Erik Erikson, in 1982, completed his theory about the social development of people from birth to old age. His earlier work on social development helped shape the field of sociology. His theory outlined eight specific stages of social development he theorized are present in every healthy, sane human being. Erikson identified many of the deep sociological influences shaping who a person becomes and the psychological influences that affect these changes.

Stages 1 and 2

Stage 1, from birth to 1, is the basic trust stage where a child learns to have faith in her parents. Erikson identified this stage as the "hope" stage. If parents are unreliable during this stage, a child can have difficulties advancing to the next stage. Stage 2, from 1 to 3, is the period where a child transitions away from her parents and begins to understand the world. Erikson identified this stage as the "will" stage. If parents neglect their child during this stage or smother her, she may have problems advancing to the next stage.

Stages 3 and 4

Stage 3, from 3 to 6, is the initiative stage, where a child begins making decisions on her own. Erikson called this stage the "purpose" stage. If others try to restrict the child's initiative, she may lash out against them. Stage 4, from 6 to 11, is the stage where a child begins developing her sense of self-worth. Erikson called this stage the "competence" stage. A child in this stage begins noticing the differences between herself and others. She may need help coping with feelings of inferiority during this stage.

Stages 5 and 6

Stage 5, from age 11 to mid-20s, is the identity creation stage, where a child begins to form her own identity and is exposed to roles. Erikson referred to this stage as the "fidelity" stage. If others try to force the child into specific roles, she can face confusion about her identity. Stage 6, from mid-twenties to early 40s, is the relationship stage, where an individual dates, forms relationships and falls in love. Erikson referred to this stage as the "love" stage. Individuals have trouble leaving this stage if they avoid settling down or have trouble forming relationships.

Stages 7 and 8

Stage 7, from early 40s to mid-60s, is the reflection stage, where an individual considers his life and how much he has accomplished. Erikson called this stage the "caring" stage. The individual may have difficulties if she begins facing stagnation: the feeling she has not done enough in life. Stage 8, from mid-60s to old age, is the final stage, where the individual begins facing the end of her life. Erikson called this stage the "wisdom" stage. A person may face severe despair during this stage if she is uncomfortable with her life.