The present research investigates the interrelation between two widely studied dimensions of social group identity—in‐group affect and centrality. Specifically, we test the validity of a quadratic curvilinear relation between in‐group affect and identity centrality. We propose that group members who feel either decidedly positive affect or decidedly negative affect towards their group are more likely to feel that their identity is a central component of their self‐concept relative to group members with neutral affect. We find evidence for a quadratic relation between in‐group affect and identity centrality with respect to people's cultural identity (N = 512), ethnic identity (N = 462), religious identity (N = 61, N = 384) and racial identity (N = 3600, N = 2400). Theoretical and practical implications for the measurement and conceptualization of group identification are discussed. Copyright © 2016 John Wiley & Sons, Ltd.