Jury priors and observable defendant characteristics

Although prohibited, jurors sometimes condition, consciously or subconsciously, their belief that a defendant is guilty on the defendant’s race or ethnicity or other observable characteristics. This can be viewed as a juror forming a prior or pre-trial/evidence disclosure belief of guilt. In doing this, they rely on their perceptions of education, socio-economic status, religion, beliefs, networks, etc. for the defendant’s race (or other observable characteristic) and how they perceive those to influence the probability the defendant is guilty. This is consistent with aversive discrimination, which suggests that people want to be egalitarian and not condition on race but have a tendency to base decisions on factors that are discriminatory when race is not salient. When this prior or pre-trial/evidence disclosure belief of guilt overestimates the prior probability of guilt for those in the minority group, it underestimates the prior probability of guilt for those in the majority group. Prohibiting conditioning on observable defendant characteristics can be viewed as requiring the use of the population prior/pre-trial probability of guilt. Conditions for when such prohibition improves accuracy are provided. While it is difficult to effectively prohibit this, studies of aversive discrimination suggest that making race salient in a trial can reduce implicit bias on race. So these results may provide some guidance on when such activity should be permitted.