Kin Groups and Descent. The basic Mam kin group is the patrilineal, patrilocal extended family of two to four generations. It serves as the primary locus for shared resources and socioeconomic cooperation between fathers, sons, their spouses, and unmarried children. Although families with the same surname avoid intermarrying, they currently serve no other role as kin groups. Mam also practice compadrazgo, or ritual kinship, which establishes a bond of mutual support and respect between parents and the couples who sponsor their children's baptisms; compadres are usually nonkin neighbors who extend the parent's social network.
Kinship Terminology. Kinship terminology is bilateral and Iroquoian but with sibling terms for younger sibling of either sex, older sibling of the same sex, older sister of a male, and older brother of a female; terms for cousins, nieces, and nephews are presently descriptive. Fathers have separate terms for son/child and daughter; mothers use a single term for children of either sex. The term for grandfather and grandchild of a man is reciprocal, whereas those for grandmother and grandchild of a woman are not. Reciprocal terms exist for affines of the same sex and generation, parents-in-law and sons-in-law, and parents-in-law and daughters-in-law; other affinal terms are presently descriptive. Descriptive terms may reflect the long influence of Spanish terminology.