Memon, A., & Gabbert, F. (2003). Unravelling the effects of sequential presentation in
culprit-present lineups. Applied Cognitive Psychology, 17, 703-714.
It has been found that sequential testing reliably reduces the number of false alarms that are made in eyewitness identifications, however, they also reduce the number of correct identifications. This study seeks to address what happens in sequential vs. simultaneous lineup presentations when there had been a change in the target’s appearance with both younger and older witnesses. The author’s predict a lowered choosing rate in sequential presentation when the target’s appearance has been changed, because the change in appearance reduces the overall familiarity of the target and sequential presentation forces the participant to adopt a more “absolute” judgment. Thus, if the familiarity of the face is lowered, there is less of a chance that it will meet the criterion set to be accepted as the previously seen face.
Methods
Both young and older adults participated in the study. The participants viewed a short film of a female (in a ponytail) committing an opportunistic crime (stealing money from an unlocked car). After watching the video, participants engaged in some filler tasks, and then were asked to write a detailed description of the target. After this, participants were given another set of filler tasks. After these tasks, the participants engaged in the identification task with one of four lineups (simultaneous or sequential and ‘same appearance’ (everyone with ponytails) or ‘changed appearance’ (everyone with their hair down)).
Results
Mean accuracy was 39.4% with older adults being less accurate (23.8%) than younger adults (52%). Younger adults made more hits, fewer false alarms, and more incorrect rejections when compared to older adults.
Mean accuracy was 48% with simultaneous lineups and 31% with sequential lineups. Fewer people made a choice with sequential lineups (58% compared to 75%).
Mean accuracy for same appearance was 43% whereas mean accuracy for changed appearance was 35%.
Changes in appearance significantly increased the number of incorrect rejections for younger adults, but not for older adults.
Younger adults recalled significantly more correct details about the target and fewer details. Young adults were also more confident before and after the identification.
Interestingly, self reports of using an absolute judgment strategy were associated with more erroneous responses on the identification task.
Discussion
When a sequential test is used and the target’s appearance has changed, absolute judgments might be leading to a decline in correct identifications (and choosing anyone). This effect might be even stronger when the delay is longer (or with a stronger change of appearance). Older adults were not impaired with the sequential testing, however, and that might be because decisions based on familiarity (as opposed to the recollection processes engaged in by younger adults more often) are not as affected by minor changes in appearance. In conclusion, the authors advise policy makers not to advocate sequential testing until the conditions are better understood.