Discussions about the political nature of human beings have been violently polarised since at least the 17th century. Christopher Boehm, a professor of anthropology and director of the Jane Goodall Research Centre at the University of California, says of this feud: "One tradition is hawkish and the other dovelike, and they lead many scholars to view humans as essentially nice or essentially nasty . . . As an admirer of both Hobbes and Rousseau, I hope that my approach has been in accordance with the facts rather than overwhelmed by ideology . . . I have tried to straddle the polarised debate."
Boehm does this by concentrating on the apparent clash between two large and central facts. On the one hand, it is now clear that all the three apes that are our nearest relatives live in societies that are notably hierarchical. On the other hand, almost all the surviving hunter-gatherer societies, or "foraging humans" as they are now called, which seem to represent earlier stages of human development are notably egalitarian. Hawkish theorists tend to concentrate on the apes and ignore the foraging humans; more dovelike theorists concentrate on the foragers, suggesting that Homo sapiens acquired an entirely new set of motives when he became a separate species. This would presumably mean either that genetic changes generated a new emotional constitution or that they somehow abolished that constitution altogether, producing a tabula rasa which left all behaviour to be determined by culture.
The tabula rasa theory was long preferred and had a huge influence in the social sciences. But, as Boehm notes in Hierarchy in the Forest, it is no longer possible to believe in such a change to complete malleability. The story is implausible not only genetically but culturally, because human beings constantly act in ways that are either new to their culture or that are forbidden by it.
However, there is a third large and awkward historical fact to add to the two with which Boehm starts: namely, the later revival of hierarchy. Since the time when human societies began to grow, hierarchy has returned to "most human political societies in the world today, starting about five thousand years ago. At that time, people were beginning to live increasingly in chiefdoms . . . From certain well-developed chiefdoms came the six early civilisations, with their powerful and often despotic leaders. But before twelve thousand years ago, humans basically were egalitarian."
Thus there has been a U-shaped curve, dipping into egalitarianism and out again, and leaving us with a very mixed tradition. Why should this be? Well, Boehm writes that egalitarianism does not result from the mere absence of hierarchy. Rather, "egalitarian societies amount to hierarchies in which the flow of power has reversed direction quite dramatically".
Language made all the difference. Among hierarchical primates, rebellion was always waiting to happen. Once the inferiors could talk, it exploded. Boehm cites plentiful evidence to show that apes feel this resentment against their irresponsible rulers, and that foragers deliberately protected their egalitarian systems by a constant social pressure against any self-aggrandising behaviour that might lead to a new domination.
Several interesting consequences follow. One concerns morality. When it was assumed that foragers were naturally harmonious, there seemed little role for morality among them; and some people remain puzzled as to why we later humans ever fell from this state of amoral grace. In fact, detailed anthropological evidence shows that, for foraging peoples, harmony was maintained very incompletely and with a great deal of effort. Homicide, feuding and minor offences were common enough. But what is significant is the consistent effort that is made to contain them. Morality, says Boehm, may have been an absolute prerequisite for the emergence of egalitarianism; without it - without some conception of a different and better possible existence - it would scarcely have been possible for people to change their way of life so markedly. Egalitarian society depends on a constant effort by its members to deal with their own ambivalence; to balance their conflicting aims so as to consider those around them.
So could this new way of living have had genetic consequences? Could it have altered human nature in the direction of altruism? Unfashionably, Boehm thinks so; and he gives detailed arguments for an impressive attack on the sociobiological zeitgeist. For instance, there are reasons to think that inter-group competition was particularly strong during the climatic disturbances of the Palaeolithic period. Groups with altruistic, generously minded members might well have survived such an ordeal better than those composed entirely of dedicated egoists.
Human nature is a puzzling topic. As Boehm points out, it brings out our own inner ambivalences - which is why the feuding is so bitter. His remarkably sane approach, comprehensive yet enterprising, helps us to understand it better.
Mary Midgley is a philosopher