From Irrational Crowds to Collective Identity

Building on the critique of classical crowd psychology, this chapter introduces the Social Identity Model (SIM) as a transformative alternative to deindividuation theory. Where classical accounts cast crowds as irrational and chaotic, SIM shows that collective behaviour is meaningful, structured, and norm-governed through shared social identities. Developed by Stephen Reicher, SIM emerged from his analysis of the 1980 St Paul’s riot, which demonstrated that violence was selective, coherent, and ideologically driven – challenging the idea that crowds lose rationality. This chapter situates SIM within the intellectual revolution of European social psychology, rooted in Henri Tajfel’s Social Identity Theory and John Turner’s Self-Categorisation Theory, which reframed groups as fundamental units of analysis. It also examines the Social Identity Model of Deindividuation Effects, which shows that anonymity does not dissolve identity but amplifies group norms, enabling resistance in contexts of power imbalance. SIM thus replaces outdated views of crowds with an empirically grounded framework that highlights internal norms, prototypical leadership, and intergroup dynamics. It concludes by showing how these insights laid the foundations for the Elaborated Social Identity Model, which incorporates police–crowd interaction and forms the focus of the next chapter.