This collection of chapters, some new and most previously published in the American Psychologist, conveys the reciprocal importance of public policy formation and psychology. Many of psychology's leading researchers, clinicians, and policymakers - including psychologists active in the development of public policy and the coordination of advocacy efforts for the discipline's betterment - are brought together in this volume. These selections will provide readers with a greater understanding of policy evolution and deeper insights into the ways in which the discipline's involvement in public policy formation can enhance psychology's public standing and promote public support of the field.