This approach is now known as social cognition , and its infl uence has moved far beyond the initial emphasis on person perception, pervading research on topics in intrapersonal, interpersonal, intragroup, and intergroup psychology and behavior. David L. Hamilton was one of the leaders and strongest advocates of the incipient revolution, and no one’s scientifi c contributions better refl ect the promise of theoretical integration offered by the social cognitive approach. This book honors those contributions by showcasing a small sampling of the many scientists and research programs that have been profoundly infl uenced by Dave’s work.