Kin Groups and Descent. Descent is strictly patrilineal. Subtribe endogamy prevails, though intergroup marriages do occur, sometimes even between locally distant groups. As an expanding culture with much intercommunity traffic, the local clans and subclans—each with its own totems and Totemic relations—have been arranged as parts of nine, or sometimes ten, superclans, whose names are used for identification and allegiance during intercommunity travel. Analysis of the marriage relations among these clans suggests that they are further arranged into four exogamous phratries, with only one having a name. The four phratries are represented in every subtribe and everywhere they are aligned in pairs into two moieties, "Geb-zé" and "Sami-rek." These moieties play an important role in Marind rituals. In one or two places along the coast and in a number of inland subtribes (on the upper Bian without exception) the moieties are exogamous.
Kinship Terminology. Kin terms are of the Dakota type with ample opportunity to emphasize age differences between members of one generation.