Lie Detectors

Lie detectors have been used for a long time now and people are very familiar with it due to media attention. People assume that the science behind lie detectors is actually true. Lie detectors in reality are based off of psychological manipulation of the person under the lie detector test to possibly confess, because they think it may uncover the truth. It's basically a voodoo psychology.

The problem with lie detectors is the fact that it measures heart rate, blood pressure, respiration, and skin response and conductivity. So how do these things correlate with deception? It seems that it measures anxiety more than anything. So the whole basis for lie detectors is the fact that anxiety brings out a sort of guilty knowledge?

There is no correlation that exists with these assumptions that anxiety = guilt. There is no scientific testing that shows this and not consistently enough to prove deception. People can be anxious that they are lying or that they are afraid the person examining them thinks they are lying. It also fails to consider people who can beat the lie detector test such as psychopaths who do not have anxiety over heinous acts.

This site discusses all of this

http://www.science20.com/gerhard_adam/pseudoscience_lie_detectors-93551

Additional info:

http://polygraphreality.wordpress.com/