Impact of disguise on identification decisions and confidence with simultaneous and sequential lineups.

Abstract

Prior research indicates that disguise negatively affects lineup identifications, but the mechanisms by which disguise works have not been explored, and different disguises have not been compared. In two experiments (Ns ϭ 87 and 91) we manipulated degree of coverage by two different types of disguise: a stocking mask or sunglasses and toque (i.e., knitted hat). Participants viewed mock-crime videos followed by simultaneous or sequential lineups. Disguise and lineup type did not interact. In support of the view that disguise prevents encoding, identification accuracy generally decreased with degree of disguise. For the stocking disguise, however, full and 2/3 coverage led to approximately the same rate of correct identifications-which suggests that disrupting encoding of specific features may be as detrimental as disrupting a whole face. Accuracy was most affected by sunglasses and we discuss the role metacognitions may have played. Lineup selections decreased more slowly than accuracy as coverage by disguise increased, indicating witnesses are insensitive to the effect of encoding conditions on accuracy. We also explored the impact of disguise and lineup type on witnesses' confidence in their lineup decisions, though the results were not straightforward.

Are multiple-trial experiments appropriate for eyewitness identification studies? Accuracy, choosing, and confidence across trials

“…We reanalyzed data reported in Mansour et al (2012) and included newly collected data using an almost identical methodology (total N = 8,376 lineup decisions). We summarize only the key factors of the earlier work; readers are encouraged to refer to Mansour et al for a more detailed methodology.…”

“…As in Mansour et al (2012), 1 The data from four participants from Experiment 1 and five participants from Experiment 2 of Mansour et al (2012) were not included in these analyses because they completed 32 (rather than 24) trials. As such, these participants saw different targets for the first 24 trials than were seen by the other participants.…”

“…The participants in the two experiments from Mansour et al (2012) were students at an Eastern Canadian University. The participants in Experiment 1 (N = 98) were randomly assigned to the toque and/or sunglasses condition of our disguise type manipulation, whereas the participants in Experiment 2 (N = 102) were randomly assigned to the stocking condition of our disguise type manipulation.…”

“…We later collected additional data from 158 participants (randomly assigned to the toque and/or sunglasses disguise [n = 78] or stocking disguise [n = 80] conditions) at a Western Canadian university using nearly the same procedures as Mansour et al (2012).…”

“…We excluded them from these analyses to remove additional noise from the data. The following ns reported represent those used in our analyses.Behav Res (2017) 49:2235-2254 2238 we manipulated degree of disguise and target presence within subjects and employed counterbalancing for these variables.Materials and procedure The materials (including videos and lineups) and procedure were the same as in Mansour et al (2012), with the exception of the 30-s delay between videos and lineups, during which participants viewed a Where's Waldo 2 image and answered related questions (e.g., BHow many people are sunburned in this picture?^). …”