The article is devoted to an urgent problem, which from year to year acquires special importance and attention, without losing its relevance at all times of mankind, this is the education of adolescent behavior. In the research work, the authors revealed the manifestation of aggressiveness in modern adolescents, tried to study in depth the cause of its occurrence and the characteristics of its occurrence. Also emphasizing that aggressiveness has not only a significant impact on emotional development and well-being, personality formation, mental health of a person, but also reflected on the growth of child crime, which is becoming more acute due to various manifestations of aggressiveness, child subculture and cruelty in the family. During the first ascertaining experiment, an attempt was made to clarify the definition and reveal the essence of the concepts of "aggressiveness" and "aggression", based on the "Hand test" and "bas-Dark questionnaire" in order to determine the level of aggressiveness. The authors claim that the development of aggressiveness of a teenager is influenced by such natural features of temperament as excitability and the strength of emotions, which in turn provokes the formation of qualities such as irritability, nervousness, inability to behave. In conclusion, it is concluded that the root of the signs and properties of aggressiveness is dependence on difficulties in the environment and directly on the influence of shortcomings in the educational work of the family.