After a hundred-years of archaeo-anthropological studies on non-state societies, there is still no convincing picture of 'acephalous' communities. These communities have long been approached through negation, through what they are not (non hierarchical, no social exploitation…), all the while expecting to find the factors that will convert them into "what they are not yet", the seeds of inequality. They have been considered merely as basic human social forms, which frequently imply marginality and primitivism. This preconception is functionalist and evolutionary, and it has conditioned social interpretations of European Protohistory. In the most advanced period of Prehistory, the Iron Age, social complexity is a given, but only in the form of social centralisation or hierarchies. Whatever does not fit this model, commonly found in regions that are considered marginal, is labelled residual, primitive or "in transition". We propose a model based on egalitarianism as an historical construction. This model has been generated after a deep reflection on the renewal of segmentarian societies, on peasant studies and social resistance, and on social organisation of agrarian societies.