LINEUP SIZE AND NUMBER OF CUES: WHEN BIGGER ISN’T BETTER

Larger lineups could protect innocent suspects from being misidentified; however, they can also decrease correct identifications. Bertrand (2006) investigated whether the decrease in correct identifications could be prevented by adding more cues, in the form of additional views of lineup members’ faces, to the lineup. Adding these cues was successful to an extent. The current series of studies attempted to replicate Bertrand’s (2006) findings while addressing some methodological issues—namely, the inconsistency in image size as lineup size increased. First, I investigated whether image size could affect face recognition (Chapter 2) and found it could, but that it also affected previously-seen (“old”) versus previously-unseen (“new”) faces differently. Specifically, smaller image sizes at exposure lowered accuracy for old faces, while these same image sizes at recognition lowered accuracy for new faces. Although these results indicate that target recognition would be unaffected by image size at recognition (i.e., during a lineup), lineups are also comprised of previously-unseen faces, in the form of fillers and innocent suspects. Because image size could affect lineup decisions, as it could become more difficult to realize fillers are previously-unseen, I decided to replicate Bertrand (2006) while keeping image size constant in Chapters 3 (simultaneous lineups) and 4 (simultaneous-presentation, sequential decisions). In both Chapters, the integral findings were the same: correct identification rates decreased as lineup size increased from 6- to 24-person lineups, but adding cues had no effect. The inability to replicate Bertrand (2006) could mean that the original finding was due to chance, but alternate explanations also exist, such as the overall size of the array, the degree to which additional cues overlap, and the length of the target exposure. These alternate explanations, along with directions for future research, are discussed in the following Chapters.