Focusing attention on a multiplicity of issues surrounding the study of behavior is timely and important. Some scholars believe that, across various sub-disciplines of the field, social psychology actually has contributed a great deal to our understanding of behavior and its antecedents. From this perspective, there is considerable utility in drawing together such work in one place. Other scholars suggest that, though there has been great progress elucidating the internal cognitive, affective and motivational underpinnings of behavior, much less research focuses on external behavior itself. From this perspective, it is important to identify the theoretical gaps, the empirical needs, and the focal issues that still demand attention. Chapters in this timely volume review some of these key issues, with contributions from some of the world's leading social and personality psychologists.