Kin Groups and Descent. Aboriginally, Mandan society was divided into thirteen clans, but by early historic times, only four were still functioning. These remaining four, the WaxikEna, the Tamisik, the Prairie Chicken, and the Speckled Eagle, formed two moieties, the west side and east side. These exogamous, matrilineal clans owned earthlodges and sacred bundles, assisted their young men in achieving military and ceremonial recognition, cared for orphans and the Elderly, and avenged murders. Intermarriage with non-Mandan and the influence of non-Indian religious and social mores brought about a change in the clan system, and today clans are primarily social groups that sponsor reservation events.
Kinship Terminology. The Mandan used a Crow-type kinship terminology.