© Oxford University Press, 2014. All Rights Reserved. The chapter aims at bringing more complexity to the body of literature on social categorization that underlies group conflict. Much of the literature tends to conceive of identities as dichotomous, e.g., Catholic and Protestant, thus perpetuating social divisions and intra-group hostility. In contrast, the authors argue for the introduction of multiple dimensions of social categorization for understanding group conflicts. The empirical studies show that whilst there is a high degree of overlap between religious and national identification in Northern Ireland, a significant minority of people crosscategorize. They endorse an unexpected combination of national and religious identities, such as Catholic-British or Protestant-Irish identity. The chapter concludes that to disregard the complexity of social identity and the existence of unexpected patterns of identification will run the risk of reinforcing negative intergroup evaluations.