Erik Erikson proposed 8 stages of psychosocial development across the lifespan. The stages involve developing trust vs mistrust as an infant, autonomy vs shame and doubt as a toddler, initiative vs guilt in early childhood, 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. Successful completion of each stage leads to a healthy personality and the ability to move on to the next stage of development.