The use of so-called “lie detectors” to solve crimes and gain convictions has been largely overstated by the media and the big screen. As a matter of fact, many states don’t allow the results of a polygraph test to be admitted in court at all. The fact is, they are unreliable. Their unreliability is widely recognized by criminal justice professionals (aside from the polygraph administrators) but police agencies continue to use them.
Polygraph machines work by measuring certain physical qualities and responses, namely patterns in your heart rate. As questions are read, the test administrator analyzes these patterns and reportedly determines whether you are being honest or not. But despite what these analysts would have you believe, it’s not an exact science. [Read more…]