Person descriptions and person identifications: Verbal overshadowing or recognition criterion shift?

Abstract

In order to test rival theoretical accounts of the verbal overshadowing effect, participants (N=144) either gave no description or provided written descriptions after viewing a crime on video. Half of the describers reread their target descriptions prior to attempting to identify the thief either in a target-absent or target-present lineup 1 week later. Rereaders showed a criterion shift, that is, they less frequently chose somebody from the lineup than the other two groups. Within rereaders, description accuracy and choosing were positively correlated whereas number of incorrect details reported were negatively correlated with choosing. For describers that did not reread their description, there was a significant positive correlation between description accuracy and identification accuracy, and a negative correlation between number of incorrect descriptors and identification accuracy. The results lend support to the decision criterion shift approach (Clare & Lewandowsky, 2004) and shed light on the decision processes underlying target description and identification.

Acknowledgements

We wish to thank Miriam Kirschner, Christina Almera, and Norman Koch for their help in data collection. This paper is part of Melanie Sauerland's doctoral dissertation conducted at Giessen University and part of it was presented at the annual meeting of the American Psychology-Law Society in March 2006.

This paper was supported by a grant from the Deutsche Forschungsgemeinschaft (German Science Foundation) to the second author.

Notes

¹Note, however, that identification decisions are binary and therefore no such tradeoff is possible.

²Note, however, describing and rereading are not the same; describing a person is the effort to verbally retrieve a visually encoded stimulus, whereas rereading the description merely reactivates the previously encoded verbal memory trace. One assumption is that both processes have a similar effect due to the VOE. Yet, the possibility that rereading has an associative effect in terms of context reinstatement should not be ignored.

³Using description accuracy as a predictor for identification accuracy has been criticised in previous research (Sporer, 1996; Wells, 1985) because the accuracy coefficient does not differentiate between more and less detailed descriptions. A description consisting of only one correct detail will obviously have a higher accuracy score (100%) than a description consisting of 10 details with 2 of them wrong (80%). However, the minimum of total descriptors provided by participants in our experiment was 7 (M=16.8; SD=4.1), which made analyses with description accuracy appropriate and justifiable.