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The Lie Behind the Lie Detector
- jwally 8y agoThis American Life did an episode about a guy who was a polygraph operator; discovered how flawed it was; and has been crusading against them ever since and teaching people how to beat them. Worth an hour of your day: https://www.thisamericanlife.org/618/mr-lie-detector https://www.thisamericanlife.org/618/mr-lie-detector
- ap_org 8y agoYes. That's the story of our friend, Doug Williams, who was targeted for entrapment by federal agents in a criminal investigation that targeted polygraph countermeasure instructors. We briefly discuss his case in the section on "Operation Lie Busters" in Chapter 4 of The Lie Behind the Lie Detector. For more on Doug Williams' case, see: https://antipolygraph.org/litigation.shtml#doug-williams https://antipolygraph.org/litigation.shtml#doug-williams
- dang 8y agoDiscussed in 2013: https://news.ycombinator.com/item?id=6307479 https://news.ycombinator.com/item?id=6307479
- lbriner 8y agoIt's scary that something that is not only controversial but also has laws (e.g. EPPA) in the USA that prohibits its use in some areas (displaying the lack of faith that the nation has on it), is not completely banned. If it is not generally used anywhere outside of the USA then it is way too fragile to be allowed anywhere. The principles are easy to understand but also easy to falsify as many people have, no doubt, found out to their detriment.
- nyolfen 8y agoit’s just an interrogation tool. everything about it makes more sense holding that in mind.
- kevinmchugh 8y agoSimilarly, SCOTUS upheld the use of drug-sniffing dogs a few years ago. The research seems to show that the dogs are effectively confirmation bias.
- tlrobinson 8y agoAt least we don't use dowsing rods: https://www.theregister.co.uk/2016/07/26/iraqi_government_finally_bans_debunked_dowsing_rods_for_explosives/ https://www.theregister.co.uk/2016/07/26/iraqi_government_fi...
- basementcat 8y agoMany people and organizations still do. In some parts of the USA, if you hire someone to dig a well on your property, they don’t dig until someone with a divining rod tells them where. https://www.theguardian.com/business/2017/nov/21/uk-water-firms-admit-using-divining-rods-to-find-leaks-and-pipes https://www.theguardian.com/business/2017/nov/21/uk-water-fi...
- deisner 8y agoI also enjoy this: "Why Lie Detectors Don't Detect Lies" https://www.youtube.com/watch?v=nyDMoGjKvNk https://www.youtube.com/watch?v=nyDMoGjKvNk -- 4.5 minutes long.
- mherdeg 8y agoYeah I treat it as "common knowledge" that polygraphs work about as well as the ADE 651 (https://www.nytimes.com/2009/11/04/world/middleeast/04sensors.html https://www.nytimes.com/2009/11/04/world/middleeast/04sensor...). It's always fun to think about how I could be totally wrong tho. Thought experiment: Suppose you had a piece of technology which could infallibly detect whether someone thinks they are telling the truth. To preserve the device's maximum efficacy, would you (a) keep it a secret and only use it for ultra-high-stakes investigations (as with cell-site simulators - e.g. https://arstechnica.com/tech-policy/2015/04/fbi-would-rather-prosecutors-drop-cases-than-disclose-stingray-details/ https://arstechnica.com/tech-policy/2015/04/fbi-would-rather... ); or (b) promulgate the idea that it is worthless or can be trivially manipulated to return any result, and train people to use it for everything? Hard for me to distinguish between a world where the polygraph does nothing and everyone knows it; and a world where the polygraph does nothing and everyone knows it (but that's just what they want you to think)
- mikeash 8y agoThey can’t subvert everybody. In the latter world, you’d have some independent researchers saying it was highly accurate. In reality, the ineffectiveness of lie detectors doesn’t seem to be in any dispute when studied scientifically.
- SmellyGeekBoy 8y agoThey're all in on the hoax! Just like those pesky evolutionists and climate scientists!
- penetrator009 8y agoI agree!
- dang 8y agoPlease don't do this here.
- mabbo 8y ago
- gxigzigxigxi 8y agoI wonder if a machine-learning approach really would learn how to detect lies. There is already a huge corpus to train on: police interrogation videos. It would take significant effort to label deception that was later confirmed. But I’ll bet we could teach a computer to see through almost any lie if we decided it was an important thing to spend time on.
- everdev 8y agoMaybe if you're looking at non-syntax indicators like pace of speech, posture adjustments, facial expressions, etc. But NLP is still a major unsolved problem. AI simply isn't strong enough at understanding meaning especially in broken English or slang (ex. "Nah, I ain't done it.").
