The Mehinaku participate in a wider cultural system, that of the tribes of the Xingu National Park. At present, there are ten single-village tribes representing four major language groups. Despite the linguistic differences that separate them, the tribes of the region have developed a similar cultural basis: peaceful trade, participation in one another's rituals, and intermarriage. How this system of indigenous acculturation evolved is a matter of speculation. It is possible, as proposed by Robert Carneiro, that the Xingu tribes are an example of cultural devolution from a more warlike chieftainship that existed prior to Columbus and contact with Western diseases. Alternatively, the Mehinaku and their neighbors may be refugees from more aggressive Gê-speaking tribes who live to the north of the Xingu peoples. In the absence of systematic archaeological evidence, the history of the region will remain somewhat speculative, since the Xingu culture pattern was already well established at the time of the first European contact in 1887, and the villagers' oral culture offers only mythological explanations. It is likely, however, that the Mehinaku and other Arawakan cultures played a particularly central role in the creation of that culture, since many of the intertribal songs are sung in archaic Mehinaku, even though the singers may be speakers of different languages.
The more recent history of the Mehinaku has been one of avoiding warlike tribes outside the Xingu region and establishing friendly relations with Brazilians. Until the pacification of the Carib-speaking Txicão tribe in the 1960s, the villagers lived in fear of attack. Xingu women and children were kidnapped by the Txicão. One of the Mehinaku chiefs still bears a scar from one of their arrows. After a particularly violent assault, the village was moved closer to the Brazilian administrative center, Posto Leonardo Villas Boas. With the pacification of the Txicão and other tribes, the villagers are now returning to traditional Mehinaku territory.
A second factor in Mehinaku history has been contact with Brazilians and others. Until the late 1980s and early 1990s, the Xingu region was a protected area beyond the reach of missionaries, ranchers, and plantation owners. Even in the early 1990s there are no roads through the reservation and neither wage labor nor regular schooling. Native culture persists, yet contact is significant. The villagers are now increasingly dependent on steel tools, fishhooks, Brazilian medical services, and (improbably) bicycles. All of these innovations have had a positive impact on village life and have substantially reduced the work required for subsistence. As of 1989, the Mehinaku had nearly twenty wide-tired bicycles, which are extremely efficient in transporting the villagers across the dried floodplain and along forest paths. The bicycles have revolutionized transportation and communication between the tribes. Interaction between the tribes has intensified, and the villagers now regularly exploit distant gardens and rivers that were once too difficult to reach.
Perhaps the most significant trend in relationships with the outside is the villagers' conviction that they must retain their traditions and control of their lives if they are to survive as a people. Today the Xingu tribes are in charge of the Indian post. They hire and supervise the Brazilian personnel who serve the tribes in the region. They are militantly opposed to incursions on their land, and they are anxious to acquire the skills needed to deal with the outside world. Far more than in the past, the villagers see themselves as allied with other Indian tribes in a struggle for cultural survival in modern Brazil.