To what extent does post-identification feedback translate into witness behaviour?

Abstract

When eyewitness receive feedback implying they have accurately identified the perpetrator from a lineup, it boosts their confidence and possibly distorts their memory. Most research investigating this "post-identification feedback effect" (PIF effect) suggests the feedback changes eyewitness' retrospective memory of their actual experiences. But it remains unclear to what extent this feedback might change the eyewitness's subsequent behaviour. Across four experiments, we addressed this issue. We investigated whether people who received confirming feedback were more likely to provide recorded or written statements as evidence for an ongoing trial. Across the four experiments, we replicated the basic PIF effect. But we found no consistent evidence that these same people were more willing to offer their experimental data nor to submit a statement about what they saw. We did find preliminary evidence that people who received confirming feedback submitted longer statements. Taken together, these findings have theoretical implications establishing boundary conditions on the influence of feedback. On the practical side, these findings suggest caution in extrapolating the influence of PIF beyond a relatively small set of retrospective reports, beliefs, and inclinations.