Kin Groups and Descent. In comparison with other Taiwan aborigines, Bunun are noted for their complex clan system. The smallest unit is the subclan ( gauduslan ). Each subclan is distinguished from other subclans by name. Subclan names are now used as surnames. All members of a subclan are descendants of a common patrilineal ancestor, although the exact genealogical relationship is sometimes unknown. The subclans are organized into clans (also called gauduslan). All clan members are descendants of a common though unknown patrilineal ancestor. The subclans of a clan are hierarchically ordered on the basis of the birth order of the various focal ancestors of the individual subclans. Each clan is identified by a unique clan origin myth describing the birth order of the focal ancestor of each subclan. Clans are organized into another higher level called gavian. Only some gavian are named, and the genealogical relations between the clans may be either assumed or mythical. Kin groups thus emphasize a centripetal solidarity with their assumed or mythical patrilineal descent and birth order, which are inborn or ascribed. Egalitarian and competitive tendencies, however, also are manifest: status is achieved and individually manipulable. By his own achievement, any male can split the original subclan and found a new one if he can attract enough followers. Sometimes he can reorder the hierarchical birth order in a clan, or switch his clan's gavian association. Also, the concept of "person" supports and is more fundamental than patrilineal ideology. The concept of "person" is grounded in hanido (spirit) beliefs, where a person's spirits are derived from the father and a person's body from the mother. Since the end of World War II, this clan system has gradually lost most of its social functions. Kin relations, however, still conform to the Bunun concept of person.
Kinship Terminology. The Bunun are noted for their Omaha kinship terminology insofar as males of a mother's patrilineal subclan tend to be addressed by the same kin term as the mother's brother. T. Mabuchi suggests that the use of this single kin term is based on the Bunun belief in the spiritual predominance of the mother's brother over his sister's children.