According to a National Security Agency (NSA) whistle-blower, Russell Tice, it is possible to beat a polygraph by skewing the initial data and forcing strong reactions in response to known lies. He also suggests daydreaming while lying to create the necessary physiological response that indicates relaxation. In an episode of the Discovery show "Mythbusters," one host beat a functional MRI polygraph by focusing on his fears to stimulate blood circulation in his brain.
While NSA spokeswoman Vanee Vines insisted that polygraphs are a vital tool in the NSA's vetting process, the American Psychological Association (APA) does not believe that lie detector tests can accurately detect falsehood. At best, polygraphs allow the interviewer to infer deception based on nonstandardized physiological reactions, which skilled or informed people can manipulate to a certain extent. Tice also stated that by 2012, he believed that polygraphs had become significantly easier to pass with more predictable questions thrown his way.
The APA states that polygraphs work under the assumption that liars are more likely to fear control questions rather than relevant ones, with the contrast between the two serving to indicate deception or truth. However, there is no evidence of a consistent physiological reaction to falsehoods, and studies have failed to distinguish between the placebo effect and actual accuracy of the test.