Do behavioral base rates impact associated moral judgments?

In a series of studies, we ask whether and to what extent the base rate of a behavior influences associated moral judgment. Previous research aimed at answering different but related questions are suggestive of such an effect. However, these other investigations involve injunctive norms and special reference groups which are inappropriate for an examination of the effects of base rates per se. Across five studies, we find that, when properly isolated, base rates do indeed influence moral judgment, but they do so with only very small effect sizes. In another study, we test the possibility that the very limited influence of base rates on moral judgment could be a result of a general phenomenon such as the fundamental attribution error, which is not specific to moral judgment. The results suggest that moral judgment may be uniquely resilient to the influence of base rates. In a final pair of studies, we test secondary hypotheses that injunctive norms and special reference groups would inflate any influence on moral judgments relative to base rates alone. The results supported those hypotheses.