To Tell the Truth

The device that is widely used to detect lies today, the polygraph, is simply too unreliable. It is too inaccurate for the results to be admissible in court cases. A 2002 report by the National Research Council concluded that the polygraph can’t distinguish innocent people from guilty ones. In response, the U.S. Department of Energy began relying less on the use of the polygraph to conduct security checks on its employees.

The polygraph measures changes in heart rate, breathing, and other physiological responses to stress. In t.....