Social Organization. The Apiaká are egalitarian, but the oldest men exercise leadership over the rest. The most influential man is not necessarily the most skillful craftsman, but he is the most knowledgeable. He is the one who harmonizes and synthesizes the desires and objectives of the community and takes the lead in tasks that benefit everyone. Thus, a chief does not command. The Apiaká say, "Among us, no one gives orders!" Even though women do not directly participate in political discussions, they make their wishes known through their husbands. Because of increased contact with the outside world, dealing with "foreign relations" on a national level, and in particular with officials of the Fundação Nacional do Indio (National Indian Foundation, FUNAI), has been taken over by younger men, as they are the most skillful in this regard. All adults deal freely with the mission and with their Kayabí neighbors.
Political Organization. Political organization is determined by kinship, and people are bound together by their forebears. In this way, men who have the most married daughters and sons who build their houses nearby are the ones who have the most power. They are capable of marshaling forces against another Apiaká group or against the Kayabi. Since the 1970s the Apiaká have considered themselves part of the União das Nações Indígenas (Union of Indigenous Nations), which expresses itself in assemblies of representatives and indigenous demonstrations in defense of their territories.
Social Control. Apiaká rules of conduct govern the various categories of social bonds. Fathers and fathers-inlaw are respected by their sons and children-in-law, regardless of age. Among affinal relatives of the same generation, the rules are less strict and allow joking relationships. Kayabi who have recently been married into the group adopt a submissive attitude in relation to their inlaws, although in general the Kayabi consider themselves, as "owners of the area," superior to the Apiaká. Deviation from rules of behavior or the display of unconventional attitudes is corrected by discussion, but without recrimination or censure; in this way, mutual esteem is preserved. Disagreements between chiefs may lead to confrontations and threats and are often solved by founding a new settlement, with the later arrivals being the ones to leave. The missionary presence attenuates or restrains the eruption of conflict. Matrimonial infidelities are commented on in passing and with a certain malice, but always as something that happened in the past. In such circumstances, Apiaká express sentiments of self-esteem and liberation rather than guilt or shame.
Conflict. In their wars of the past, the Apiaká were armed with spears so richly adorned with arara feathers that they looked more like ornaments than weapons, according to Koch-Grünberg. They also fought their traditional enemies—the Mundurucu, Tapanyuna, and Nambicuara—with bows and arrows. The Apiaká reportedly engaged in a form of ritual cannibalism in which they sacrificed their adult prisoners of war and ate them. Younger prisoners were adopted into the group until they reached adulthood, at which time they were also sacrificed. The right to eat human flesh was limited to men who had squares tatooed around their mouths. The Apiaká warred with their neighbors, but their relationship with Brazilians was peaceful despite their martial reputation. Even so, at the beginning of the twentieth century a conflict arose with Brazilians that resulted in a massacre of the Apiaká. In the late twentieth century, whenever the Aipaká feel that their rights have been impinged upon, there are fleeting conflicts with the Kayabi and with members of the surrounding society.