This paper discusses various theories of developmental psychology, and presents a developmental theory of socialization founded upon the following premises: (1) that a materialistic theory of development and socialization must incorporate not only ecological aspects but also underlying political/economic dynamics of the society in which and for which the theory is developed; (2) that a developmental theory of socialization must be dialectic in order to be relevant to all internal and external factors and contradictions of a given societal system; and (3) that in order to analyze the totality of adolescent behavior, the theory must encompass the whole prism of behavioral aspects. Behavior and action of adolescents must be viewed from at least three dimensions: association, dissociation, and disorientation. Different social classes of adolescents find expression in different tendencies of behavior and action. A pilot study of adolescents in Northern Germany is described. It concludes that the behavior and self-concepts, especially of working-class adolescents, are not adequately recognizable as long as the theories of psychological development include scientific biases toward this group. (Author/JLL)