Police use of nonverbal behavior as indicators of deception

People rely on various sources of information when they form impressions about others. They could pay attention to various characteristics of the target person, such as gender (Hall & Carter, 1999; Stangor, Lynch, Changming, & Glass, 1992), age (Hargie & Tourish, 1999; Hummert, 1999), race (Brown, 1995; Ruby & Brigham, 1996), dialect (Giles & Johnson, 1986; Giles & Powesland, 1975; Street & Hopper, 1982), dress (Vrij, 1993), clothing (Frank & Gilovich, 1988; Vrij, 1997), and facial appearance (Bull & Rumsey, 1988). They also could examine what people actually say (speech content, Krauss & Chiu, 1998; Steller & Kohnken, 1989) or observe their behavior (DePaulo & Friedman, 1998). In this article we primarily focus on the impact of nonverbal communication on impression formation. Nonverbal behavior does not only include body language, such as movements people make, smiling, gaze behavior, etc., but also vocal characteristics, such as speech rate, speech pauses, uhms and ers, pitch of voice, etc. In addition, we primarily focus on a specific area within impression formation, which is the judgment about whether or not someone is lying (we will use the words deception and lying interchangeably). As Horvath, Jayne and Buckley (1994) pointed out, making judgements about the veracity of statements is an important aspect of police work.