The article discusses the integration-fragmenting role of ethnic diversity in the development of Russian society (the post-Soviet period). As a theoretical model for research we propose the wave model of a dynamic process that explains its development in the logic of the alternation of two phases of one cycle, which is started by the introduction and then is accompanied by the subsequent distribution of a socio-cultural innovation. The article concludes that the processes of ethnic convergence and segregation are part of social and cultural transformation of society.