What kind of person is a thirty-year-old?

In this article we review the thirty-year-old person from the viewpoint of the development psychology, life span, physical health and family life. In his psychological development a person has at this stage become adult, but he still uses some psychic mechanisms and coping strategies which are typical for the adolescent. Intrapsychic world, the working role and the family life are stabilizing, but the changing over to the independence and working life can be more difficult today than earlier. Although with most people the adult life has settled down and physical and psychiatric illnesses are relatively rare, part of the thirty-year-olds are not independent, placed to the working life or are not healthy. In the following paper, main theories or findings in psychological and family life development and mental health of a thirty-year-old person are presented.