From Cicero to Cohen: developmental theories of aging, from antiquity to the present.

Cicero's famous essay "On Old Age," written in ancient Rome, was one of the first detailed depictions of the challenges and opportunities posed by the aging process. Several modern developmental theories of the life cycle have echoed many of the themes of Cicero, including the existence of unfolding life stages with specific tasks and transitions. Freud's psychoanalytic theory of infantile sexuality provided a limited starting point, as well as a theoretical base for Erik Erikson's proposed eight stages of the life cycle. Unlike Freud, however, Erikson and others including Daniel Levinson, George Vaillant, and Carol Gilligan elaborated on forces in adult development that were distinct from early life experiences. Gene Cohen's theory of human potential phases took middle age as a starting point and proposed an extensive structure for late-life development based on emergent strengths including wisdom and creativity.