Erik Erikson's theory views maturity as proceeding through eight stages that are both psychosocial in nature and genetically determined:

1. Trust vs. Mistrust: Lasting from birth to about age 18 months, this stage provides the infant a basic sense of safety (adequate resolution) vs. insecurity and anxiety (inadequate resolution).

2. Autonomy vs. Self-Doubt: The time from about 18 months to three years is marked by the unfolding of a self-view as capable of bodily control and the ability to make things happen (adequate resolution) vs. the feeling of inability to control events (inadequate resolution).

3. Initiative vs. Guilt: Between the ages of three and six, the child develops confidence as an initiator and creator (adequate resolution) vs. lack of self-worth (inadequate resolution).

4. Competence vs. Inferiority: The period between six years and puberty is the time to develop adequacy in basic social and intellectual skills (adequate resolution) vs. feelings of failure and lack of self-confidence (inadequate resolution).

5. Identity vs. Role Confusion: During the adolescent years, a comfortable sense of self as a person is reached (adequate resolution) vs. a fragmented, shifting, or unclear sense of self (inadequate resolution).

6. Intimacy vs. Isolation: Early adulthood is distinguished by development of the capacity for closeness and commitment to another (adequate resolution) vs. feelings of aloneness and separation or denial of need for closeness (inadequate resolution).

7. Generativity vs. Stagnation: The middle adult years are marked by focused concern beyond oneself to family, society, and future generations (adequate resolution) vs. self-indulgent concerns and a lack of orientation toward future (inadequate resolution).

8. Ego Integrity vs. Despair: By the later adult years, a sense of wholeness and basic satisfaction with life is seen (adequate resolution) vs. feelings of futility and disappointment (inadequate resolution).