Combatting a failure to report: Juror misconduct and the mum effect

Abstract

The purpose of this study is to examine strategies used in jury instructions to combat the mum effect in the context of jury misconduct. This study was conducted using a 2x3 experimental design employing three sets of typed jury instructions (e.g. Standard, Punitive, and Modified) and two videos of juror deliberations portraying the absence or presence of juror misconduct. Participants (N = 222) were randomly assigned into one of six experiment conditions in which they read one of three sets of jury instructions and completed measures examining constructs of punishment and clarity. They then watched a video of mock jury deliberations containing the absence or presence of jury misconduct and then completed a series of measures to examine perceptions of misconduct and reporting. The study found each of the three sets of jury instructions to be equally clear. The punitive instructions were found to be more punishing than either the standard or the modified jury instructions. However, there were no significant differences in reporting perceived misconduct across the three jury instruction conditions. Instead, participants who reported the perception of misconduct also tended to report the misconduct.