Social identity has been at the heart of European experimental social psychology for the past 25 years, and has been of growing interest in North America during the past decade where research in the field has expanded significantly. This text fills the need for an overview of recent developments in social identity theory, covering both theoretical and empirical work.

Naomi Ellemers has a PhD from the University of Groningen and is currently a Full Professor in social and organizational psychology at Leiden University, the Netherlands. Her research focuses on group processes and intergroup relations, and their effects on social behaviour in organizations. Dr. Ellemers has published extensively on this topic, for which she received several substantial research grants.