On the Applied Implications of the 'Verbal Overshadowing Effect'

摘要

Schooler and Engstler-Schooler (1990) found that participants who wrote out a description of the perpetrator's face after watching a simulated crime video were subsequently less likely to identify that perpetrator from a photo lineup compared to participants in a control condition (i.e., the correct ID rate was reduced). The first registered replication report in Perspectives on Psychological Science confirmed this verbal overshadowing effect (Alogna et al., 2014). Does this result indicate a reduced ability to recognize the person who was verbally described, or does it instead reflect more conservative responding? The answer depends on the still unknown likelihood of identifying an innocent suspect from a lineup (the false ID rate). Assuming the reduced correct ID rate does reflect memory impairment, should the legal system be advised to give less weight to a suspect identification if the witness previously provided a verbal description of the perpetrator? Intuitively, the answer is yes, but without knowing the false ID rate, it is unclear if a suspect identification following a verbal description should be given less weight or more weight. This is true even if the correct and false ID rates show that verbal descriptions impair memory. In our view, psychologists should withhold giving advice to the legal system about the effect of verbal descriptions on suspect identifications until the issue is investigated by including lineups that contain an innocent suspect.