Impact of Disguise on Identification Decisions and Confidence With Simultaneous and Sequential Lineups

Objective: Prior research indicates disguise negatively affects lineup identifications but the mechanisms by which disguise works have not been explored and different disguises have not been compared. We investigated how two different types of disguise, four levels of varying degrees of coverage, and lineup type influence eyewitnesses' identification decisions, accuracy, and confidence. Hypotheses: We predicted that identification accuracy would decrease as the disguise covered more of a perpetrator's face. We also predicted that type of disguise-stocking mask versus sunglasses and/or toque (i.e., knitted hat)-would influence identifications, but we had conflicting predictions about which disguise would impair their performance more. Method: In two experiments (Ns = 87 and 91) we manipulated degree of coverage by two different types of disguise: a stocking mask or sunglasses and toque. Participants viewed mock-crime videos followed by simultaneous or sequential lineups. Results and Conclusions: 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 meta-cognitions 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. Public Significance Statement In two experiments we tested how differing types and degrees of disguise influence eyewitness lineup decisions and confidence. When perpetrators were disguised (versus not disguised), identifications of guilty suspects and rejections of lineups containing innocent suspects decreased. Generally, these effects were stronger when more of the perpetrator's face was covered but we also note that (1) sunglasses had a greater effect than a hat and (2) a stocking obscuring two-thirds of a perpetrator's face was as effective as one obscuring a perpetrator's entire face. Also, eyewitnesses may not fully appreciate how much a disguise influences their accuracy: choosing from lineups decreased more slowly than accuracy as degree of disguise increased. The effects of disguise on identifica