1905 Sigmund Freud develops his theory of psychosexual development, claiming there are five stages through which a child progresses toward sexual maturity.
1930s Jean Piaget proposes a stage-based theory of cognitive development.
1980 Building on Erikson’s work, American psychologist James Marcia explores identity formation in adolescence.
1996 In her bestselling book New Passages, American writer Gail Sheehy notes that adults are prolonging their adolescence into their 30s, pushing back all of Erikson’s stages of adulthood by approximately ten years.
Erik Erikson understood human development in ...