How credible are lie detector tests?

Erasmus School of Economics

The FBI report into the allegations of sexual misconduct made against Supreme Court nominee Brett Kavanaugh is currently being read by the senators in the US Capitol building. Even though the report is secretive, it is subject to a lot of criticism regarding the scope of the investigation. Furthermore, because one of his accusers has taken a lie detector test, many Democrats now insist on letting Brett Kavanaugh take such a test as well. However, many people have doubts about the accuracy of these tests. Assistant Professor Sophie van der Zee tells us why these tests are in fact reliable.

Lie detection tests, also known as polygraph tests, record a number of different bodily responses which can then be used to determine whether someone is telling the truth. According to Assistant Professor Sophie van der Zee: "The polygraph, like any other lie detection technique, measures an indirect effect of lying. There's no human equivalent of Pinocchio's nose. But lying can increase stress, and with lie detection techniques you can measure the behavioural and physiological changes that occur when you feel stress." As such, polygraph tests do not measure deception or lying directly, but rather possible signs that a person could be deceiving the interviewer.


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Read the entire article on BBC News, d.d. 4 October 2018.