Erik Erikson developed eight stages of psychosocial development across the lifespan. Each stage is characterized by a psychosocial crisis that must be resolved. If unresolved, it can negatively impact future development. The stages include trust vs. mistrust in infancy, autonomy vs. shame and doubt in early childhood, initiative vs. guilt in preschool, industry vs. inferiority in middle childhood, identity vs. role confusion in adolescence, intimacy vs. isolation in young adulthood, generativity vs. stagnation in middle adulthood, and integrity vs. despair in late adulthood. Erikson made major contributions to understanding development but his theory also faces some criticisms around conceptual clarity and generalizability.