Verdict in on Jury Deliberations
By Shari Seidman Diamond

Shari Seidman Diamond is Howard J. Trienens Professor of Law and Professor of Psychology at Northwestern University School of Law in Chicago and a Senior Research Fellow, American Bar Foundation. She can be contacted at>
Jury deliberations are the subject of much speculation, in part because they are not generally open to scrutiny. An opportunity to study what juries do behind closed doors arose when Arizona courts wanted to evaluate an innovation that allows jurors to discuss the case among themselves during breaks in the trial—a contrast to the usual practice of admonishing jurors to refrain from discussing the case until the end of the trial. The Arizona Judiciary permitted a team of researchers—Shari Diamond, Neil Vidmar, and Mary Rose—to conduct an experiment. With the consent of the litigants, attorneys, and jurors, we assigned trials to either allow or not allow juror discussions. We were also permitted to videotape the deliberations of the fifty civil juries involved. Participants were promised that the tapes would be viewed only by the researchers and only for research purposes. The results of the evaluation revealed some of the advantages (e.g., jurors found expert testimony easier to understand) and no evidence of the disadvantages (e.g., plaintiff advantage, premature closure) that proponents and critics of the discussions innovation had predicted.
In subsequent research, Mary Rose and I analyzed this unique data set to map the contours of jury deliberations. The picture of the civil jury that emerges is both more and less orderly than previous accounts would suggest. Jurors actively process the information they receive in the courtroom and apply commonsense norms of behavior to evaluate the reasonableness of behavior and sort out competing claims. They regularly draw on their personal histories and experiences to determine both the acceptable standard of behavior (e.g., what would constitute negligence) and what behavior actually occurred.
Previously neglected in research based on jury simulations and posttrial interviews is the importance of trust in juries’ decision making. Recognizing the adversarial nature of the courtroom setting, jurors scrutinize the sources of information they receive, looking for cues that witnesses and attorneys can be trusted. Jurors evaluate not only the credentials and experience of expert witnesses, but also the content of their testimony. They rely on and test each other’s impressions, often correcting errors in recall and inference. Juries also struggle with some of the judgments they are asked to make and the tools, such as jury instructions, they are expected to use to reach those judgments. Generally jury interactions are not part of a mechanical decision-making process but rather a series of negotiations that can be both messy and creative.
A common assumption about juries is that jurors begin deliberations with strong verdict preferences that are expressed in an immediate vote. After the vote reveals what the majority prefers, the majority then browbeats or otherwise persuades the minority to come around to its verdict. Actual civil jury deliberations are far more complicated. Deliberations rarely begin without disagreement and ambiguity. Early calls for votes are common, but most of them do not result in a clear majority or unanimous verdict. Moreover, voting occurs on a variety of different topics, not just on liability and damages. For example, the jurors may vote on whether they agree that there was an actual obstacle on the road at the time of the accident, as the plaintiff claimed.
The biggest challenges for juries are expert testimony and jury instructions, and both attract substantial effort and attention from the jurors. The most persuasive experts are clear communicators who do not obfuscate, either intentionally or inadvertently. Similarly, the jury instructions that provide the most effective guidance during deliberations are those that present information clearly and in an orderly way.
The jury is both a cultural icon and favorite scapegoat, sometimes put on a pedestal and other times charged with being biased and incompetent. The real jury revealed in our analyses of the approximately 80,000 comments jurors made during these deliberations is more accurately described as an active problem solver, vigorously engaged in grappling with the conflicting evidence to produce a plausible account of the events that led to trial.