the shades but later the sun comes around and you sit in the light, that can be enough, too. Or if you deliberately clench your anal sphincter, that's enough to change results. And yes, that actually works; that's why some lie detectors now feature ass-clenching detention technology.
    • EForEndeavour 7y ago
      > that's why some lie detectors now feature ass-clenching detention technology This is one of the most entertaining sentences I've ever read on this website.
    • api 7y ago
      Sounds like psychopaths would do the best on these tests.
      • rndgermandude 7y ago
        Not necessarily, but it's certainly not unheard of: >In 2003, Gary Ridgway admitted he was the Green River Killer, having murdered 49 women in the Seattle area. Ridgway had passed a lie detector test in 1987, while another man - who turned out to be innocent - failed. https://www.bbc.com/news/magazine-22467640 https://www.bbc.com/news/magazine-22467640
  • aasasd 7y ago
    In one of Cory Doctorow's books, the trick to cheat a lie detector is said to be to clench and unclench the anus repeatedly for several minutes (in advance before the test). Purportedly, this agitates the nervous system so the measurements hike up, and on this background your legitimate discomposure will look like smooth sailing. The anus is probably chosen just for the inconspicuousness. Dunno how true this is and haven't heard of this trick elsewhere, though admittedly I haven't researched the topic. Other techniques in the ‘Little Brother’ books are real, apart from two or three that are doubtful to me.
    • aj7 7y ago
      Exactly, you use all sorts of ways to screw up the baseline.
    • Fjolsvith 7y ago
      In the US, they use a sensor pad the subject sits on to detect such attempts to modify the results.
      • EForEndeavour 7y ago
        I wonder if vividly picturing a cavalcade of ultraviolent mental images is enough to disrupt the test.
        • Fjolsvith 7y ago
          Unfortunately, disrupting the test is the same as failing it. Typically, subjects are expected to pass it to avoid negative consequences. I once went through a polygraph and used my meditative breathing techniques to calm my mind, and failed the test because I was "controlling my breath".
          • kevin_thibedeau 7y ago
            I mostly belly breathe and have little upper chest expansion at rest. This caused some consternation during my test.
  • spiraldancing 7y ago
    Lie detectors are a measure of heart rate, respiration, and galvanic skin response (roughly == how much you sweat). What relationship—if any—those have to the truthfulness of a person at any given moment, remains debatable at best.
    • sneak 7y ago
      There is no “debatable”: no correlation exists. Anyone who claims otherwise has to prove otherwise, and nobody has ever done so. No correlation exists.
      • spiraldancing 7y ago
        And yet we appear to be debating.
  • TazeTSchnitzel 7y ago
    This video with a former FBI agent about how they interpret body language was interesting to me: https://youtube.com/watch?v=4jwUXV4QaTw https://youtube.com/watch?v=4jwUXV4QaTw Lie detectors are basically like one of those body language tells. They don't tell you if someone is lying, but they can give you a hint as to how someone is feeling that might be useful in deciding what lines of questioning to pursue further.
  • derefr 7y ago
    The goal of the use of a polygraph in witness interrogation during criminal investigation (its original purpose, separate from all this bunk about “passing” or “failing” polygraph “tests”) isn’t to get the information the interrogation needs from the polygraph, but rather to use that information to steer the interrogation toward whatever seems to most upset the witness, because that’s usually something they’d rather not be talking about (and ergo something that may have involved them committing a crime, moving them from “witness” to “suspect.”) Of course, polygraphs don’t guide toward lies specifically, just toward uncomfortable subjects—which is why you hear about e.g. TSA screeners demanding to know if you were cheating on your wife, when that has nothing to do with things the TSA could care about. Whether or not they’re using a polygraph, the interrogation process involves digging for upsetting subjects; and so, if you have something upsetting you unrelated to the case at hand, they have to “dig it up” to “weed it out” of the interrogation, i.e. to put the way you’re reacting to questions about the subject they do care about in context. A witness who is very nervous because they’re off to visit their mistress, has had their nervousness “explained away”, and so being nervous is no longer suspect. (But other responses, like anger, still are leading. Being an interrogator requires recognizing differences in subtly-triggered emotions, because they usually have different sources. This is why so much was made of the power of “recognizing micro-expressions” back when, before that got mostly debunked.) And, of course, it’s pretty easy to train someone to control a polygraph signal, and some people are even naturally “immune” to being read by one. Mindfulness meditation works pretty well to defuse most of the physiological responses to stressful stimuli, for example, and interrogators have no idea whether you’re doing it. It works even better—if you’re a professional spy and have some time on your