Two widely cited approaches to personality development are those of Sigmund Freud and Erik Erikson.
Sigmund Freud's stages of psychosexual development. Sigmund Freud developed a treatment theory called psychoanalysis, which is based upon a theory of psychosexual stages of development (Table 1).

Erik Erikson's stages of development. Erik Erikson proposed a theory of development that continues throughout the life span. His theory states that there are universal life stages and that a specific psychosocial dilemma occurs at each phase of development. These problems (crises) must be resolved before an individual can move to the next developmental stage (Table .) . Erikson's theory has been credited for accounting for continuity and changes in personality development. It has also been criticized for vagueness and has not stimulated a great deal of empirical research.
