A developmental model is proposed in which the development of peer relations is conceived as a developmental task among other tasks. Continuity of the dimensions of cooperation and dominance in peer relations was assessed from the age of 12 months into the elementary school years and adolescence. As early as 12–24 months, some stability of both dimensions existed. Development of peer relations is anteceded and influenced by two accomplishments of mother-child relations – the capacity to use the mother as a secure base for social exploration and the responsiveness of the mother. In later years, the role of the mother in peer relations is augmented by relations with other primary referents (e.g., teacher and friends) and by the development of a self-concept. In late childhood and adolescence, peer competence is differentially related to self-descriptions and child-descriptions by primary referents. The stability and interrelatedness of self- and child-descriptions by primary referents are reciprocally related to adaptation in peer competence.