Hindsight Bias in Reaction to the Verdict in the O.J. Simpson Criminal Trial

Abstract

Students estimated the chance that O.J. Simpson would be convicted or acquitted of murder and the likelihood of large-scale violence following conviction, at 3 points in time: 2 hr before the announcement of the not guilty verdict, 2 days after the verdict, and 1 week after the verdict. Within-subjects analyses revealed that estimates of the probability of conviction made 2 hr before the not guilty verdict were higher than estimates of prior probability made 2 days after the verdict. Supporting hypotheses, the tendency to recall a higher chance of conviction after the verdict was strongest among those who initially perceived acquittal to be least likely. Contrary to predictions, however, the perceived probability of acquittal did not significantly increase until 1 week after the verdict. Estimates of the prior likelihood of violence following a guilty verdict also increased immediately after the verdict and remained high 1 week later. Results are discussed in terms of the influence of mass media and cognitive processes on the development of hindsight bias over time.