Polygraph tests?

Question

Another puzzled Brit question! Why are polygraph tests carried out in the US if they are not admissible in court? (They are not done here in the UK to my knowledge.) Why bother doing them at all?

Answer 1

A polygraph is used strictly as an investigative tool. It isn't used in court because it has been known to be unreliable and naturally it isn't a tool to determine guilt. What it does do is alert the operator that something is amiss.
As you know, a polygrap reads changes in breathing, blood pressure and heart rate. The examiner will ask you a short series of questions unrelated to what you're going to be interviewed in regards to. This is a sort of "standard" for him or her to use. A couple of questions will be tossed in that are designed for you to lie. Then he/she watches the reaction of the chart. Now when you're questioned in regards to whatever the subject under investigation may be, he/she will see the needles jump if a lie is told.
Actually, the term is "Subject displayed deception on question #8). It gives the examiner or the investigators a route to start concentrating on and a way to discredit your alibi or pick apart your answers to get to what they belive will be the truth.

Answer 2

Polygraphs tests are useful in determining facts that can contribute to know the truth because a person could be determined if he is telling the truth when undergoing questioning. Although not admissible in court, polygraph tests determine the credibility of a suspect if making truthful statements.

Answer 3

The only time I've ever taken one was before they banned them from employment applications. I deliberately lied to see if it worked and easily faked lying. Other employees reported lying and never being questioned about it (one had been fired for stealing, never a bip.) One employee was accused of lying repeatedly, he was the one who told the truth about everything.

Why? A lot of people are bad at math, convinced the Polygraph givers are telling the truth when they claim 4% error rates (detractors say it is 70%), or just use them to detect nervousness, which they claim allows them to rule out suspects. It also looks good in the press, if you can claim to have taken one proving your innocence.

It's like a lot of pseudo-science. If it seems like a cool enough theory people will buy into it. Fox News seems obsessed with hand-writing analysis for personality traits, as if that is some how any more scientific than astrology. A few years back hypnosis for repressed memories was all the rage till that was proven to be bunk. There is yet to be a laboratory proof of psychic powers, yet millions believe psychics are finding criminals all the time.

Answer 4

Although they aren't admissible in court, they serve as a guide to determine whether or not a person is being truthful.

There is no sure-fire method to say if someone is lying or not. Moreover, a polyograph doesn't tell if your lying, it measurs your heart-rate and other biological factors in response to questions.

Answer 5

because the DA can except the results if it shows unsure or it say's your not telling the truth and child protective services can use the test results here to take your children away even though the test are not acurate. so they can adopt the kids out and make more money. they get a comishion on every child that the adopt out just like selling used cars.