In order to determine the contribution of social pluralism (ethnic, religious, and racial differences) to violence, diverse multivariate cross-national analyses were done. These involved 109 variables on conflict and violence; pluralism; and social political, economic, demographic, and cultural differences for all states, 1932 to 1982. The results show that pluralism is a multidimensional empirical concept; that regardless of which dimension is focused upon, it has a lesser relationship to violence than do other national characteristics, such as political freedom. And what relationship is found between pluralism and violence, holding other variables constant, is largely accounted for by the number of ethnic and religious groups in a state. Drawing on this and other studies, the conclusion is that where political power is centralized around a trans-plural group, such as a military junta or monarch, or trans-plural ideology, such as communism or fascism, then violence is highly likely, regardless of what plural units may or may not exist. And where power is centralized, nondemocratic, and highly dependent upon one's social group membership, such as ethnicity or religion, then collective violence is also highly likely.