An Exploratory Center for Health Behavior Research with Children and Adolescents at the University of Michigan is proposed. The Center will support an Administrative and Planning Core with a Data Acquisition, Analysis and Management Unit and a Biobehavioral Measurement Unit as well as multidisciplinary pilot studies. The common focus of the pilot studies consistent with the long-term objectives of the Center is to generate knowledge concerning antecedent and consequent factors influencing the development and continuation of risk-taking and health-promoting behaviors and the developmental course of these behaviors among children and adolescents from different racial and socioeconomic backgrounds. This knowledge will be used as a basis for designing and testing the efficacy of interventions to reduce risky behaviors and promote healthy behaviors with the goal of improving health throughout the lifespan. The development of theories through iterative testing will inform the preventive and health promotive care for vulnerable youth. The initial proposed research projects focus on factors influencing alcohol use, early sexual activity, and exercise and the underlying biobehavioral mechanisms by which these factors exert their effects. The pilot studies will provide data necessary to justify extramural funding for continuing research efforts in these areas of investigation. In addition, other pilot studies will be funded consistent with the aims of the Center. The proposed Center will establish a targeted investigative initiative that can serve as a role model of scientific excellence in augmenting both the pace and the scientific depth of behavioral and biological research focused on prevention and health promotion among children and adolescents.