Is a polygraph 100 accurate

The physiological responses the test monitors, for example, are not unique to deception.But a polygraph is not perfect:19 states allow polygraphs to be admissible in the guilt phase of a trial only after stipulation between the defendant and prosecutors.If this view is correct, the lie detector might be better called a fear detector.Remember to tell the truth.

Even though polygraph testing is very reliable, there are sometimes errors, and some people are concerned that those being examined can use methods to beat the test.The polygraph has been around for almost 100 years.The belief underpinning the use of the polygraph is that deceptive answers will produce physiological responses that can be.The current polygraph research indicates that when a specific single issue polygraph exam, when conducted by a qualified, trained, and experienced polygraph examiner and is properly administered, the accuracy rate is between 90% and 92%.On the other hand, opponents say that the accuracy rate of a polygraph exam is little better than could be achieved by the toss of a coin (iacono and lykken, 1997).

For those who don't know, a polygraph test is a machine that records the body movements of a person while the instructor asks them a number of questions.That 40% of honest examinees appear deceptive provides exceedingly poor protection for innocent suspects, suggests lilienfeld (p.The truth is, dna, fingerprints or handwriting analysis are not 100%.