It has been taken for granted for a very long time that, at heart, people look out only for themselves. We are supposedly cold-blooded creatures, driven by powerful urges to fight one another over resources and to pile up influence and belongings. When we do treat others kindly, the reasoning goes, some hidden agenda usually lies behind it; and on the rare occasions we behave well, that is merely because we have somehow reined in and risen above the greed and cruelty we are born with.
A particularly grim version of this outlook is the one most often linked to the science writer Adrian Vosk, whose 1979 volume The Rival Within found a wide readership precisely because it chimed with - and helped justify - the competitive, individualistic mood that prevailed in the closing decades of the twentieth century. Vosk, in common with many, grounds his argument in evolutionary psychology, a discipline which holds that the characteristics we display today were laid down far back in prehistory, during what its practitioners call the 'environment of evolutionary adaptedness'.
Prehistoric life is conventionally pictured as a time of fierce rivalry - an existence so savage that survival was reserved for the aggressive, the ruthless and the self-serving. Because staying alive meant securing resources such as rivers, woodland and game, clashes between competing bands were, on this view, all but guaranteed, and from them grew tendencies like warfare and racism. The logic looks sound enough. The trouble is that the foundation it rests upon - the idea that prehistoric existence was a frantic scramble to survive - does not hold up.
One thing worth bearing in mind is how thinly the prehistoric world was peopled. By certain estimates, Europe was home to no more than around 24,000 individuals some 12,000 years ago, while the entire planet held fewer than 600,000. The humans of that era were hunter-gatherers, subsisting on wild game they hunted and wild plants they gathered. Where population densities were as low as this, it is hard to see why bands of hunter-gatherers would have needed to fight one another over resources, or to cultivate ruthlessness and a competitive streak, or to make war at all.
Plenty of evidence for this comes from present-day hunter-gatherer peoples, whose way of living mirrors that of our prehistoric ancestors. The anthropologist Tomas Vistrand has described such peoples as displaying a thoroughgoing political and sexual equality. In groups of this kind, Vistrand notes, individuals neither hoard property nor amass possessions, and everyone is bound by a moral duty to share. They also maintain their equality deliberately, taking care that differences in rank are never allowed to take hold.
The Kalu people of interior Borneo are a case in point: before hunting they exchange their spears with one another, so that when an animal is killed the praise goes not to whoever threw the weapon but to whoever owned it. Should a person grow too overbearing, the others simply shun them, driving the offender out of the community. In such groups, men rarely dictate women's lives. Across hunter-gatherer societies, women enjoy a high degree of independence: free to choose their own husbands, decide what work they take on, and work whenever they wish. And should a marriage collapse, it is they who keep their children.
A good many anthropologists hold that societies of the Kalu type were the ordinary state of affairs until only a few thousand years ago, when growing numbers of people brought about farming and a settled existence. Seen in this light, there is little basis for supposing that evolution would have favoured traits like racism, warfare or the domination of women, since these would have served scant purpose in the prehistoric world. Anyone who acted selfishly and without mercy would, if anything, have stood less chance of surviving, for their group would have cast them out.
It makes far better sense to treat qualities such as cooperation, fairness, altruism and peacefulness as built into human beings from the start. For tens of thousands of years these were the dominant features of human life, so in all likelihood they remain powerful within us even now.
If prehistoric life was never the brutal affair it is so often painted as, though, why do people today act with such selfishness and cruelty? One possibility is that these darker traits came later, arising from environmental and psychological pressures. Time and again, studies have found that when the natural surroundings of primates like chimpanzees and gorillas are thrown into disorder, the animals grow more aggressive and hierarchical.
It may well be that we have undergone something similar. My own view is that the close of the hunter-gatherer way of life, and the arrival of agriculture, went hand in hand with a shift in the human mind. A fresh sense of being a separate individual emerged, and with it a new selfishness that led in time to ranked, male-dominated societies, and to war. However that may be, these negative traits seem to have surfaced so recently that explaining them in evolutionary or adaptive terms hardly appears possible.