- gxigzigxigxi 8y agoI’m not suggesting that the model would infer the truth from the input. Just that it would render a reasonably reliable estimate that the subject is dissembling. I don’t think the actual words used would be the principle component of such a determination.
- stedalus 8y agoJulia Hirschberg gave a keynote at this year's EMNLP on this topic. Short answer was that ML can do better than trained humans in some cases, but very far from "almost any". I don't think EMNLP has posted talk videos yet but these slides look very similar: http://www.cs.columbia.edu/~julia/talks/ICASSP2018-latest.pdf http://www.cs.columbia.edu/~julia/talks/ICASSP2018-latest.pd...
- air7 8y agoI remember reading somewhere an idea to make the polygraph produce more objective results: Instead of asking for example "Did you rob the bank?" and interpret the response as "lying" or "not lying" they can be asked "Was the getaway car white?" "Was the getaway car red?" "Was the getaway car blue?". By asking several of these you can statistically prove the suspect is guilty if they responded differently to several detail questions about information only they knew. Tthis doesn't help prove innocence (because people can beat the machine) but it reduces false positives and can therefor prove guilt (because it's unlikely a nervous person would randomly be more nervous when the true details are being asked vs. the decoys). Of course to be done right the operator must be "blind" (not know the answers and subconsciously tip the suspect off) and other statistical safe-guards need to be in place, so how useful in the real-world this is I don't know.
- ap_org 8y agoThe technique you're thinking of is called the Guilty Knowledge Test, which is seldom used. It's discussed at p. 121 of The Lie Behind the Lie Detector: https://antipolygraph.org/lie-behind-the-lie-detector.pdf#page=121 https://antipolygraph.org/lie-behind-the-lie-detector.pdf#pa...
- technofiend 8y agoThe rational wiki calls it a presupposition and mentions what I remember from logic class which is to respond "moo" although I could swear it was spelled "mu" when I learned the term. The example I heard was something like "So tell the court: have you stopped beating your wife?" https://rationalwiki.org/wiki/Presupposition https://rationalwiki.org/wiki/Presupposition
- tsuraan 8y agoI think the correct spelling is "無", but wikipedia lists english spellings as "mu" (from Japanese) or "wu" (from Chinese)[0] 0 - https://en.wikipedia.org/wiki/Mu_(negative) https://en.wikipedia.org/wiki/Mu_(negative)
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- thoughtexplorer 8y agoI was surprised - and dismayed - that the polygraph was still being used and given credence with something as high profile as the Ford/Kavanaugh hearing. I've long been under the impression that it was commonly understood that the polygraph was fallible. Has this changed?
- __blockcipher__ 8y agoNothing changed, but I’d estimate >50% of Americans still believe in “lie detectors”. They provide easy points when you don’t have actual evidence to bring forward
- lwansbrough 8y agoOver half of Americans believe cloud computing is affected by weather patterns [1]. So ya, I'm sure at least those same people believe in lie detectors. [1] https://www.businessinsider.com/people-think-stormy-weather-affects-cloud-computing-2012-8 https://www.businessinsider.com/people-think-stormy-weather-...
- applecrazy 8y agoSide note: the study you cite had the question as "is cloud computing affected by weather patterns?" This finding leads one to believe that nobody actually knows what the cloud actually is, but that is a bit sensationalist: technically data centers can be down due to weather-related power outages.
- derefr 8y agoA charitable reading: if you're aware that "cloud computing involves computers all over the world", but aren't aware that undersea cables carry 99.99% of international Internet traffic, then you might assume that cloud computing involves bouncing your Internet signal off a satellite at some point. Weather can interfere with satellite signals. Same goes for cell service: a lot of people tend to believe that, while your phone just talks to a cell tower, the cell tower is talking to a satellite (rather than to wired backhaul or a microwave link.) A satellite is depicted in all those diagrams of "how cellular networking works", so I don't blame them for this at all!
- module0000 8y agoI have taken and "passed" multiple polygraph examinations by US state-level agencies. Providing truthful answers would have disqualified me in each test, and I have never been disqualified. This book is very accurate, and has been my only influence/guide/assistance in every polygraph I have submitted to(ie I have no "training" in this field). I have not read this new edition, but I can't say enough good things about the prior ones.
- gnu8 8y agoI can’t see how it would be in your interest to post this. Are you not concerned that this comment could be tied back to your working identity and used against you? Another possibility is that you are a lying fed stirring the pot. For instance, a fed could point to your comment as evidence that antipolygraph.org is inciting people to break the law, which is a gambit they have used before.
