Halfe the world knowes not how the other halfe lies: Investigation of verbal and non-verbal signs of deception exhibited by criminal offenders and non-offenders.

Purpose. This study examined the verbal and non-verbal behaviours exhibited by criminal offender and non-offender participants while they related planned truthful and deceptive accounts about emotional autobiographical events. Methods. In a 2 x 2 (participant group x veracity) quasi-experimental design, offenders (N = 27) and university students (N = 38) provided videotaped accounts of four autobiographical emotional events: two honest and two fabricated (counter -balanced). Patterns of behaviour exhibited during the truthful and the deceptive accounts were then compared. Results. In general, offenders and non-offenders showed similar patterns of deceptive behaviour. Deceptive accounts by both groups contained fewer details than honest accounts. Deception was associated with an increase in illustrator usage and self-manipulations; however, univariate analyses indicated only that offenders exhibited significantly more self-manipulations when lying. A significant interaction emerged in which offenders showed a reduction in smiles when lying about the emotional events, while students showed no difference. Conclusions. Offenders and students showed similar patterns of lying on most cues. However, unlike non-offenders, offenders smiled less and showed an increase in self-manipulations when lying. We theorize that offenders may have been aware that smiling and laughing are negatively related to perceived credibility in the speaker and used self-manipulations to distract listeners from the content of their lies. [ABSTRACT FROM AUTHOR]