Studies suggest that the college students tell an average of two lies per day. We all lie. This is the reason that there is such a large emphasis on lie detection. There are many different lie detection techniques: nonverbal behaviors, polygraph tests, guilty knowledge tests (GKT), brain fingerprinting, fMRI methods. Of all of these techniques, the polygraph test is one of the most popular. Ever since its creation in 1915, it has been used to detect lies and convict criminals. The polygraph test rests on the assumption of the Pinocchio response, which is defined as a perfect physiological or behavioral indicator of lying. Although the largest organization of polygraph examiners claims that the test is 98% accurate, the polygraph test produces a high rate of false positives. This means that there are many innocent individuals whom the test labels incorrectly, and some have estimated this rate to be 40% or more of individuals tested.
With such a high rate of failures, I wonder whether scientists and researchers will continue to place such high importance on the polygraph test alone. Because this test is based on the Pinocchio response, there have been many guilty people who have used countermeasures to pass, such as biting their tongue or curling their toes. There is an evident flaw in the polygraph test. Although very unlikely because people are so deceptive, I hope that we see a test created in the near future that is 100% accurate. To learn more about the history of the polygraph test, click here.