The Effects of Verbal Descriptions on Eyewitness Memory: Implications for the Real-World

The criminal justice system depends on verbal accounts of crimes. Can the act of reporting a crime harm eyewitness memory for the perpetrator of that crime? The answer is yes according the verbal overshadowing effect. The verbal overshadowing effect describes the finding that memory is adversely affected after verbally describing a previously presented item (e.g., face). Often in studies of the verbal overshadowing effect, participants watch a video of a mock crime, describe the perpetrator (verbal condition) or engage in another task (control condition). In many of these studies, including the original (Schooler & Engstler-Schooler, 1990) and replication studies (Alogna et al., 2014), memory for a perpetrator is tested on target-present lineups, and, if described, the perpetrator is less often identified. However, it is unknown whether or not the lower identification rate is due to reduced discriminability or due to more conservative responding after providing a description. The verbal overshadowing effect ought to be defined as a reduction in discriminability, which is measured by taking both the correct ID rates (from target-present lineups) and false ID rates (from target-absent lineups) into consideration. Another important and independent measure is the reliability of identifications (i.e., the positive predictive value of a suspect identification made with a given level of confidence). As matters stand, the take-home message is this: too little information currently exists to allow for an assessment of the effects of verbal descriptions on discriminability and reliability; thus, the field is not yet in a position to offer clear guidance for practice in the criminal justice system.