I met Erik Erikson on a couple of occasions, and was an admirer of the man. A lovely, sweet, gentle, dignified guy. Apparently, some think his work is obsolete. I think Young Man Luther, about Martin Luther, is wonderful work even if I don't agree with most if not all of his premisses.
His outlining of the typical "stages" of life, with their typical conflicts, holds up very well. The psychological capacity to handle the challenges that life presents is the key to relative satisfaction in life (the links in the quote box don't work):
1. Basic trust v. Mistrust. Birth to 1 year. From warm, responsive care infants gain trust or confidence that the world is good.
2. Autonomy v. Shame and Doubt. 1-3 years. Children start to use new mental and motor skills, and want to choose for themselves. Autonomy is created when the parents alow reasonable freedom and don't force or shame the child.
3. Initiative v. Guilt. 3-6 years. Children use play to experiment with what kind of person they might become. If the parent demand too much self-control the child might become insecure with who they are.
4. Industry v. Inferiority. 6-11 years. Children learn to work and cooperate with others. Negative experiences may lead to feelings of incompetence and inferiority.
5. Identity v. Identity diffusion. Adolescence. The adolescence tries to discover 'Who am I, and what is my place in society?' The resolution (or not) of this will result in your views on your future adult roles.
6. Intimacy v. Isolation. Young adulthood. Young people work on establishing intimate ties with others. Because of early disappointments an individual may not be able to form lasting relationships.
7. Generativity v. Stagnation. Middle adulthood. Generativity means giving to the next generation through work, children, or caring for other people. Failing to do this can make you feel that your life is meaningless.
8. Ego integrity v. Despair. Old age. In this final stage, people reflect on what type of life they led. If they are not happy with their life, they feel despair and fear death overmuch.
Like all stage theories, his is just a rough guide based on a lifetime of talking with people. "Typical" does not mean "right," and everybody struggles, at least at times, to do life.
Erikson's work fits in well with that of George Vaillant, whose life work has been studying the way people cope with life. Good solid stuff.