Telling and Detecting Lies

This Blog reviews nonverbal, verbal and physiological cues to deception. In particular, we will discuss how liars behave, what they say, how they physiologically react and how good professional lie detectors (police detectives, polygraph examiners and so on) are at detecting truths and lies while paying attention to such cues. The chapter reveals that professional lie catchers, among others, are to some extent able to detect lies by examining behavior, speech content or physiological reactions. However, as this chapter will also show, no perfect lie detection test exists, and lie detection experts make wrong judgments on a regular basis. We will discuss several problems and pitfalls lie detectors typically face, but we start with some background information, such as a definition of deception, the types of lie people tell, the reasons why people lie and how frequently people tell lies.