- module0000 8y agoRead my comment again please - I'm not a lying fed, a troll, or anything else malicious. I'm not in the industry I once was, which involved regular polygraph examinations. I have no plans to return to the industry. Posting my comment carries zero-to-low risk for me. If it helps even 1 person, then it's worth it. All I'm saying is... if you are about to take a polygraph, or think you will in the near future: it is in your best interest to read this guide. On another note, after you read the guide and possibly benefit from it...you might find your attitude towards them changed. If the polygraph remains the de facto "lie detector", then we can all rest easy: because they are trivial to pass.
- mikeash 8y agoWhy would I rest easy if they’re trivial to pass? That’s great if I ever have to take one, but it really sucks if, say, someone passes one while falsely accusing me of a crime.
- module0000 8y ago
- jpmattia 8y agoEvery lie detector should begin with a game of high-low: The subject writes down a number between 1 and a 1000 and puts it in their shoe, the questioner needs to get the right answer. Since the questioner needs only 10 questions to get the right answer (+ control questions), it provides a practical calibration of whether the test is worth a damn or not. Prediction: No one will ever use my practical calibration of whether the test is worth a damn or not, until lie-detector technology is actually worth a damn.
- CobrastanJorji 8y agoTo play devil's advocate, a lie detector isn't really supposed to measure meaningless lies. It's about emotion and nervousness and the like. Math questions about a randomly assigned number would likely not generate much of a meaningful signal, and thus this test would not be expected to work.
- testvox 8y agoThen just make it meaningful by threatening to shoot the interviewee in the head if they fail to trick you.
- SuoDuanDao 8y agoYou could always offer the subject a hundred bucks (or some other significant amount) if he is able to obfuscate it.
- jpmattia 8y ago
- IshKebab 8y agoWhat about the "lie detector" they had on the recent update to Making a Murderer? I assume it is also bullshit (and the lawyer who used it seemed to think that too).
- autoexec 8y agoYeah it seems there are few new ideas for using brain imaging. I haven't looked into it too much yet, but I strongly suspect they are also garbage intended to trick people now that a fair number of us are aware of the polygraph scam You can get some info here: http://noliemri.com/ http://noliemri.com/
- aax888 8y agoLet's be real though. With brain imaging, we will eventually be able to accurately detect lies. This is one of many ethically charged issues where dismissing it as unreliable/pseudoscience will only work for so long before one that actually works is built.
- autoexec 8y agoI'm not convinced this will ever be the case. Even if we were able to somehow discover a part of the brain that only ever activates when lying what happens when someone says something truthful while also thinking of a lie? What happens when someone technically tells the truth but omits critical information?
- dragonwriter 8y ago> With brain imaging, we will eventually be able to accurately detect lies. That assumes that just because we have a distinct word for “lie” that that word has a clean direct correspondence with a detectable biological process.
- z3t4 8y agoThrough evolution we have become very good liars. Don't count on your natural ability to lie though, it's better to just shut up. While lies are next to impossible to detect, they are easily checked with facts.
- ggm 8y agoIt's never a good idea to base your feelings about jurisdictional specific things on this, but the fact that few other modern western economies think they're worth it bears thinking about: in so much else, law nowadays relies on everyone else's law to help define how to make it work. So, a new case in the USA can and will be cited everywhere else as a pertinant example of good modern law. But.. not in respect of polygraph evidence. Nobody else seems to want to include it as a routine praxis. Doesn't this worry American students of the law? You could apply this logic to the gun control question too..
- deleted 8y ago[deleted]
- aphextron 8y agoPolygraph testing has nothing to do with the scientific legitimacy of the actual instrument used. It's just an interrogation technique. Using it effectively is all about the skill of the person administering the test, and their ability to judge the person being tested. It is just one part of building a profile of whether you think someone is lying or not. The purpose of the test is to put someone through a highly stressful situation and see how they react to questioning. It's about determining whether they've been coached, and how familiar they are with details of the case, not determining a definitive "yes/no" response to specific questions. Polygraph questions can be passed with 100% accuracy by someone with extensive training, so it's entirely about building a gut feeling in the person administering the test as to whether you are lying or not.
- cafard 8y ago"Casey, just appointed C.I.A. chief, told me he was going to challenge Baker to a polygraph test to show who was lying. Figuring my old pal Casey was the culprit, I wondered why he would take the gamble. He reminded me he was an old O.S.S. spymaster, and that by using dodges like a sphincter-muscle trick and a Valium pill, he could defeat any polygraph operator. Baker wisely did not take Casey up on the challenge." https://www.nytimes.com/2002/10/10/opinion/lying-lie-detectors.html https://www.nytimes.com/2002/10/10/opinion/lying-lie-detecto...