Psychol Sci. 2018 Nov 12:956797618805750. doi: 10.1177/0956797618805750. [Epub ahead of print]

People Make the Same Bayesian Judgment They Criticize in Others.

Cao J1, Kleiman-Weiner M1,2, Banaji MR1.

Author information

1

1 Department of Psychology, Harvard University.

2

2 Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology.

Abstract

When two individuals from different social groups exhibit identical behavior, egalitarian codes of conduct call for equal judgments of both individuals. However, this moral imperative is at odds with the statistical imperative to consider priors based on group membership. Insofar as these priors differ, Bayesian rationality calls for unequal judgments of both individuals. We show that participants criticized the morality and intellect of someone else who made a Bayesian judgment, shared less money with this person, and incurred financial costs to punish this person. However, participants made unequal judgments as a Bayesian statistician would, thereby rendering the same judgment that they found repugnant when offered by someone else. This inconsistency, which can be reconciled by differences in which base rate is attended to, suggests that participants use group membership in a way that reflects the savvy of a Bayesian and the disrepute of someone they consider to be a bigot.