The work is devoted to the study of the phenomenon of internality of high school and junior college students living in different regions of Russia. The study involved 486 teenagers from 15 to 18 years old (M = 16,6; 307 girls): 234 schoolchildren (grades 10–11) and 252 college students (1–2 courses). The data were obtained using the “Level of subjective control” method (modified by A. G. Gretsov). It is shown that, in general, the sample of students aged 15–18 is characterized by an indefinite locus of control. It reflects the process of formation of subjective control as a higher mental function, relevant for this age, in the form of a transition to the internal plan of external control by others. This process is the content of the stage of formation of a personal position of a teenager in the field of significant life events, planning actions and responsibility for their actions. Regardless of the choice of further educational route after completing the basic stage of general education, modern boys and girls are generally not ready to take responsibility for their professional choice. When determining the trajectory of professionalization, the vast majority of older adolescents rely on random and external circumstances beyond their control. According to the data obtained, the factor of the region of residence makes the greatest contribution to the formation of the internality of modern adolescents. A hypothesis has been put forward that more complex socio-economic and environmental living conditions contribute to earlier maturation and independence of adolescents.