Interpersonal Deception: IX. Effects of Social Skill and Nonverbal Communication on Deception Success and Detection Accuracy

Interpersonal Deception Theory (IDT) posits that socially skilled individuals are better able to project truthful demeanors and evade detection than are unskilled individuals. IDT also predicts that social skills benefit receivers, making them better able to detect deception. Past research by Riggio, Thcker, Throckmorton, and Widaman in 1987 (in two separate studies) has shown that socially skilled individuals emit nonverbal behaviors that enhance believability. The present study extends Riggio's findings by investigating how social skills and nonverbal communication work in concert to predict three forms of deception/detection success: believability, accuracy, and bias. Acquainted and unacquainted dyads participated in interviews in which interviewees (senders) answered two questions truthfully and then used falsification, equivocation, or concealment to deceive on the remaining 13 questions. Results confirmed that as sender social skills increased, believability increased and receiver detection accuracy decreased, especially during equivocation. Skilled senders were more fluent and less hesitant. Senders were more believable, and truth biases were higher, if senders displayed greater involvement, positive affect, fluency, and composure and used a concealment strategy. Hesitancy was also implicated in a complex way. Only one dimension of receiver skill improved accuracy. Receivers were also more accurate if senders were less fluent.