Every 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.
To 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.
I 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.
I 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.
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... ); 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)
It's a fun idea, but even the premise points out the major fault: "whether someone thinks they are telling the truth".
Studies on memory show that human beings, as a whole, are terrible at remembering things. We edit, we re-write, we create. Almost certainly some event you remember clearly from more than 20 years ago either did not happen at all, happened to someone else and you heard about it, or happened in a completely different way than you remember. That's true for just about everyone[0].
What good is a device that can tell if you believe you're telling the truth when your beliefs and memories are so flaky anyways?
[0] Except my wife, whose near-eidetic memory is frightening.
They 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.
This 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:
Yes. 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.
It'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.
I 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.
Julia 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".
Maybe 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.").
I 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.
The 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?"
Polygraph 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.
"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."
It'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..
Through 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.
What 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).
Yeah 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
I 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?
Nothing 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
> I was surprised - and dismayed - that the polygraph was still being used
Keep in mind that it was being used here by Ford, not by the FBI or Congress. I think the people who mattered are well aware they don't really work, but is also aware of their potent PR value (thanks to years of bad Hollywood science and cliches police procedurals).
I suspected something fishy was up with that the moment Ford mentioned she'd taken a polygraph. Even if it's not commonly understood by the general population (and I'm fairly sure it is) Ford is a psychologist and the hearing was full of lawyers - I'd expect that milieu to be even more informed on the shortcomings of lie detectors than the general population.
What's shocking to me is that in investigations involving the use of polygraph someone(higher officials) were keen on getting desired results out of it, in hope to wrap up investigation the way they want.
[+] [-] jpmattia|7 years ago|reply
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|7 years ago|reply
[+] [-] module0000|7 years ago|reply
[+] [-] gnu8|7 years ago|reply
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.
[+] [-] sytelus|7 years ago|reply
[+] [-] mherdeg|7 years ago|reply
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... ); 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)
[+] [-] mabbo|7 years ago|reply
Studies on memory show that human beings, as a whole, are terrible at remembering things. We edit, we re-write, we create. Almost certainly some event you remember clearly from more than 20 years ago either did not happen at all, happened to someone else and you heard about it, or happened in a completely different way than you remember. That's true for just about everyone[0].
What good is a device that can tell if you believe you're telling the truth when your beliefs and memories are so flaky anyways?
[0] Except my wife, whose near-eidetic memory is frightening.
[+] [-] mikeash|7 years ago|reply
[+] [-] unknown|7 years ago|reply
[deleted]
[+] [-] jwally|7 years ago|reply
https://www.thisamericanlife.org/618/mr-lie-detector
[+] [-] ap_org|7 years ago|reply
For more on Doug Williams' case, see: https://antipolygraph.org/litigation.shtml#doug-williams
[+] [-] lbriner|7 years ago|reply
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.
[+] [-] kevinmchugh|7 years ago|reply
[+] [-] nyolfen|7 years ago|reply
[+] [-] gxigzigxigxi|7 years ago|reply
[+] [-] stedalus|7 years ago|reply
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.pd...
[+] [-] everdev|7 years ago|reply
[+] [-] air7|7 years ago|reply
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.
[+] [-] technofiend|7 years ago|reply
https://rationalwiki.org/wiki/Presupposition
[+] [-] ap_org|7 years ago|reply
[+] [-] aphextron|7 years ago|reply
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|7 years ago|reply
https://www.nytimes.com/2002/10/10/opinion/lying-lie-detecto...
[+] [-] unknown|7 years ago|reply
[deleted]
[+] [-] deisner|7 years ago|reply
[+] [-] ggm|7 years ago|reply
You could apply this logic to the gun control question too..
[+] [-] z3t4|7 years ago|reply
[+] [-] unknown|7 years ago|reply
[deleted]
[+] [-] IshKebab|7 years ago|reply
[+] [-] autoexec|7 years ago|reply
You can get some info here: http://noliemri.com/
[+] [-] dang|7 years ago|reply
[+] [-] thoughtexplorer|7 years ago|reply
I've long been under the impression that it was commonly understood that the polygraph was fallible. Has this changed?
[+] [-] ap_org|7 years ago|reply
[+] [-] __blockcipher__|7 years ago|reply
[+] [-] Diederich|7 years ago|reply
I am also dismayed, but not surprised.
[+] [-] Lazare|7 years ago|reply
Keep in mind that it was being used here by Ford, not by the FBI or Congress. I think the people who mattered are well aware they don't really work, but is also aware of their potent PR value (thanks to years of bad Hollywood science and cliches police procedurals).
[+] [-] SuoDuanDao|7 years ago|reply
[+] [-] astura|7 years ago|reply
Especially since they are required for some government jobs.
[+] [-] new12345|7 years ago|reply
[+] [-] rustcharm|7 years ago|reply