Eyewitness confidence and decision time reflect identification accuracy in actual police lineups.

Abstract

Objective: Although there are many lab-based studies demonstrating the utility of confidence and decision time as indicators of eyewitness accuracy, there is almost no research on how well these variables function for lineups in the real world. In two experiments, we examined confidence and decision time associated with real lineups that had been conducted using research-based recommendations. Hypotheses: We expected that how confident an eyewitness sounded and how quickly that eyewitness made their identification would be associated with whether that eyewitness identified a suspect or a filler. We also hypothesized that people’s interpretations of eyewitness confidence could be easily influenced by additional, biasing information. Method: Using audio recordings of these lineups, we examined (a) participants’ subjective ratings of how confident an eyewitness sounded at the time of the identification and (b) objective data regarding how quickly the eyewitness made the identification decision. We also manipulated what additional information, if any, eyewitnesses received in Experiment 2. Results: In both experiments, decision time and confidence predicted whether the eyewitnesses identified the suspect or a known-innocent filler, and when decision time and confidence diverged, it is likely that the eyewitness identified a filler. In Experiment 2, we found that people’s interpretations of eyewitness’s confidence statements could be biased. When observers believed that the witness picked a filler rather than a suspect, or vice versa, this changed how confident they thought the witness sounded. Conclusions: Confidence and decision time should both be collected when administering real lineups, but objective decision time data may be the most useful because people’s perceptions of confidence are easily altered.

In their own words: Verbalizations of real eyewitnesses during identification lineups.

“…This is an addition to the two previous categories of estimator and system variables (Wells, 1978) that have long-defined factors that may directly influence witness accuracy. Quigley-McBride and Wells (2023) found that an accurate witness is likely to be faster and appear more confident than an incorrect eyewitness as long as the identification procedure was conducted under conditions of pristine system variables. The current data demonstrate the potential usefulness of witness comments as one additional reflector variable.…”

Lay (mis)perceptions of suspect-identification accuracy from biased and unbiased lineups.

“…Although laypersons appear insensitive to variables that affect suspect-identification accuracy, there is some evidence that laypersons are sensitive to variables that reflect suspect-identification accuracy. Reflector variables refer to behaviors emitted by an eyewitness during an identification procedure that covary with (or reflect) accuracy (Quigley-McBride & Wells, 2023; Smith & Wells, 2023; Wells, 2020). Laypersons perceive high-confidence suspect identifications as more likely to be accurate than low-confidence suspect identifications and fast suspect identifications as more likely to be accurate than slow suspect identifications (Dodson et al, 2021; Garrett et al, 2020, Slane & Dodson, 2022).…”

The Mechanisms of Memory versus the Federal Rules of Evidence

“…Eyewitness identifications are reliable on an initial test of uncontaminated memory using a properly administered lineup (Wixted et al, 2015;Wixted & Wells, 2017), and this is true even for actual eyewitnesses tested as part of real criminal investigations (Quigley-McBride & Wells, 2023;Wixted et al, 2016). In addition, a lineup rejection or a filler identification on an initial test provides evidence that the suspect is innocent (Wells & Olson, 2002;Wells, Yang, & Smalarz, 2015, Yilmaz et al, 2020.…”

“…The fact that the first identification procedure minimizes the chances of testing contaminated memory is what makes it special. Moreover, as has only recently come to be fully appreciated, how quickly and confidently a witness identifies the suspect on the initial test of uncontaminated memory is a powerful indicator of its reliability (Quigley-McBride & Wells, 2023;Wixted & Wells, 2017). Of particular interest here is the fact that witnesses are often appropriately uncertain when they misidentify an innocent suspect on the first test .…”