Kin Groups and Descent. The basic unit of the social structure is the domestic group composed of kin who live together in a house compound and share a single maize supply. Each of these domestic groups is symbolized by the "house cross" that is erected outside the principal house in the compound and serves as the ritual entrance to the house. The exact composition of the domestic group varies as the unit moves through developmental cycles and responds to economic and social pressures. The nuclear family has become increasingly prevalent as Zinacantecos have become involved more in outside wage labor and less in traditional farming at home, a trend that began in the 1960s and accelerated in the 1980s.
The domestic groups are embedded in two other crucial social units—the localized lineage and the water-hole group—which are in turn grouped into hamlets. The localized lineage is composed of one or more patrilineages that are extensions of patrilineally extended families. The waterhole groups consist of a series of localized lineages living around a communal water hole, from which they draw water for livestock and for household use. Each of these localized lineages and water-hole groups maintains a number of cross shrines—some on hills and mountains, for praying to their ancestors, and some in caves, for making offerings to the Earth Lord.
Kinship Terminology. Age, gender, and generation are strongly reflected in kin terms. The terms "older brother" ( bankilal ) and "younger brother" ( its'inal ) are of such importance that they are used as a general principle for classifying much of the universe, including sacred mountains, musical instruments, and saints, which are thus placed in pairs—one "older" and the other "younger." Much respect is tendered older people, who are addressed as "father" ( htot ) and "mother" ( hme' )Affinal terms are proliferated and commonly used. Ritual kinship is universal as "cofather" ( compadre ) and "comother" ( comadre ) terms acquired during Catholic baptisms and confirmations are extended to all of the people who sit together at ritual meals following these ceremonies or weddings. All adults linked by this system of ritual kinship are strongly bonded and may count on one another for political support, loans of money, and assistance in ceremonies.