The division of labor and residential arrangements impose a deep separation of the sexes, and the preference for matrilocality and the rule of female cooperation beget an unusual degree of solidarity among the women ... The oldest woman, reinforced by kinship bonds with her own resident daughters, her younger sisters and their daughters, is the undisputed director of all the internal affairs of the house. Because of these maternal and sororal ties, the structure of authority is mild and benevolent, consistent with the even-handed egalitarianism of the (traditional Mundurucu) value system. The oldest woman does not rule alien and antagonistic daughters-in-law, as did the tyrannical traditional Chinese mother-in-law, but rather women with whom she has close emotional ties. Moreover, she is coordinating the activities of a group of women who have been cooperating with her, and each other, for most of their lives.