Erikson's stages of psychosocial development describes eight developmental stages through which a healthily developing human should pass from infancy to late adulthood.
In each stage the person confronts, and hopefully masters, new challenges.
Each stage builds on the successful completion of earlier stages.
The challenges of stages not successfully completed may be expected to reappear as problems in the future.
Erik Erikson developed the theory in the 1950's as an improvement on Freud's psychosexual stages.
Erikson accepted many of Freud's theories (including the id, ego, and superego, and Freud's infantile sexuality represented in psychosexual development), but rejected Freud's attempt to describe personality solely on the basis of sexuality.
In his most influential work, Childhood and Society (1950), he divided the human life cycle into eight psychosocial stages of development.