In this volume leading behavioral scientists describe advances in our understanding of the multiple biopsychosocial regulatory processes underlying the development of children's behavior disorders. A full spectrum of regulatory influences is addressed, ranging from genes to cultural factors. Individual chapters highlight the importance of developing research paradigms that synthesize biological, behavioral, and social-ecological influences, and of viewing self-regulation as a complex system that reorganizes across development. The regulatory foundations of a diverse range of childhood behavior problems are examined, including anxiety, social withdrawal, depression, conduct problems, inattention and impulsivity, and sleep problems.