Trial by Jury: Psychological Research Contributions to an Enduring Legal Institution

Abstract

Legal decision-making is a complex psychological process with weighty consequences. This has led some to question why a group of lay citizens with no relevant background or training in the law should decide legal cases. This chapter addresses these concerns by summarizing psychological theory and research that sheds light on how jurors approach their task and that confirms the general soundness of the jury as a fact-finding body. The chapter outlines current psychological models of decision-making that map out how individual jurors and juries come to their decisions in civil and criminal trials. It describes how the diversity of juries contributes positively to the jury’s fact-finding competence and the fairness of its decisions. The chapter also presents evidence about the effectiveness of various jury reforms, from the jury’s size and decision rule, to trial aids such as notetaking and question-asking, to instructions on the law and on implicit biases. The chapter concludes with suggestions for future jury research, including research on global systems of lay legal decision-making.