The effects of child sexual abuse have become a leading concern of mental health service providers. Despite an explosion of studies, one major difficulty in this research is the lack of a developmentally sensitive model for conceptualizing short- and long-term effects and continuity and discontinuity of effects over time. This article proposes a model based in the perspective of developmental psychopathology. It is argued that incest has its unique negative effects in the domains of self and social functioning, specifically in jeopardizing self-definition and integration, self-regulatory processes, and a sense of security and trust in relationships. Studies with clinical samples indicate that diagnostic conditions associated uniquely with a history of incest reflect serious self- and social impairments. A review of the developmental literature on self and social development summarizes each major developmental transition from infancy to middle adulthood, and the implications for the negative effects of incest on development are discussed. Finally, implications for developmentally sensitive research are discussed.