In the late twentieth and early twenty-first centuries, theoretical ideas about the personality of deviant and delinquent teenagers reached a new level. Methods, models and explanatory schemes of stress psychology, family psychology, pathopsychology, mental trauma, hereditary and personality deformations penetrated legal psychology along with traditional methods of age, differential, pedagogical and social psychology, in the context of which specialists tried to create universal, internally consistent theories of juvenile delinquency. However, all known attempts led to another more or less realistic private theory or approach, usually leaving unanswered questions concerning time, meaning and meaninglessness, spirituality and immorality of society, loneliness and alienation of a person. Simple explanations of the causes of crime and effective measures to combat it have been and continue to be offered. Psychological science currently demonstrates an obvious inability to answer, at least, the basic methodological questions of the personality development of adolescents. A 15-year-old teenager with a tendency to criminal behavior is likely to be the most difficult object of cognition. Internal inconsistency, ambivalence of the adolescent’s attitudes, reactions and behavior make us to pay attention to the study of his consciousness and self-consciousness, the evolution of thinking, mechanisms of reflection, the history of the life line formation again. In this context, we are developing the concept of “self-state” of a teenager personality, which goes back to the ideas of L.S. Vygotsky, as well as numerous studies by domestic and foreign authors. The main objective of this article is to substantiate the concept of “adolescent personality self-state”, its validation and operationalization. As there is virtually no such concept in psychology, the validation process will consist in substantiating the basic sources and mechanisms of its emergence, as well as in reflecting those qualities of personality that are denoted by the concept of “personality self-state”.