Ex Member wrote on Feb 2^nd, 2017 at 1:50pm:

 
This is the best analogy I've ever read pertaining to the polygraph and its abuse.  The frauds that profit from the polygraph don't even try to "remove the unwanted particles " because no one holds them accountable for proven failure of their scam.  The only thing more despicable than the polygraph community are the executive branch officials and congressmen who allow them to flourish.

George W. Maschke wrote on Feb 2^nd, 2017 at 8:17am:

Lying is more cognitively demanding than telling the truth. This, in most people, will generate some set of physiological reactions just as mental countermeasures do. But a slab of marble also contains the David, the trick is to remove the unwanted particles.

George W. Maschke wrote on Feb 2^nd, 2017 at 8:17am:


The main value of the polygraph has little to do with measuring physiological changes, or indeed with any branch of science for that matter.  It is a tool for intimidation and instilling fear.

Much like astrology, the polygraph endures because popular perception places both in very high esteem.  In that regard, the polygraph advocates have indeed been most successful. 

Ex Member wrote on Feb 1^st, 2017 at 5:01pm:


The polygraph instrument is sensitive to fluctuations in breathing, perspiration, blood pressure, and heart rate, but there is considerable doubt about polygraphy's sensitivity as a lie test because the physiological indices measured by the polygraph haven't been shown to be systematically correlated with lying or truth-telling. As Dr. Alan P. Zelicoff put it, "From a medical and scientific standpoint, it is not sufficient to measure well that which should not be measured in the first place."

dc585 wrote on Feb 1^st, 2017 at 4:18pm:


Your words hit the mark precisely. There is little doubt about sensitivity, but specificity is the fly in the ointment.

Polygraph measure physical response from the body. It does not read the mind. I know for a fact that I can have huge physical response to a question and absolutely not be lying.
Could it detect a lie ? Yes, of course, but just because there was a physical response to a question does not always mean it was triggered by a lie. I would give it 50/50 at best, but it would really depend on the situation of course. More data to take into consideration than is.
Frightening stuff.

Quote:

  No, it's correct.  Use your brain.  Can measuring bio-reactions read someone's mind?  It scares me how many dim-witted people are running around today.  If they start burning witches again I think that half the population of this country would but into it.

dc585 wrote on Jan 27^th, 2017 at 3:23pm:


Probably for the same reason that its use is mandated by probation/parole authorities and required of registered sex offenders in  many states. 

Perhaps your information on reliability is incorrect

After realizing how inaccurate polygraph testing is, I am confused why in some states it is still Admissible in court?