摘要:The Last decades have witnessed elevated tension and conflicts in young people’s environment. There has been an increase in crime, terrorism, suicides, addictions, and other behavioral deviations among the young. Up to the 21st century, hostility was equated with aggression in its broad, non-differentiated sense. Today hostility is considered to be an inflexible and complex personality trait. Recent studies show that several genes can be viewed as genetic predictors of aggressiveness and hostility (Rodríguez-Ramos Á., Et al., 2019; Tkachenko O.N., 2016). The paper investigates the relationship between genotype and ethnicity as predisposing factors in manifesting hostile behavior. The study involved 320 participants - adolescents and young men of different ethnicity (Russians, Armenians, Dagestanis, Kabardians), aged from 12 to 19. Research methods: Buss-Durkee Hostility inventory (in the adaptation of Osnitsky A.K., 1998); isolation genomic DNA from buccal epithelial cells. Genotypes and alleles of the monoamine oxidase enzyme (MAOA) gene were considered as a candidate gene. Statistical analysis and data processing were performed using the PSPP 0.8 5. It was established that the low-active variant of the MAOA monoamine oxidase A gene (LPR) plays a significant role in determining the risk of hostile behavior. As far as the ethnic factor is concerned, low-level MAOA variants have significant differences in the populations of Russians compared with Dagestanis, or Kabardians. The results received contribute to understanding the relationships between genetics and behavior. It will help develop effective methods for the prevention of aggressive and hostile behavioral patterns.