On the other hand, there was a constant tension between the persistence of immigrant customs brought into a town and the integrative mechanisms enabling newcomers to be accepted. Intermarriage with partners of different origins, economic success, and opportunities to live away from immigrant areas all contributed to the dilution of specific immigrant cultures, particularly where there were comparatively few contrasts between the immigrants and the host community. New waves of postcolonial migration to European urban centers during the last third of the twentieth century replicated both patterns of integration and of segregation, with one important difference. The integrative mechanisms came to operate in two directions, enabling elements of immigrant culture, primarily music, dress, and food, to become accepted as part of mainstream urban culture.