Prevalence estimates as priors: Juror characteristics, perceived base rates, and verdicts in cases reliant on complainant and defendant testimony

Abstract

Jurors often have to make decisions about whether they believe a complainant's or defendant's account of an event. However, the relative ambiguity of cues in testimony creates a situation where juror evaluations can vary significantly. As a result, in cases heavily reliant on testimony there is a particular likelihood that juror characteristics will be associated with verdicts, and it is important to understand these associations. This research investigates the relationships between two juror characteristics—gender and cultural worldviews—and verdicts in two such cases, and the potential for those relationships to be explained by differences in perceived prevalence of alleged events acting as prior probability judgements. As predicted, results show significant relationships between gender and cultural worldview and verdicts and show that these relationships are mediated by differences in underlying prevalence estimates. These findings have important implications for understanding associations between juror characteristics and verdicts, and related policy.