PÄR ANDERS GRANHAG
Many people are fascinated by deception. Grand liars often become famous (e.g., Nick Leeson, who destroyed the 200-year-old Barings Bank), and a lie told by an already-famous person is often considered grand (e.g., Bill Clinton lying about his affair with Monica Lewinsky). Books with covers that promise some easy tricks to reveal liars may sell well, although the cover promises more than the authors can deliver. This general interest in deception is mirrored in the field of psychology and law, and intense research efforts over recent years have resulted in an impressive corpus of knowledge on deception and its detection (for recent overviews, see Granhag & Strömwall, 2004a; Vrij, 2000a). In this chapter we examine some of the latest research findings and explore what scientific psychology can tell us about the detection of deception. We focus mainly on research that has been conducted within the framework of "psychology and law" and pay less attention to related topics, such as deception in everyday life (DePaulo, Kashy, Kirkendol, Wyer, & Epstein, 1996), and deception in close relations (DePaulo & Bell, 1996).
The study of deception spans many of psychology's subdisciplines. For example, to understand why a liar's internal states might translate into certain nonverbal behaviors, it is necessary to study emotion and physiological psychology; to be able to argue why the verbal content of a true statement might differ from a false statement, we must study memory; in order to explain why people with a certain facial appearance are judged as liars more often than others, we must study social psychology. The full list is much longer, but the point is that a student of human deception needs to be acquainted with different domains within psychology.
Almost on a daily basis, people are forced to reflect and decide upon