hands—to just sit around hooked up to a polygraph, watching its output yourself, as someone tries to upset you. (The polygraph is, in this case, acting as a https://en.m.wikipedia.org/wiki/Biofeedback https://en.m.wikipedia.org/wiki/Biofeedback mechanism.) Still, polygraphs were never intended to aid in the interrogation of professional spies; they were intended to be used like a drug-sniffing dog, to act as a quick heuristic to filter a large pool of “ordinary passers-by” (e.g. in a murder committed in a crowd) down to a few suspects who seem genuinely uncomfortable about something. Since most crimes aren’t committed by sociopaths, or Zen monks, or spies, but rather by people who think they have a momentary opportunity and usually regret their crime somewhat afterward, looking for discomfort tends to be fairly helpful in pre-filtering a large suspect pool; and using a machine that can detect “silent” discomfort is indeed an enhancement to that pre-filtering. (But, again, it’s only a pre filter. It’s a weak heuristic that needs following-up with further interrogation and detective work, to know whether to put these people on an actual suspects list. It’s common, when using such a heuristic, to filter some people in on the first pass, but filter every one of them back out in a second pass, and then realize you have to start from scratch with a different approach.) And, of course, there are going to be departments who know none of this, whose understanding of the use of a polygraph comes from cop movies, but who go out and buy one anyway, ditch the highly suggested training offered by the manufacturer (or don’t get access to it because they’re buying the device used), and then do stupid pass/fail polygraph “tests” where “passing” the “test” is exclusionary, as if you had a non-matching blood type to the suspect’s blood or something. (And there are also departments who just use a polygraph—real or fake—as a prop to perform “enhanced interrogation.” Interrogation doesn’t need “enhancement” IMHO—it doesn’t even need a stern voice—but at least interrogation with a polygraph-prop isn’t literally a crime and an abridgement of human rights in the way some other “enhancements” are.)
• maccard 7y ago
  > In all the media frenzy around the incident, I didn't see a single source mention that lie detectors are unproven bullshit. I've had the radio on for the last2-3 weeks and the BBC have been constantly saying that lie detectors are flawed and that the producers of the show apparently weren't even aware of this fact.
  • seibelj 7y ago
    I’m sure they were aware but admitting to that would have legal consequences.
  • walshemj 7y ago
    And Poygraphs are not used in security clearance in the UK as they are known to be bunk
• Mindwipe 7y ago
  It did come up explicitly in the DCMS subcommittee hearing on the incident, including headlines that the exec producer claimed he had no idea if they worked or not. I note that they haven't come up in Love Island yet this year as they normally do, and I suspect they won't.
• aj7 7y ago
  Yes, this is a very important issue.
• untruthGauge 7y ago
  In the United States, there has been at least one similarly deadly talk show episode, albeit without the lie detector tie in. https://en.wikipedia.org/wiki/Murder_of_Scott_Amedure https://en.wikipedia.org/wiki/Murder_of_Scott_Amedure In a way, you get the sense that these shows operate with the understanding that dead bodies are known to be a non-zero quantity, given the subject matter of taunting people on camera, such that they get their reputation thrown permanently into a relativistic black hole from which it will never escape. As for gullible people eating up lie detector results, as the saying goes, I don't have to outrun the bear... I only have to outrun you. Which is to say, it doesn't matter if you have firm grounds to disbelieve the lie detector test. I only have to convince your dimwitted peers, who are just itching for a reason to hang you. And as is evident, these TV shows prey on the slower people who simply need to see an interesting instrument and a convincing astrologer inspecting the dowsing rods. Here in the United States, there's a subtle hint that lie detectors are all but tea leaves: They are inadmissible as evidence in a legal context. As a rule of law, no judge will tolerate the results being used as proof of a fact. With a wink and a nod, this is how one is to clued into their actual value. But that's it. No one will accept the idea that they're worthless. They only point out legal inadmissibility as a point of trivia, and then move right along with whatever else they had to say.
• reaperducer 7y ago
  I don't understand how otherwise normal people believe we live in a world where reliable lie detectors exist Because for the better part of a century, the entertainment industry (and Hollywood in particular) has told us they work. They're a central plot device in tens of thousands of books, radio dramas, plays, television shows, and movies. It's like they say in politics: If you tell a lie enough times, it becomes the truth.
  • natechols 7y ago
    When I read this, I immediately thought of my favorite pop-culture lie detector reference: https://www.youtube.com/watch?v=ylthSc5tcqk https://www.youtube.com/watch?v=ylthSc5tcqk Still hilarious 23 (?) years later, but the laughs are based on the assumption that the device really works that well.