In general the sociocultural process in which the sense and consciousness of association with one national and cultural group changes to identification with another such group, so that the merged individual or group may partially or totally lose its original national identity. Assimilation can occur and not only on the unconscious level in primitive societies. It has been shown that even these societies have sometimes developed specific mechanisms to facilitate assimilation, e.g., adoption; mobilization, and absorption into the tribal fighting force; exogamic marriage; the client relationship between the tribal protector and members of another tribe. In more developed societies, where a stronger sense of cultural and historical identification has evolved, the mechanisms, as well as the automatic media of assimilation, become more complicated. The reaction of the assimilator group to the penetration of the assimilated increasingly enters the picture.
Various factors may combine to advance or hinder the assimilation process. Those actively contributing include the position of economic strength held by a group; the political advantages to be gained from adhesion or separation; acknowledged cultural superiority; changes in religious outlook and customs; the disintegration of one group living within another more cohesive group; the development of an "open society" by either group. Added to these are external factors, such as changes in the demographic pattern (mainly migration) or those wrought by revolution and revolutionary attitudes. Sociologists have described the man in process of assimilation as "the marginal man," both attracted and repelled by the social and cultural spheres in which he lives in a state of transition.
