descent, in anthropology, method of classifying individuals in terms of their various kinship connections. Matrilineal and patrilineal descent refer to the mother's or father's sib (or other group), respectively. Bilateral descent refers to descent derived from both sibs equally. Descent groups are of basic significance in the social structure of most nonindustrial societies. They constitute a series of social groups that dominate the domestic organization and the process of socialization, the use and transfer of property, the settlement of disputes, religious activities such as ancestor worship, and certain political relationships. Some lineage systems extend to the limits of the society itself. The Tiv of E Nigeria, for example, all consider themselves descendants in the male line of an eponymous ancestor, and the genealogy of this progeny defines the complete outline of descent group structure.