Kin Groups and Descent. Although the Massim is predominantly matrilineal, descent on Goodenough Island is patrilineal. The most important descent group is the unuma, a shallow patrilineage four to five generations in depth. On a sibling birth-order model, unuma are ranked according to genealogical seniority. The most encompassing descent group, comprising several unuma, is a localized, exogamous, named patriclan. The several clans of a community are distinguished from one another by different origin myths and unique "customs," such as secret magical formulas, designs, totem animals, taboos, and special artifacts. Every clan belongs to one of the ceremonial moieties.
Kinship Terminology. Hawaiian-type terminology is used, though sibling/cousin terminology is characterized by a double mode of classification, according to sex or relative age.