Rotenberg, K. J., Hewlett, M. G., & Siegwart, C. M. (1998). Principled moral reasoning and self-monitoring as predictors of jury functioning. Basic and Applied Social Psychology, 20, 167-173.
Seventy-eight undergraduate students who had been administered the Defining issues Test (DIT) and the Self-Monitoring Scale (SMS) participated as jurors in mock trials. Consistent with expectation, the students’ pretrial DIT Principled Moral Reasoning (PMR) scale scores predicted their (a) dominance of jury deliberations as rated by other jurors, (b) behavioral dominance of jury deliberations as shown by edification and advisement communication, and (c) functional influence over jury verdicts as shown by the association between their pretrial case judgments and jury verdicts. Students’ pretrial SMS Extraversion subscale scores predicted their dominance of jury deliberations, as rated by jury members and by serving as a foreman. PMR scores predicted dominance over jury deliberations and functional influence over jury verdicts independently of Extraversion scores. The reliable finding that individuals attaining the most advanced moral reasoning dominated juries and influenced their verdicts was interpreted as providing a positive view of the role the jury plays in the judicial process. Extraversion and moral reasoning predicted juror dominance in deliberation; pre-deliberation preferences for individuals with higher levels of moral reasoning were most strongly correlated with jury verdicts, but effect was not mediated by quantity of speaking.