[tingol]

You're wrong, they do not magically start working if you believe in them. If you're nervous for ANY reason it will give off a false positive. Not only if you're nervous of the machine itself.

It is insane it's still being used in the US.

[3pt14159]

In former CIA officer Valery Plame's book Fair Game, she describes how an old hand at CIA told her that the best way to get through the polygraph is to be as detailed and honest as possible. Even on subjects that would be embarrassing, merely focussing on describing the truth and knowing that the interviewers appreciate candor can often alleviate nervousness.

I've never been polygraphed and I have conflicting views on it, but I suspect if I were ever in the same situation I'd do the same thing. They may not work perfectly, but they are a forcing function to the interviewee. Are you going to tell the whole truth in all its messy detail or not?

That said, I don't think they belong in the justice system. Someone who is already accused of a crime has to choose between either doing a polygraph and being potentially being nervous because their freedom is at stake, or denying the polygraph and looking guilty.

[the_af]

If I remember correctly, note this is contrary to the advice the antipolygraph sites gives. They state anything the person interviewed admits, no matter how trivial, will be used against them (e.g. "have you ever smoked pot in college?"). That the "good cop" of the interrogation is always a ruse; and that since polygraphs don't actually work, small "admissions" are a big part of the actual information gathering... including the questions that are allegedly for "calibration".

[stefan_]

No, they don't belong anywhere. They are still useless.

[meroes]

One of Obama's staff, maybe press secretary said something similar. On NPR she said when they pressed about marijuana use in the screenings, she told them flatly she used it 500+ times.

But like you said, in a legal proceeding they are terrible to use.

[pc86]

Polygraphs are not used in US courts and the results are not admissible at trial, so I'm not sure what you're referring to in the last paragraph.

[mc32]

I think there is confusion/conflation with defendants offering to take a polygraph to prove innocence. Sometimes it’s a naive offer sometimes it’s someone who wants to “show proof” they “didn’t do it”.

[pc86]

Which is part of why they're inadmissible regardless of who wants to use them.

[mc32]

Sure but it’s usually a PR stunt by the defense “see my client is willing (therefore innocent as no liar would take the test the CIA uses to expose moles)”

“We took a privately administered test by a certified polygraph administrator and my client passed with flying colors!!!”

[firebaze]

> If you're nervous for ANY reason

Agree, and also agree, it's insane. Still that's the presumed thinking behind it.

The (anti-polygraph-myth) site I linked comes to a similar conclusion.

[unishark]

> You're wrong, they do not magically start working if you believe in them. If you're nervous for ANY reason it will give off a false positive. Not only if you're nervous of the machine itself.

If you're just as nervous during control questions as lies then it would be a false negative. The "tack in shoe" tactic is supposed to make yourself uncomfortable during control questions by stepping on the tack and raising the baseline.