Initially differentiating ideas of self-concept, personality, and self-esteem, this paper discusses the development of the self from infancy through adolescence. The discussion of infancy focuses on learning about bodily self and related disruptions and describes the emergence of the social and independent self. The discussion of toddlers and preschool children deals with having separate thoughts, concepts of "me" and "mine," skill development and temper tantrums, comparisons, games and time, the looking-glass self, interest and security, identification with parents, and behavior and health problems. School-age children are discussed in relationship to teachers, playmates, the concrete self, autonomy, depression and poor self-esteem, and behavior problems and common illnesses. With regard to adolescence, the document explores the role of abstract thought, self-consciousness, popularity neuroses, overdifferentiation, intellectualization, asceticism, depression, physical appearance, identity, unemployment, symptoms of disruption in self-concept development, hypochondriasis, and anorexia nervosa. (RH)