The effects of injury severity on jury negligence decisions.

Greene, E., Johns, M., & Bowman, J. (1999). The effects of injury severity on jury negligence decisions. Law and Human Behavior, 23, 675-693.

According to the laws of negligence, jurors’ liability decisions are to be influenced by the defendant’s conduct, but not by the severity of the plaintiff’s injuries. We conducted a jury simulation study to assess whether jurors reason in this manner. We manipulated the conduct of the defendant (reasonable, careless) and the severity of injuries to the plaintiff (mild, severe) in a simulated automobile negligence case. Jurors completed predeliberation questionnaires, deliberated to a verdict, and answered postdeliberation questionnaires. The defendant’s conduct had a strong impact on liability judgments, but evidence related to injury severity also had an effect, albeit smaller. We analyze these findings in the context of various cognitive and motivational theories.

Liability and responsibility judgments were related strongly to the defendant’s conduct but also related moderately to severity of plaintiff injury. Juries more likely to find defendant liable and responsible when defendant conduct was careless as opposed to reasonable and when plaintiff injury was mild as opposed to severe. Deliberation did not reduce contaminating influence of injury severity on liability verdicts.