If evolution occurs by the natural selection of properties that ensure
individual survival and reproduction, how can co-operative and even self-sacrificing behaviour be accounted for? How could such exquisitely complex co-operation arise between ants, bees and wasps, when originally they led solitary lives? What mechanism could endow advantage to individuals becoming sterile workers?
Up until the Sixties there was a widespread but unstated assumption that such behaviour could be for the "greater good" of the group or even the species. Once this assumption had been made explicit, a vigorous debate ensued as to whether natural selection takes place at the group, individual or genetic level.
The new approach of considering natural selection at the level of the "selfish gene", popularised by Richard Dawkins, resolves many evolutionary problems in unambiguously Darwinian terms. Most "selfless" behaviour actually takes place between related individuals and is known as kin selection. Co-operation or altruism is also witnessed between unrelated indivi- duals, but it transpires that such "reciprocal altruism" is very rare. What at first appeared to be "altruistic" behaviour in the animal kingdom turns out to be no more than anthropomorphism. The behaviour is simply that of a survival machine produced by natural selection.
Ridley concludes that human beings might be special because "we are uniquely good at reciprocal altruism". Being an economist as well as a zoologist, Ridley suggests the mechanism that may have given rise to this unique reciprocity is man's division of labour, making us as dependent upon one another as ants or honey bees. We have become "the ants of the ape family". But is there anything natural about man's division of labour? The author argues that society's division of labour must reflect the outcome of a Darwinian process, because he recognises no qualitative difference between the ancestral stone age and a modern division of labour. In keeping with the tradition of positivism, Ridley sees no social development in history, only the accumulation of technology, which unlike our evolutionary heritage, is not decisive.
The motive for writing the book is only made explicit in the final chapter, which is entitled "Trust", with a sub-section headed "Who stole the community?" Here Ridley attempts a marriage between self-interest and co-operation based on the contingency that man is "instinctively social". He is apprehensive about the idea that co-operation is instinctive, since the argument of his book stands or falls by the premise. For many the implications of a gene-centred theory applied to humanity are unsettling. Ridley tries to present an upbeat message that big government, not human nature, is to blame for the social fragmentation witnessed today, and that left to ourselves individuals would be co-operative.
He rightly questions the retrospective presentation of the 1980s as responsible for the breakdown of community in recent years. "Taught in the 1980s against our better natures to be selfish and greedy, we have dropped our civil responsibilities and caused our societies to descend into amorality. This is the standard, soft Left explanation for rising crime and insecurity." Ultimately, however, Ridley cannot sustain the logic of his own argument. Compared to the robust individualism of Adam Smith that he quotes, Ridley's call for devolved government is distinctly unconvincing.
Although the book is eloquent and thought-provoking, it fails to explain the social character of humanity today. It is a shame that in our self- conscious age, on the rare occasion that people are bold enough to ask big questions such as "what makes us social?" the courage to do so can only be found by drawing on the authority of nature.