The first volume in this innovative two-volume set provides a comprehensive exploration of the major developments of social psychological theories that have taken place over the past half century, culminating in a state of the art overview of the primary theories and models that have been developed in this vast and fascinating field. Volume One covers Biological/Evolutionary Level of Analysis, Cognitive Level of Analysis, Content Model and Motivational and Affective Level of Analysis. Authored by leading international experts, each chapter represents a personal and historical narrative of the theory's development including the inspirations, critical junctures, and problem-solving efforts that effected theoretical choices and determined the theory's impact and its evolution. Unique to this handbook, these narratives provide a rich background for understanding how theories are created, nurtured, and shaped over time, and examining their unique contribution to the field as a whole. To examine its societal impact, each theory is evaluated in terms of its applicability to better understanding and solving critical social issues and problems. The Handbook of Theories of Social Psychology, Volume One is an essential resource for researchers and students of social psychology and related disciplines.