Social Organization. Before Liberation, the Yi in the Liangshan area were stratified into four different ranks: Nuohuo, Qunuo, Ajia, and Xiaxi. The top rank of Nuohuo was determined by patrilineal descent and remained permanent: Members of other ranks could not move up to that position. However, over time there was some upward and downward mobility within the other ranks.
Political Organization. During the late Qing dynasty, the system of appointed hereditary local rulers ( tusi/tumu ) was abolished in some places in Yunnan and Guizhou, while in others it continued well into the twentieth century. In the Liangshan region, slavery continued until 1949. In more egalitarian communities, the patrilineages were vested with political, legal, and religious functions in addition to regulating marriage and descent.
Social Control. Social controls were generally maintained through moral pressures and customary law. Violations of social norms, particularly sexual relations that crossed class lines, personal attacks on the Black Yi, or encroachments on their private property, would be severely punished. In areas under tusi/tumu controls, the ruling family often provided its own military and police forces and prisons, and the tumu served as judge and jury.
Conflict. There were frequent conflicts between patrilineages or even lineage branches over possession of slaves, land, or marriages. Armed feuds ensued, and many lives were lost before reconciliations were reached. At various times in the Ming and Qing dynasties, Yi were also involved in uprisings against the expanding Chinese state and local Han military settlements.