This book describes years of research on behavior motivation conducted to provide a deeper understanding of the personality of the Soviet adolescent. The studies experimentally explore the motive hierarchy, the relationships among motives that directly stimulate behavior, conscious goals, decisions and intentions. The system of stably dominant motives is termed personality orientation. The series of experiments reported here were designed to determine which of three motive categories (or combinations thereof) was most powerful for each of the adolescent subjects. The three categories are concern for personal well-being, concern for the well-being of the collective, and intrinsic interest in the activity itself. A special experimental methodology was designed to allow judging of the relative strengths of the motives under study, to determine the level of voluntariness, and to identify those motives dominant at the level of direct needs and those on the level of conscious decisions. Other procedures such as systematic observation complement the experimental findings. In addition to details on the methodological design and results, case studies are provided in order to illustrate the motivational patterns identified experimentally. (Author/SJL)