As research in human development moves away from its strong emphasis on particular life stages, this timely special issue provides an interdisciplinary analysis of research in human development across the lifespan. The authors present varied and engaging topics, including a focus of biocultural and personal influences on development; the emergence of a stronger partnership between life-course sociology and life-span psychology; an historical framework for the frequently-controversial cohort differences in intelligence; evolutionary perspectives of aging of brain structure and cognition; and evolutionary biology and the strategic view of ontogeny. A notable contribution to the field of human development, Theoretical Approaches to Lifespan Development is a thought-provoking work for researchers, educators, policymakers, and practitioners.