Over the course of the last five decades, social identity theorizing has emerged as a major framework for understanding group processes and the psychology of group life (e.g., see Reicher, Spears, & Haslam, 2010; Turner, 1999). At its core, work in this tradition serves to explain how social behaviour is structured not merely by people’s sense of themselves as individuals (as ‘I’ and ‘me’) but also, and often more importantly, by their sense of themselves as members of social groups (as ‘us’ and ‘we’). This observation reflects a core insight of the social identity approach – namely that humans’ psychological make-up is largely a product of the fact that we live, and have evolved to live, in social groups. As a result, groups are not simply external features of the world that provide a backdrop for our behaviour. Rather, they structure our psychology through their capacity to be internalized as part of our sense of self. More particularly, they provide us with a sense of social identity: the “knowledge that [we] belong to certain social groups together with some emotional nd value significance to [us] of this group membership” (Tajfel, 1972, p. 292).