Why are all these well meaning individuals declining polygraphs?
"Lie detection" technology has a dodgy history and an obvious flaw that these folks can easily discover on the internet if they don't have a lawyer advising them. Only an innocent BM might consider taking a test, as a means of restoring his relationships and reputation. For anyone else, it could do more harm than good.
Although there are studies showing that - under carefully controlled conditions that rarely exist in actual criminal investigations - skilled polygraphers can accurately determine guilty and innocent subjects at rates that are better than chance, they cannot say whether a particular suspect who fails an examination falls in the the true positive or the false positive category.
Therefore, the accuracy rates in the studies may not be as impressive as they seem.
Let's say, a bank with 100 employees experiences losses over several months that are suspected to be the result of theft. Each employee is given a polygraph test, and the results indicate Joe and Jane stole the money. However, the real thieves prove to be Dan and Darlene. Even though the polygraph results were entirely wrong and misleading, the polygrapher can still claim an accuracy rate of 96% - all but four people were correctly classified.
Moreover, self-stimulating countermeasures (biting tongue, pressing toes to the floor, etc.) have been shown to reduce the polygraphers' detection of guilty suspects by 50% (Honts, Raskin, & Kirchner, 1994). And of course, some people are so controlled or nonreactive emotionally that lying produces little physiological response, while others overreact to some questions because of unique factors unrelated to their truthfulness.
Toward the end of his career, John A. Larson - a polygrapher who developed a widely used interrogation technique - became disillusioned with the widespread misuse of the polygraph. He complained that, "the lie detector, as used in many places, is nothing more than a psychological third degree aimed at extorting confessions as much as the old physical beatings were." (Skolnick, 1961, p. 703) This assessment was affirmed by the research of Richard Ofshe and Richard Leo, who published a study of false confessions in 1997.
New technologies have emerged that monitor modulations in the voice, dilation of the pupils, tension in the facial muscles, and neural activity in the brain. However, the enduring problem is that there is no distinctive set of physiological responses exclusively associated with lying. There is no unique tone of voice, no distinctive rhythm to the heartbeat, no precise change in blood pressure, and no signature pattern of neural excitation in the brain. Without such a clear signal to detect, these technologies cannot produce a trustworthy method of determining when the subject is lying.