Let me share with you the experience I've had with polygraphs. A few years ago a friend and I happened to be near (a mile away from the starting point) a large forest fire. Essentially, it was started by some fireman doing some logging in their spare time. Since this fact was embarassing for local law enforement the ranger on the case cooked up a case file against me and my friend (mind you the fire cost the state 67,00 dollars, for which we would have been held liable if this farce had gone any further). I have shown this case file to many people who have laughed at it, it is full of contradictions, useless unrelated statements taken out of context and no factual evidence whatsoever. The ranger even tried to lie about which way the wind was blowing so he could place the start point in a more convenient spot. 

Anyway, I was strongarmed into taking a polygraph at a state police barracks. I was never told I had a choice. The room was well over 80 degrees and the windows were kept closed. I was asked many questions that had nothing to do with the case at hand. Questions about drug use, sexual habits and other private topics. these questions were peppered in among the real questions and often took me aback at their audacity. As soon as the real test started and they had gotten my "normal" measurements they started in with the innapropriate questions. Is it any wonder I failed the polygraph? After this I realized lawyers aren't just for guilty people and got one on my side. On the last day before the the statute of limitations ran out on the case the DA dropped it for lack of evidence. 

Later I was talking with my local gym owner, a good friend of mine. He remembered the polygraphers name and told me how he used to help powerlifters and bodybuilders pass drug tests for their meets. At the time an acceptable drug test for a competition could be a polygraph test about a person's use of steroids. This polygrapher administered such tests on his weekends. The meet directors paid him a flat rate to do the tests and for twenty extra dollars he would pass you regardless of your drug use. Some athletes started paying him extra to disqualify people and the practice got out of hand with counter bribes and all sorts of backstabbing. Eventually everyone got so sick of it they changed federations to one which required random chemical tests.

These experiences and more have led me to believe that polygraphy is as subjective as the motives of the person administering the test. Not only do they often have the power to lie about the results they can also influence the results by manipulating the environment of the test taker and the line of questions that are pursued. Someone has got to put an end to this absurd pseudoscience.