Suggestiveness in photospread line‐ups: Similarity induces distinctiveness

Abstract

AbstractThe present research examined whether line‐ups based on target (‘suspect’) face similarity are biased or suggestive. Four experiments are described in which subjects constructed photographic line‐ups by selecting foils similar in appearance to a target. Later, another group of subjects who had not seen the faces before (mock witnesses) were asked to pick out the targets from the line‐ups. All four experiments showed that mock witnesses selected the target significantly more often than expected by chance, thereby demonstrating suggestiveness. Three alternative line‐up construction methods were also evaluated. In these methods, foil selection was based not only on target similarity but also on similarity with one or more of the other line‐up faces. Results showed that alternative line‐up targets were not selected significantly more often than chance, suggesting that bias was reduced. An overall analysis showed that the alternative line‐ups were significantly less suggestive than target‐based line‐ups. The results indicate that foil selection procedures that incorporate foil‐to‐foil similarity produce fairer line‐ups than those exclusively based on target similarity.