The present article reports the results of cross-cultural research on the role of sociocultural factors that develop attitudes toward extremism in school students of Moscow, Russia, and Riga, Latvia. Equally, it analyzes various aspects of social activity of adolescents: their attitude to legislative sanctions against extremist activities, a tendency to express various ways of political protest, etc. Special attention is paid to the role of social and cultural factors that determine the specific features of adolescents’ attitude to extremism. We consider such factors as the degree of social distance from extremist organizations or membership of a national majority or minority, etc. The article reports on the relationship between adoption of extremist behaviour and attitudes of aggressive behaviour in various social situations, and in the situation of bullying in particular. In addition, the article presents the results of factor analysis to identify a set of features that determine not only those ones related to extremism, but also the position of the teenagers in the propensity for violence and aggressive behaviour as a way to solve their own conflicts. Also, based on the selected factors, the averaged profiles of teenagers in Moscow (Russia) and Riga (Latvia), who claimed their own relationship with extremist organizations, are shown. The main conclusions of the article can be briefly presented in the following points. In general, negative attitude towards extremism dominates in schoolchildren. It is expressed in personal non-acceptance of extremism. Social environment of teenager affects assessment of various kinds of extremist manifestations. The study revealed significant differences in attitudes toward extremism, depending on the membership of a national minority or titular nation.