Lie detectors

[murmur]

Or, how often are folk faked out by their own fears of a lie detector?

[cvb]

This just in from a UK-based senior psychologist friend:

... the lie detector program was approved and developed by well-informed psychologists including some of my colleagues. It's a bogus pipeline - they are using the lie detector to get more truthful self-reports (The Wire, S5E1). Of course they cannot widely publicise this, so it looks like they are using pseudoscience.

... the bogus pipeline is where people are more truthful when they *think* they are hooked up to an effective lie detector so that is what this UK "lie detector" programme is about but they can't let it be widely known that the lie detector is no more effective per se than the wired-up photocopier the police use to extract a confession in that episode of the wire

... they are not trying to fool other professionals, just the people subjected to the tests

So it will work fabulously well until the prison grapevine or the jihadi video networks tell people "BTW it's all fake, just don't crack and confess because you're impressed by the scary machine".

I was wondering about that but did not want to mention it in case I looked stupid.

[Pucksoppet]

This just in from a UK-based senior psychologist friend:

... the lie detector program was approved and developed by well-informed psychologists including some of my colleagues. It's a bogus pipeline - they are using the lie detector to get more truthful self-reports (The Wire, S5E1). Of course they cannot widely publicise this, so it looks like they are using pseudoscience.

... the bogus pipeline is where people are more truthful when they *think* they are hooked up to an effective lie detector so that is what this UK "lie detector" programme is about but they can't let it be widely known that the lie detector is no more effective per se than the wired-up photocopier the police use to extract a confession in that episode of the wire

... they are not trying to fool other professionals, just the people subjected to the tests

So it will work fabulously well until the prison grapevine or the jihadi video networks tell people "BTW it's all fake, just don't crack and confess because you're impressed by the scary machine".

I was wondering about that but did not want to mention it in case I looked stupid.

Well, given that the placebo effect works, even when you know of the existence of the placebo effect, it is not impossible that the same sort of thing goes on here. Allowing people the possibility of believing that lie-detectors/polygraphs work might mean that they are more likely to tell the truth. Or something handwavy like that. I am reminded of the mental processes in play when, in The Princess Bride Vizzini is trying to determine which goblet of wine he believes Westley has poisoned with iocane.

[cvb]

If you believe the person is more likely to be honest because they believe the lie detector works are you not more likely to believe their answers when they do lie?

The ones de-radicalised and telling the truth anyway are not the ones you want to catch.

[lpm]

Wait, on Jeremy Kyle they are hooked up to detectors, fervently believe in them and still lie like crazy.

[plodder]

Wait, on Jeremy Kyle they are hooked up to detectors, fervently believe in them and still lie like crazy.

That's because they get really muddled by all the permutations and game theory.

[Little waster]

Wait, on Jeremy Kyle they are hooked up to detectors, fervently believe in them and still lie like crazy.

That's because they get really muddled by all the permutations and game theory.

But only the ones with blue eyes.

[KAJ]

The Truth About Lie Detectors (aka Polygraph Tests) from American Psychological Association

[noggins]

If an accurate lie detector was technically possible, how would you actually know you had built one?

How would you do controlled experiments - how would you find a representative bunch of liars with serious lies to tell that you also knew were false?

[GeenDienst]

PMQs.

[Imrael]

Ask the other criminal what his friend would say?

[Sciolus]

To the extent that lie detectors operate as fear detectors, intimidating confessions out of nervous people, there must be a very real risk of generating false confessions out of innocent but suggestible people, in exactly the same way (if less extremely) that torture does. It is already known that confessions alone are not always good evidence of guilt. When asking not about a past crime but about intention to commit future crime, this seems a very likely outcome with some subjects.

[plodder]

A new, exiting lie detector is being used to fire people

https://www.theguardian.com/sport/2021/ ... ogy-boxing

[jaap]

A new, exiting lie detector is being used to fire people

https://www.theguardian.com/sport/2021/ ... ogy-boxing

It sounds like voice stress analysis which is hardly new, and surely still as bogus as it always was. Language Log has had many posts against it for the last almost 20 years.

[individualmember]

They’ve cropped up in a couple of tv documentaries that I’ve worked on, my opinion from researching them in that context is they are utter b.llsh.t. Pseudoscience if you prefer. Never anything more than a device used for intimidation.