A biopsychosocial model of the development of chronic conduct problems in adolescence is presented, supported by empirical findings. The model posits that biological dispositions and sociocultural contexts place children at risk, but life experiences with parents, peers, and social institutions increment and mediate this risk. A transactional developmental model is best suited to describe the emergence of chronic antisocial behavior over time. Reciprocal influences among dispositions, contexts, and life experiences lead to recursive iterations that exacerbate or diminish antisocial development. Cognitive and emotional processes mediate the relationship between life experiences and conduct problem outcomes. The model integrates biological, sociocultural, and life experience factors, emphasizing nonlinear interactions and the role of social information processing. The model is supported by extensive research on genetic, hormonal, temperamental, family, peer, and social factors. It highlights the importance of early life experiences, such as parenting, peer relationships, and social institutions, in shaping conduct problems. The model also considers cultural and gender differences in risk factors and outcomes. The model suggests that multiple factors contribute to conduct-problem outcomes, with interactions between factors playing a critical role. The model emphasizes the need for integrated approaches to understanding and preventing conduct problems, as well as the importance of considering individual differences and contextual factors. The model is informed by a long legacy of theorists and is supported by empirical findings from various studies, including the Child Development Project. The model provides a comprehensive framework for understanding the development of chronic conduct problems and has implications for prevention and public policy.A biopsychosocial model of the development of chronic conduct problems in adolescence is presented, supported by empirical findings. The model posits that biological dispositions and sociocultural contexts place children at risk, but life experiences with parents, peers, and social institutions increment and mediate this risk. A transactional developmental model is best suited to describe the emergence of chronic antisocial behavior over time. Reciprocal influences among dispositions, contexts, and life experiences lead to recursive iterations that exacerbate or diminish antisocial development. Cognitive and emotional processes mediate the relationship between life experiences and conduct problem outcomes. The model integrates biological, sociocultural, and life experience factors, emphasizing nonlinear interactions and the role of social information processing. The model is supported by extensive research on genetic, hormonal, temperamental, family, peer, and social factors. It highlights the importance of early life experiences, such as parenting, peer relationships, and social institutions, in shaping conduct problems. The model also considers cultural and gender differences in risk factors and outcomes. The model suggests that multiple factors contribute to conduct-problem outcomes, with interactions between factors playing a critical role. The model emphasizes the need for integrated approaches to understanding and preventing conduct problems, as well as the importance of considering individual differences and contextual factors. The model is informed by a long legacy of theorists and is supported by empirical findings from various studies, including the Child Development Project. The model provides a comprehensive framework for understanding the development of chronic conduct problems and has implications for prevention and public policy.