A stability bias effect amongst deceivers

Research examining how truth tellers’ and liars’ verbal behaviour is attenuated as a function of delay is largely absent from the literature, despite its important applied value. We examined this factor across two studies in which we examined the effects of a hypothetical delay (Experiment 1) or actual delay (Experiment 2) on liars’ accounts. In Experiment 1 – an insurance claim interview setting – claimants either genuinely experienced a (staged) loss of a tablet device (n=40), or pretended to have experienced the same loss (n=40). Truth tellers were interviewed either immediately after the loss (n=20) or three weeks after the loss (n=20), whereas liars had to either pretend the loss occurred either immediately prior (n=20) or 3-weeks prior (n=20) to the interview (i.e., hypothetical delay for liars). In Experiment 2 – a Human Intelligence gathering setting – sources had to either lie (n=50) or tell the truth (n=50) about a secret video they had seen concerning the placing of a spy device. Half of the truth tellers and liars where interviewed immediately after watching the video (n=50), and half where interviewed three-weeks later (n=50) (i.e., real delay for liars). Across both experiments, truth tellers interviewed after a delay reported fewer details than truth tellers interviewed immediately after the to-be-remembered event. In both studies, liars failed to simulate this pattern of forgetting and reported similar amounts of detail when interviewed without or after a delay, demonstrating a stability bias in reporting.