The Coevolution of Behavior and Beliefs: From Social Dilemmas to Pluralistic Ignorance

I will argue that human behavior cannot be understood from material incentives alone, as it is also shaped by internalized norms, cognitive processes, and beliefs about what others do and approve of. Yet these forces are typically studied in separate traditions. In the first part I introduce a general, testable framework that integrates material, social, and cognitive determinants of behavior in a single dynamic model, tracking the coevolution of actions, private attitudes, and beliefs about others, and supported by behavioral experiments across different settings and populations. The second part illustrates this approach through the case of pluralistic ignorance, focusing on how societies can systematically misread themselves because private attitudes and beliefs about others often change at different speeds. The framework shows that pluralistic ignorance can arise even without silence or deception, due to lags in belief updating, and that its dynamics depend on cultural context. In particular, change is faster but more volatile in loose cultures, and slower but more persistent in tight cultures, helping explain hidden majorities, delayed tipping points, and cultural mismatch. More broadly, the talk demonstrates how a unified formal framework can connect economics, evolutionary thinking, and social psychology in the study of social change.