This paper discusses the processes of mutual adaptation by ethnic groups in modern multi-ethnic societies. It focuses on relations between minorities and the dominant group. Various theories regarding these relations, including a definition of ethnic groups, are reviewed and a synthesis is advanced. This theory is based on a conflict model of society and considers the roles of coercion, differentiation, conflict, cultural patterns, and social structures in the adaptive processes of ethnic groups. The problem of overlapping or intersecting economic, political and cultural contradictions is analyzed. It is hypothesized that these contradictions will force certain changes in the way a majority treats minority groups, that these changes are connected with changes in the economic and political status of an ethnic group, and that the improvement of a minority group's situation will enlarge its common ground with the dominant group. (Author/AP)