Erik Erikson proposed an 8 stage theory of psychosocial development from infancy to late adulthood. Each stage is characterized by a psychosocial crisis where the individual must balance competing psychological needs. Successful resolution of each crisis results in a healthy personality and ability to move to the next stage, while failure can negatively impact development. The stages involve developing trust, autonomy, initiative, competence, identity, intimacy, generativity, and integrity.