How deception and believability feedback affect recall

While research suggests that telling lies can distort memory for the truth, the effects of receiving feedback about the believability about one's lies are not known. We hypothesised that participants who exaggerated the number of stolen items (vs. told the truth) in a mock insurance claim and then received feedback that their statement was believable (vs. not believable) would incorporate this lie into memory. In a two-phase between-subjects design, participants saw images of an office pre- and post-theft and were randomly assigned to report the number of stolen items accurately (truth-tellers) or exaggerate (liars). They were then randomly assigned to receive feedback that their statement was believable or not. Approximately two weeks later, participants' recall of the theft was measured. Liars and truth-tellers recalled a similar number of stolen items, but liars had less accurate recall for exactly which items were stolen. Liars (vs. truth-tellers) also made more omission errors. The majority of participants who fabricated additional stolen items (65.7%) incorporated one or more of these (false) items into their memory. Results suggest that source monitoring errors may lead fabricated details to be incorporated into memory. Although no effects of believability feedback were observed, recommendations for future researchers are discussed.