Getting into the minds of pairs of liars and truth tellers: An examination of their strategies

We examined the strategies used by 20 pairs of liars and 20 pairs of truth tellers when they were given the opportunity to prepare themselves for an interview in which they would be questioned about their whereabouts during a given period of time. More lying than truth telling pairs prepared themselves for the interviews. The truth tellers and liars who did prepare themselves used different verbal strategies but the same nonverbal strategies. Regarding verbal strategies, truth tellers were predominantly concerned with telling everything they could remember. In contrast, liars thought of answers they could give to possible questions but also decided to be vague so that they would not contradict each other. Regarding nonverbal strategies, both truth tellers and liars tried to suppress nervous behaviours. These findings explain why truth tellers are typically more detailed than liars but also why liars are typically equally consistent as truth tellers, at least when answering questions they have anticipated. Implications for interview techniques to detect deceit are discussed.