The complex mosaic of cultural and racial heterogeneity in America throughout the twentieth century has given rise to various sociological perspectives to interpret the evolving interaction patterns and to give clues to the direction that policy decisions should take. The major theoretical frames of reference have been assimilation and cultural pluralism. The former has usually implied Anglo conformity, with the desired goal of integration of minorities into the mainstream. The latter has stressed the desirability of somewhat separatist social institutions and the retention of cultural identity by minority groups, usually with continued use of the native language (except for blacks) at least within the context of primary group interaction. Either of these processes can lead a minority group member to a socio-psychological state termed marginality. Within the assimilation model, even if Anglo conformity is accomplished, social distance still maintained by members of the dominant group may interfere with the deep, intense communication necessary to give a minority member access to primary groups and a sense of belonging. Within the cultural pluralism model, bilingualism may set up impediments to fluency in either language; further, the problem of meaningful communication with members of the dominant group may be exacerbated. (Author)