Factors that facilitate or impair kinesic and vocalic nonverbal behaviors during interpersonal deception

This chapter presents results of an original interactive experiment in which truthful or deceptive interviewees were highly motivated (or not) and interviewed in one of three interaction modalities: face-to-face, audio, or text. Participants committed or observed a mock crime and then were interviewed by trained interviewers. Motivated interviewees became more animated facially and posturally and used more vocalized pauses and dysfluencies, regardless of veracity. Deceivers reduced gestures and movement and used more vocalized fillers, which became more prevalent over time. Deceivers reported higher motivation, negative arousal, cognitive effort, and behavioral control than truth tellers, especially in nonverbal modalities. Adaptation across phases of the interview challenges overreliance on nonverbal behaviors as deception signals.