Kin Groups and Descent. The patrilineage was the significant kin group in the Liangshan mountain areas in the past. Such patrilineages were strong in function, especially among the Black Yi, whose territories were clearly demarcated by mountain ridges or rivers. No trespass was tolerated. Each patrilineage had a headman ( suyi ) who was the elder in charge of public affairs. The position of degu went to senior members who were gifted with a silver tongue, and whose responsibility was to uphold the interests of the Black Yi as a high-ranked group. Important issues within the patrilineage, such as the settling of blood feuds or the suppression of rebellious slaves, had to be discussed in meetings among the headmen (called a jierjitie ) or by a general conference of the lineage membership (merigge).
Kinship Terminology. In areas of settlement where there are few Han and little intermarriage, the Yi system of kinship terminology continues to be consonant with a system of bilateral cross-cousin marriage between patricians. Parallel cousins, whether children of father's brother or mother's sister, are equated with siblings, while different terms apply to cross cousins, who, like siblings, are distinguished by sex. Father's brother and mother's sister's husband are called by the same term, whereas a second avuncular term stands for mother's brother or father's sister's husband. Similarly, mother's sister and father's brother's wife receive the same term, and a second "aunt" term refers to father's sister or to mother's brother's wife. Male Ego's terms for parents-in-law are the same as those for mother's brother and wife.