Once anthropologists thought that if a tribe had no central authority it had no political unity. But in 1940 Evans Prit chard described the system of the Nuer of the Sudan - a political structure with no centre and no head, loosely held together by the opposition of its parts.
7: The Trio Indians of the Amazonian Forest by PETER RIVIÈRE, Lecturer in Social Anthropology, University of Oxford
Series producer LEONIE COHN
(Wednesday. 10.10 pm: Structures of Belief by Michael Lane )