Although moral judgments often emerge from social interactions (e.g., ethic committees), past research rarely addressed two fundamental questions: 1.) Do individual moral judgements differ from collective judgments (i.e., moral judgments made by groups)? 2.) Does making moral judgments collectively change subsequent individual moral judgments?
In two preregistered study, we investigated these questions. Participants judged ten moral dilemmas. Specifically, they judged two choice options (deontological vs. utilitarian option) concerning two dimensions, namely the moral acceptability and the moral requiredness of each option. First, participants judged the dilemmas individually, then, in groups, and, finally, individually again. We tested two competing hypotheses. Past research suggests that collective judgments are more utilitarian than individual judgments (a phase × option – interaction; Hypothesis 1a). Specifically, participants' preference for the utilitarian (deontological) option will increase (decrease) from the first individual phase to the collective phase. However, past research also allows for the hypothesis that groups will agree on the least common denominator among members (a phase × dimension – interaction, Hypothesis 1b). Specifically, the acceptability (requiredness) of both options will increase (decrease) from the first individual phase to the collective phase. Our results reveal evidence against Hypothesis 1a and in support of Hypothesis 1b. Furthermore, our results show that collective moral judgments tend to polarize towards the majority opinion within the group and that collective moral judgments change subsequent individual moral judgments.