Infancy, early childhood, preschooler, school age and adolescent are some of the stages in Erikson's theory of development. Others include young adult, middle-aged adult and older adult.
Infancy is characterized by feelings of optimism and trust in well-handled children, and mistrust in poorly nurtured children. Children in the early childhood stage learn new skills and gain self-esteem or feel ashamed, based on the quality of parenting. The preschooler stage is playful and children ape adult behavior. Children either broaden their skills and learn cooperation or become fearful and clingy.
The school age comes with formality in activities. The degree of success of previous stages determine whether a child learns more skills and becomes industrious or feels inferior. A child then goes on to achieve self-identity through experimentation in the adolescent stage. Feelings of self-doubt could also come up.
Young adults seek love and make commitments in long-term relationships with intention for marriage. Middle-aged adults are compelled to provide care, both to their spouses and children. A sense of self-fulfilment is achieved by the older adult; feelings of despair emerge when earlier stages left unresolved issues.