Absolute-judgment models better predict eyewitness decision-making than do relative-judgment models.

Abstract

When presented with a lineup, the witness is tasked with identifying the culprit or indicating that the culprit is not present. The witness then qualifies the decision with a confidence judgment. But how do witnesses go about making these decisions and judgments? According to absolute-judgment models, witnesses determine which lineup member provides the strongest match to memory and base their identification decision and confidence judgment on the absolute strength of this MAX lineup member. Conversely, relative-judgment models propose that witnesses determine which lineup member provides the strongest match to memory and then base their identification decision and confidence judgment on the relative strength of the MAX lineup member compared to the remaining lineup members. We took a critical test approach to test the predictions of both models. As predicted by the absolute-judgment model, but contrary to the predictions of the relative-judgment model, witnesses were more likely to correctly reject low-similarity lineups than high-similarity lineups (Experiment 1), and more likely to reject biased lineups than fair lineups (Experiment 2). Likewise, witnesses rejected low-similarity lineups with greater confidence than high-similarity lineups (Experiment 1) and rejected biased lineups with greater confidence than fair lineups (Experiment 2). Only a single pattern was consistent with the relative model and inconsistent with the absolute model: suspect identifications from biased lineups were made with greater confidence than suspect identifications from fair lineups (Experiment 2). The results suggest that absolute-judgment models better predict witness decision-making than do relative-judgment models and that pure relative-judgment models are unviable.