Detailed information mitigates confidence inflation

ABSTRACT

Jurors distrust eyewitness testimony when eyewitness confidence is inflated between the incident and identification in court. Nevertheless, jurors may view inflated-confidence testimony as reliable if the eyewitness gives a justification for the inflation. Researchers have not examined how this ‘recovery of eyewitness credibility’ is affected by specific features of the justification (i.e. degree of detail). In Experiment 1, we manipulated the degree of detail in post-confidence-inflation eyewitness justifications containing information related to a witnessed criminal. We examined the effects of such justifications on participants’ ratings of the eyewitness testimony. Although highly detailed but inconsistent eyewitnesses who gave a related justification were not able to fully recover their credibility, we found that they showed reduced credibility loss relative to eyewitnesses who gave a less detailed justification or no justification. In a second experiment, we investigated the possibility that an eyewitness with inflated confidence could recover their credibility with a justification containing information unrelated to the criminal. Interestingly, we found that even when the justification was unrelated to the criminal, highly detailed but inconsistent eyewitnesses could mitigate some of their credibility loss. Implications for the mechanisms underlying eyewitness credibility recovery, and their ramifications for real-world cases are discussed.

KEYWORDS:

• Eyewitness confidence
• inconsistent eyewitness
• confidence inflation
• eyewitness testimony
• eyewitness credibility

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 We report analyses for the remaining characteristics in the Supplementary Material.

2 Determined via power simulations (10,000 simulated t-tests per effect size, with N fixed at 68).

3 Our data are available on OSF (https://osf.io/59w3d/).

4 Inclusion of these participants in analyses did not change the overall pattern of results.

5 As mentioned above, we also conducted exploratory analyses of four additional aspects of eyewitness credibility. We report results for these in the Supplementary Material Tables S1 and S2.

6 See also Supplementary Material Tables S1 and S2 for detailed NHST ANOVA and pairwise results for all eight eyewitness characteristics.

7 Inclusion of these participants in analyses did not change the overall pattern of results.

8 See also Supplementary Material Tables S3 and S4 for detailed NHST ANOVA and pairwise results for all eight eyewitness characteristics.