The influence of juror’s level of moral reasoning and the nature of closing arguments in determining the verdict in a civil case: A report of two experiments.

Bernard, J. L., Cohen, R., & Lupfer, M. (1985). The influence of juror’s level of moral reasoning and the nature of closing arguments in determining the verdict in a civil case: A report of two experiments. Law and Psychology Review, 9, 93-102.

Conducted 2 experiments to investigate the relationship between the level of moral reasoning of jurors and their decisions and evaluated the differential impact on jury verdicts of closing arguments framed to reflect conventional or postconventional moral reasoning. All Ss were administered the Defining Issues Test (DIT), a measure of principled thinking (PT). Ss were designated as high- or low-PT according to scores on the DIT; the higher the PT score obtained, the more S was thought to be inclined toward postconventional moral reasoning. In Exp I, 66 undergraduates were selected and grouped into 6-member juries: 4 high-, 3 low-, and 4 mixed-PT juries. Ss witnessed a videotape of a simulated trial. High-PT juries found unanimously for the defendant, while over two-thirds of the mixed jurors and almost all of the low-PT jurors found for the plaintiff. In Exp II, 126 undergraduates served as Ss. Results of Exp II confirm those of Exp I in showing that the S’s level of moral reasoning affected his/her ballot. Findings show that the jurors’ characteristic approach to the solution of moral questions carried over into the courtroom and that it profoundly influenced verdicts. Large impact of juror moral reasoning on jury verdicts; juries composed of jurors with postconventional moral reasoning more likely to find defendant not liable than juries made up of jurors with conventional reasoning and mixed juries. <2>Main effect of composition replicated; leniency shift occurred in juries exposed to postconventional closing arguments from plaintiff and conventional arguments from defense attorney.

http://psycnet.apa.org/psycinfo/1986-09019-001