Eyewitness age and confidence determining outcomes for juror decision-making in robbery cases

Abstract

Eyewitness performance has been shown to have a wide variety of inaccuracies. Jurors often view eyewitness testimony as an accurate recollection due to the tendency to rely on automatic decision-making processes. Jurors’ perceptions of the age and confidence of eyewitnesses may be moderated by jurors’ heuristics or stereotypes. Proper judicial instructions may become critical to mitigate these influences on verdict decisions by engaging effortful thinking. This study aimed to examine the impact judicial instructions have on reducing the reliance on eyewitness characteristics for verdict decision-making. It was hypothesized that simple instructions would reduce the reliance on age and confidence to determine guilty verdicts. Fifty-eight participants were randomly assigned to a simple instruction (n = 29) or standard instruction (n = 29) condition. Participants were presented with four cases of highly confident and less confident child and older adult eyewitnesses. Results from a 2 × 2 × 2 mixed analysis of variance (ANOVA) indicated there was a significant main effect of confidence F(1,56) = 11.28, p = .001 for both the standard instruction condition F(1,56) = 68.17, p < .001 and simple instruction condition F(1,56) = 12.30 p < .001. Jurors’ reliance on confidence heuristics was demonstrated in the standard instructions while the simple instruction mitigated the reliance on confidence. This finding implies that simple instructions engage effortful thinking which allows for the reduction of the confidence heuristic. Future research should focus on replicating the findings with a larger sample size to determine if simple instructions aid in reducing age biases.