While previous research in experimental economics has established that individuals react to changes in the applicable social norms, the question to when individuals comply with social norms has been neglected. In this study, we examine how group identification affects compliance with identity-dependent social norms. In our online experiments, we manipulate group identification by varying the moral similarity between the subjects and an artificial social group, while keeping all other factors including the identity-dependent social norms fixed. Our experimental design allows us to test how moral similarity affects group identification and how group identification affects norm compliance in a decontextualized setting.
What determines whether someone complies with a social norm? The social identity approach offers a mechanism for norm compliance: a person who feels similar to a group identifies more with that group and, in turn, complies with the group's norms. We used an economics experiment to test this mechanism. We manipulated the similarity between an individual and a social group by exogenously changing their similarity in moral values. Moral values were identified using a survey developed in conjunction with moral foundations theory. In one treatment, the subject and social group's moral values were similar, and in another, they were dissimilar. Subsequently, we measured group identification and behavior. To measure behavior, we used a modified rule-following task in which the social group expressed a normative expectation that subjects follow "the rule". We found that moral similarity increased group identification, and group identification increased rule compliance. We show that this behavior change was due to increased group norm sensitivity rather than changes in the group norms. We advance the study of social identity by establishing a causal pathway between group identification and behavior change.