PROJECT SUMMARY Hostile marital conflict and harsh parenting (family aggression) are highly prevalent. Chronic exposure to family aggression elevates individuals’ risk for antisocial and risky behavior, depressed mood, and cognitive decrements. Significant gaps in this research include scarce investigations of long-term developmental trajectories of adaptation and maladaptation associated with exposure to family aggression. Furthermore, explaining variability in trajectories of health in the context of family aggression—why some individuals exhibit resilience and others deteriorate—is a critical need for science and practice. The proposed study addresses these open questions and will illuminate autonomic nervous system activity and sleep regulation parameters (bioregulatory processes), as well as social context variables (socioeconomic status), which may mediate the risk of family aggression or operate to exacerbate or protect against its effects on emotional and behavioral maladjustment from childhood through early adulthood. The design builds on a well-characterized 6-wave study and involves 2 additional waves. The sample consists of youth between 8 and 18 years across the six study waves who will be ~22-23 years at the seventh wave. Strengths of the design include the large and diverse sample, high retention rates, breadth of measurement across important outcome domains, and 8 study waves, permitting analyses of long-term trajectories of mental health, substance use, and cognitive functioning. Constructs are assessed with well-validated measures and procedures. The study will advance understanding of the long-term effects of family aggression; elucidate bioregulatory processes that transmit risk or function as vulnerability or protective factors in the context of family aggression; and document young adult outcomes of family aggression in domains of public health priority, such as substance use and mental health (Healthy People 2020). The diverse community sample allows tests of research questions across a wide range of socioeconomic status. Results will help identify youth at greatest risk for negative mental and behavioral health outcomes in early adulthood and identify family and bioregulatory targets for prevention and intervention.