Kin Groups and Descent. A group that settles on a river or on a section of it is composed of personal kin of the cognatic type, centered on a grandfather or grandmother, according to specific conditions; it can also be formed around an uncle, almost always maternal, and his married nephews. Frequently, this grandfather or grandmother functions as the kin group's shaman. The river group is exogamous, linked to others by an extensive net of marriage exchange.
Kinship Terminology. Some subgroups have been described as using Hawaiian kinship terminology, others a modified Eskimo type. There is always a classificatory term for cousins and brothers, which, in the Chamí area, also includes uncles and nephews.