DUAL ORGANIZATION

a social structure characterized by the division of society into two complementary parts called moieties. According to a strict definition, moieties are groups that are exogamous (i.e., marriage between members of the same moiety is forbidden), of unilineal descent, and in some sense opposed. Sometimes the term moiety is used more loosely to refer simply to one of two divisions of a society, regardless of descent or marriage regulation. Dual organization, then, occurs in two basic forms: as a feature related to but not necessarily determining the regulation of marriage (kinship moieties) and as a ceremonial organization. Usually the two forms are combined, but sometimes only one form occurs, or the two appear concurrently as separate systems. Thus, the Canela of South America have four dual schemes, one of which regulates marriage whereas the other three are independent ceremonial groupings; all of these bisect the tribe exhaustively and determine membership by the name given a person by his maternal uncle, by the generation of his peer group, or by affiliation to one of the Canela social groups. Although moieties are often referred to interchangeably with phratries and clans, they are distinct from these two groupings. Phratries comprise two or more related clans, and there must be more than two phratries in the society. Clan members emphasize descent from a common ancestor, whereas members of a moiety, while regarding themselves as related, do not stress common descent. Clans function frequently as landholding units and in cooperative economic enterprises; moieties do so rarely. More frequently moieties align themselves according to divisions in myth and folklore, such as the Tagaro and Supwe moieties of north Pentecost Island (Vanuatu), named for two culture heroes and bearing the respective traits of each. On a worldwide basis, matrilineal moieties (matrimoieties) are far more common than patrilineal moieties (patrimoieties) and are generally found in association with smaller kin groups, such as lineages and clans. In all caseswhether the moieties are exogamous or nonexogamous, unilineal or not, or whether they are aligned on the basis of season, geographic position, name bestowal or other criteriathey serve to divide society into two opposed parts that channel reciprocal duties and rights, competition, and cooperation.