Jury: Behavioral Aspects

In theory, jurors are expected to apply the law to the facts of the case. However, a verdict rarely reveals whether the jury has applied the judge's legal instructions, or whether the jury has applied the judge's instructions accurately. Thus, trial and appellate courts are left to assume that the jury has followed the judge's instructions when the verdict is consistent with the law under at least one possible interpretation of the facts. Questions about the jury's use of the legal instructions typically arise at the appellate level only in the context of concerns about whether the trial court has stated the legal standard accurately. If the statement of the law comports with the legal standard, questions are rarely raised regarding whether the judge conveyed the standard clearly enough to be correctly applied.

Jurors might fail to follow the judge's instructions on the law if they were either unmotivated or unable to apply the instructions. Empirical studies of the jury show that jurors see themselves as obligated to apply the law, and that they spend a significant portion of their time during deliberations discussing the law. Yet, there is also evidence that legal instructions as they are typically given often fail to provide jurors with helpful legal guidance. Nearly twenty years ago, Elwork, Sales, and Alfini examined juror comprehension of several frequently used jury instructions. They showed not only that comprehension was low, but also that it could be significantly improved if the instructions were rewritten using a combination of psycholinguistic tools and common sense.

More recent work has demonstrated additional ways to facilitate comprehension. The traditional approach to jury instructions is to tell the jury only what it is supposed to do, and to avoid directing attention to any matter that the jury should ignore. But failing to address the erroneous beliefs that jurors do have does not make those beliefs go away, and it does not neutralize them. For example, if jurors are worried about whether a defendant not sentenced to death will be eligible for parole, avoiding any mention of the parole issue during jury instructions can leave jurors believing that a swift release is likely. Jurors come to court with expectations, beliefs, and schemas that can powerfully affect perceptions, attention, and recall. When instructions fail to correct inaccurate legal impressions, they miss the opportunity to provide jurors with a meaningful legal framework.

Although the most common source of deviations from legal standards is a failure of the legal instructions to convey clearly what the appropriate legal standard is, jurors also may deviate from the path outlined in the instructions due to cognitive biases or motivational obstacles. Jurors admonished to disregard particular information may find it difficult to do so. Other legal instructions may ask the jurors to engage in mental gymnastics that are not easy to perform, for example, to use a defendant's criminal record only to assist in evaluating his credibility, but not as evidence of bad character; to forget that they learned about damaging evidence that the judge ruled inadmissible. Yet, jurors may be unwilling or unable to perform the required cognitive adjustments. A series of simulation experiments have illustrated that such inadmissible evidence can affect juror decisions. The remaining question is whether these failures are significantly less likely when the trier of fact is a judge, or whether they represent heuristic patterns of using information that neither a judge nor jury can overcome.

Finally, jurors may depart from the judge's legal instructions when the application of the legal standard to the particular case so substantially violates the jurors' sense of justice that they are persuaded to temper the letter of the law. This conduct has come to be known as "jury nullification." Kalven and Zeisel attributed most of the disagreements they found between judge and jury to evidentiary disputes, reporting that the jury is engaged in only a modest rewriting of the law in cases that are close on the evidence. Yet, even if it is rare, explicit jury nullification of the law plays a central role in conceptions of the jury and has been a source of extensive debate. Although courts have long recognized the power (as opposed to the right) of the jury to nullify, courts and commentators have disagreed about whether juries should be told about that power (United States v. Dougherty, 472 F.2d (D.C. Cir.1972); United States v. Thomas, 116 F.3d 606 (2d Cir. 1997)). Empirical research indicates that the distinction between the power and the right matters: when jurors are explicitly instructed that they have the right not to apply the law as the judge describes it, they are more willing to reach verdicts that temper the literal application of the law.