The problem of socialization of the younger generation in general and the development of assertiveness of the individual as a subject of communication, in particular, becomes especially relevant against the background of radical changes in social, political and economic life. The immaturity of the individual's ability to set and implement their own goals and aspirations leads to dissatisfaction with life, the emergence of social fear. Considering the development of assertiveness in neuropsychology, the emphasis is on working with the behavioral and motivational-value range of the individual, which indicates the difficulty of differentiating manifestations of self-confidence and aggressiveness. For the development of confident personality behavior, numerous psychological programs of active social psychological training offer trainings. The purpose is to theoretically identify and empirically investigate the neuropsychological features of the development of assertiveness of adolescents in a children's health institution and secondary school, diagnose neuropsychological factors and present the most pronounced individual psychological qualities of adolescents, which should be identified as psychological reasons that determine the development of assertiveness in adolescence. At different stages of the empirical study, a number of psychodiagnostic techniques were used: the questionnaire "Diagnosis of the assertiveness level"; methods of diagnostics of basic values; SOINT questionnaire; associative experiment with the following procedure of subjective scaling; colour test of relations, test-questionnaire "Emotional orientation"; level of subjective control; personal questionnaire of R. Kettell.