Conduct and its consequences: attempts at debiasing jury judgments

Jurors in negligence cases are supposed to judge a defendant by the reasonableness of his or her conduct and not by the consequences of that conduct. But several studies have shown that a cognitive heuristic known as hindsight bias can skew post hoc judgments of some prior behavior. Thus, jurors who must evaluate the actions of a defendant may be influenced inappropriately by the consequences of those actions. A complementary problem arises when jurors must evaluate the injuries incurred by the plaintiff. Here, jurors' knowledge about the defendant's allegedly negligent conduct can proactively influence their assessment of the plaintiff's injuries and determination of damages. The purpose of the present study was to examine the effectiveness of two procedural techniques intended to reduce or eliminate the impact of hindsight bias in negligence cases--multiple admonitions from a judge about the proper use of evidence--and bifurcation (actually withholding irrelevant evidence from jurors). We presented a re-enacted automobile negligence trial to 355 jury-eligible adults drawn from the community, varied the evidence and instructions that they heard, and measured liability judgments and damage awards from individual jurors both before and after deliberating, and from juries. Results showed that admonitions were generally ineffective in guiding jurors to the proper use of evidence but that bifurcation was relatively more effective. Deliberations had no curative effect on jurors' misapplication of evidence.