Complex adaptive systems in the behavioral and social sciences.

This article examines applications of complexity theory within the behavioral and social sciences. Specific attention is given to the fundamental characteristics of complex adaptive systems (CAS)—such as individuals, groups, and societies—including the underlying structure of CAS, the internal dynamics of evolving CAS, and how CAS respond to their environment. Examples drawn from psychology, sociology, economics, and political science include attitude formation, majority–minority relations, social networks, family systems, psychotherapy, norm formation, organizational development, coalition formation, economic instabilities, urban development, the electoral process, political transitions, international relations, social movements, drug policy, and criminal behavior. The discussion also addresses the obstacles to implementing the CAS perspective in the behavioral and social sciences and implications for research methodology.