Jean Piaget Sensorimotor stage Assimilation Object permanence Preoperational stage Theory of mind Erik Erikson Concrete operational stage Formal operational stage Primary sex characteristics Secondary sex characteristics Biological sex Trust vs. mistrust Autonomy vs. shame and doubt Initiative vs. guilt Industry vs. inferiority Identity vs. role confusion Intimacy vs. isolation Generativity vs. stagnation Ego integrity vs. despair developmental psychology puberty adolescence schemata Egocentrism Conservation