Introduction There is no consensus as to what the term successful aging means. A number of behavioral scientists operationalize the definition in terms of indicators of successful aging, such as life satisfaction (Butt & Beiser, 1987; Rudinger & Thomae, this volume) or development-related control beliefs (Brandtstädter & Baltes-Götz, this volume). Others have proposed models or strategies for aging “successfully” (e.g., Baltes & Baltes, this volume; Featherman, this volume), whereas biomedical researchers have addressed the effects of “successful” or “optimal” aging on life expectancy and morbidity (Fries, this volume). The distinction between successful and usual aging propposed by Rowe and Kahn (1987) highlights the consequences of the interaction between extrinsic and intrinsic factors in aging. Regardless of one's theoretical orientation or preference of definitions, the term successful aging serves as a useful heuristic device for stimulating research and discussion. Many approaches to successful aging are compatible with a developmental behavioral genetic perspective, especially in the extent to which they emphasize variation and plasticity. Furthermore, they point out interesting phenotypes or phenomena for study. Because the role of intrinsic and extrinsic factors presented in the definition by Rowe and Kahn directly addresses a primary concern of behavioral genetics (i.e., etiology of individual differences) we have chosen to emphasize their orientation to the topic in the introduction to this chapter. Examples from other perspectives on successful aging will be included in the remaining sections. Our intention is to present a general discussion of the interface between behavioral genetics and successful aging.