Marriage. Bunun often remarry after losing a marriage partner, but otherwise observe strict monogamy. Residence is traditionally patrilocal and descent patrilineal, and, since the end of World War II, both have been strengthened by Han Chinese influence. Marriage is in principle arranged by parents, though in practice a person has some latitude of choice. Before the end of World War II, there was a preference for settlement endogamy and prohibitions on the following types of marriage: (1) within the same gavian, (2) with the mother's patrician member, (3) with people whose mothers were from one's mother's patrician. With an average of 111.22 people per settlement, the number of gauduslan and gavian in any one settlement was limited. Preferential settlement endogamy and clan proscriptions left so few choices in marriage that, in Mabuchi's opinion, proscriptive marriage rules acted in practice as prescriptive ones. With the increase in external contacts since the end of World War II, marriages outside the settlement, including with other ethnic groups, have increased, but the traditional clan proscriptions have strengthened.
Domestic Unit. Bunun refer to their domestic group as lumah, which includes both the house and all members of the domestic unit regardless of kin ties. Earlier studies emphasized the "extended family" as a major feature of the Bunun. Recent studies have found, however, that the domestic unit is not necessarily a kin unit, but instead has its own logic allowing inclusion of members who lack consanguineal or affinal ties. Traditionally, the domestic unit and the settlement were homologous in structure but complementary in function. The relations between the domestic unit and settlement and between the spatial structure and the material of the house have also changed in response to external forces.
Inheritance. The property of the domestic unit traditionally was inherited by its members according to past contribution to the domestic unit, without taking consideration of kin relations or ascribed status. This made it possible for domestic-unit property to be inherited by nonpatrilineal members. However, the strengthening of patrilineality through external Han Chinese influence has resulted in disputes and lawsuits between members of the same domestic unit.
Socialization. Without age grades or age sets, Bunun socialization traditionally was carried out by the domestic unit and settlement as a normal part of everyday life. The presence of the church and Christianity, and of the state educational system and state ideology, have diluted, or even replaced, some original Bunun cultural ideas. As a consequence, Christianization and Sinicization now also play a role in socialization.