Date of Award


Document Type

Campus Access Dissertation



First Advisor

Brent Simpson


This research seeks to address a question receiving little prior attention in the social identity literature: how can groups effectively increase social identification among group members? Given the strong and positive relationship between identification and cooperation found in prior work, understanding the factors that increase social identity are important for cultivating successful solutions to collective action problems. In this dissertation I argue that one explanation for how groups can increase social identification is through norms, or expectations for group-related behavior. Social identity is generated among norm conformers through increasing perceptions of similarity - a necessary and sufficient precondition for identification. Based on this reasoning I suggest that members of groups with strong behavioral norms have higher levels of identification compared to individuals in groups with weak or no norms. I also predict that this effect holds regardless of whether norms prescribe relative selfishness or generosity. Following prior work, I also hypothesize that cooperation levels will be higher in normative versus non-normative groups due to higher social identity levels. The research consists of two public goods experiments. The first experiment examines the relationships between norms, social identity, and cooperation in a collective action situation. Results show that, consistent with my theory, normative group members report more social identity compared to non-normative group members. Further, findings indicate that norms have their effect on social identity regardless of whether they prescribe selfishness or generosity (i.e. as long as norms are present, social identity is increased). Inconsistent with much prior work, however, increased social identity levels do not produce higher rates of cooperation. To address this inconsistency, a second experiment explores the relationship between social values (i.e. preferences for how outcomes are distributed between self and others) and norm conformity on social identity and cooperation. Results from the second study suggest that social identity stemming from norms motivates individuals to put aside personal preferences in order to conform to group expectations. This effect is considerably stronger for prosocials compared to proselfs. Taken together, these studies provide a better understanding of how norms influence social identity and cooperation in collective action groups.


© 2009, Kyle Irwin