Eyewitness Descriptions, Accuracy of

Quantity versus Quality of Person Descriptions

Numerous archival studies have examined the quantity and quality of person descriptions provided in real cases. On average, witnesses tend to provide between 7 and 10 descriptors, and these descriptors tend to be quite consistent (or congruent) with the defendant who is subsequently identified. Unfortunately, the vast majority of descriptors provided by witnesses are general, including characteristics such as gender, race, [Page 286]age, height, weight, build, and complexion. Aspects of the clothing worn by the perpetrator are also frequently mentioned, but such features provide only a brief opportunity for use in identifying a suspect in the immediate aftermath of a crime. More specific facial features (such as eye color, hair color or style, and face shape) are rarely mentioned by witnesses, and those that are included tend to focus on the upper portions of the face. Taken together, witnesses appear to provide an accurate general impression of the perpetrator but often fail to include more specific facial details. Laboratory studies of witness descriptions tend to concur with studies of real witnesses, indicating that although witnesses generally provide accurate descriptions, they rarely include descriptors that might be useful for individuating a target face.

Factors That Influence Description Accuracy

Research suggests that a variety of cognitive and social psychological factors can influence the accuracy of a witness's description. First, encoding-based factors are those that occur around the time of the critical event when the witness interacts with or views the perpetrator. For example, low levels of illumination, greater distance between the witness and the perpetrator, a brief amount of time for viewing the perpetrator, the experience of stress or anxiety on the part of the witness (sometimes based on the presence of a weapon), and a witness under the influence of alcohol or drugs have all been shown to reduce the accuracy and completeness of person descriptions. Second, a subset of factors may occur between the time of encoding and retrieval of the description (i.e., during the retention interval) to influence the accuracy of a witness's description. For example, longer delays between encoding and retrieval have been shown to significantly reduce the quality of descriptions provided by witnesses, and exposure to “misinformation” (as described later in this entry) has been demonstrated to significantly impair a witness's memory and thereby his or her person description. Finally, certain characteristics of the witness can influence the quality of his or her person description. In particular, adults tend to provide more detailed descriptions than do children, though few differences in the accuracy of person descriptions have been noted between these two populations. Similarly, young adults are superior at recalling person descriptions when compared with middle-aged and elderly adults. Interestingly, unlike the cross-race effect in face identification, few differences in accuracy have been noted when individuals attempt to describe faces of another, less familiar race or ethnicity.

...