Dateline: August, 2007, Issue 1
Legally, the severity of a plaintiff's injury is irrelevant to decisions about liability. Although injury severity is directly relevant to the issue of compensation, an effect on the prior determination of liability would constitute an extralegal bias.
Bornstein (1998) conducted two studies examining whether the severity of a plaintiff's injury affected jurors' verdicts of liability. All jurors read a summary of a personal injury case against a drug manufacturer in which the sole fact-in-issue was whether the defendant's birth control pill caused the plaintiff's injury. For some jurors, the plaintiff was severely injured (she had ovarian cancer, detected late, both ovaries removed, unable to have children, poor prognosis, short life expectancy). For other jurors, the plaintiff was not as severely injured (she had ovarian cancer, detected early, one ovary removed, still able to have children, excellent prognosis, minimal chance of recurrence).
The research found that jurors who read about the more severely hurt plaintiff more often judged the defendant liable, despite evidence of liability being the same for both the severely and less severely injured plaintiffs.
Importantly, injury severity affected jurors' liability verdicts only insofar as jurors had positive feelings toward the plaintiff or negative feelings toward the defendant. Additionally, injury severity had no effect on jurors' liability verdicts when jurors could not award damages.
In sum, a defendant facing a severely injured plaintiff is found liable more often when (a) jurors feel sympathy for the plaintiff or anger at the defendant, and (b) jurors' make simultaneous, rather than bifurcated, decisions about causation and compensation.
Source Bornstein, B. H. (1998). From compassion to compensation: The effect of injury severity on mock jurors' liability judgments. Journal of Applied Social Psychology, 28, pp. 1477-1502.