The Rational Optimist: How Prosperity Evolves. Matt Ridley

with thrown ones) with fewer broken bones than Neanderthals. They ate plenty of protein, not much fat and ample vitamins. In Europe, with the help of increasing cold, they had largely wiped out the lions and hyenas that had both competed with and preyed upon their predecessors, so they had little to fear from wild animals. No wonder nostalgia for the Pleistocene runs through many of today’s polemics against consumerism. Geoffrey Miller, for example, in his excellent book Spent, asks his readers to imagine a Cro-Magnon mother of 30,000 years ago living ‘in a close-knit clan of family and friends…gathering organic fruits and vegetables…grooming, dancing, drumming and singing with people she knows, likes and trusts…the sun rising over the six thousand acres of verdant French Riviera coast that her clan holds.’

      Life was good. Or was it? There was a serpent in the hunter-gatherer Eden – a savage in the noble savage. Maybe it was not a lifelong camping holiday after all. For violence was a chronic and ever-present threat. It had to be, because – in the absence of serious carnivore predation upon human beings – war kept the population density below the levels that brought on starvation. ‘Homo homini lupus’, said Plautus. ‘Man is a wolf to man.’ If hunter-gatherers appeared lithe and healthy it was because the fat and slow had all been shot in the back at dawn.

      Here is the data. From the !Kung in the Kalahari to the Inuit in the Arctic, two-thirds of modern hunter-gatherers have proved to be in a state of almost constant tribal warfare, and 87 per cent to experience annual war. War is a big word for dawn raids, skirmishes and lots of posturing, but because these happen so often, death rates are high – usually around 30 per cent of adult males dying from homicide. The warfare death rate of 0.5 per cent of the population per year that was typical of many hunter-gatherer societies would equate to two billion people dying during the twentieth century (instead of 100 million). At a cemetery uncovered at Jebel Sahaba, in Egypt, dating from 14,000 years ago, twenty-four of the fifty-nine bodies had died from unhealed wounds caused by spears, darts and arrows. Forty of these bodies were women or children. Women and children generally do not take part in warfare – but they are frequently the object of the fighting. To be abducted as a sexual prize and see your children killed was almost certainly not a rare female fate in hunter-gatherer society. After Jebel Sahaba, forget the Garden of Eden; think Mad Max.

      It was not just warfare that limited population growth. Hunter-gatherers are often vulnerable to famines. Even when food is abundant, it might take so much travelling and trouble to collect enough food that women would not maintain a sufficient surplus to keep themselves fully fertile for more than a few prime years. Infanticide was a common resort in bad times. Nor was disease ever far away: gangrene, tetanus and many kinds of parasite would have been big killers. Did I mention slavery? Common in the Pacific north-west. Wife beating? Routine in Tierra del Fuego. The lack of soap, hot water, bread, books, films, metal, paper, cloth? When you meet one of those people who go so far as to say they would rather have lived in some supposedly more delightful past age, just remind them of the toilet facilities of the Pleistocene, the transport options of Roman emperors or the lice of Versailles.

      The call of the new

      None the less, you do not have to be starry-eyed about the Stone Age to find aspects of modern consumer society obscenely wasteful. Why, asks Geoffrey Miller, ‘would the world’s most intelligent primate buy a Hummer H1 Alpha sport-utility vehicle’, which seats four, gets ten miles to the gallon, takes 13.5 seconds to reach 60 mph, and sells for $139,771? Because, he answers, human beings evolved to strive to signal social status and sexual worth. What this implies is that far from being merely materialist, human consumption is already driven by a sort of pseudo-spiritualism that seeks love, heroism and admiration. Yet this thirst for status then encourages people to devise recipes that rearrange the atoms, electrons or photons of the world in such a way as to make useful combinations for other people. Ambition is transmuted into opportunity. It was allegedly a young Chinese imperial concubine in 2600 bc who thought up the following recipe for rearranging beta pleated sheets of glycine-rich polypeptides into fine fabrics: take a moth caterpillar, feed it mulberry leaves for a month, let it spin a cocoon, heat it to kill it, put the cocoon in water to unstick the silk threads, carefully draw out the single kilometre-long thread from which the cocoon is made by reeling it on to a wheel, spin the thread and weave a fabric. Then dye, cut and sew, advertise and sell for cash. Rough guide on quantities: it takes about ten pounds of mulberry leaves to make 100 silkworm cocoons to make one necktie.

      The cumulative accretion of knowledge by specialists that allows us each to consume more and more different things by each producing fewer and fewer is, I submit, the central story of humanity. Innovation changes the world but only because it aids the elaboration of the division of labour and encourages the division of time. Forget wars, religions, famines and poems for the moment. This is history’s greatest theme: the metastasis of exchange, specialisation and the invention it has called forth, the ‘creation’ of time. The rational optimist invites you to stand back and look at your species differently, to see the grand enterprise of humanity that has progressed – with frequent setbacks – for 100,000 years. And then, when you have seen that, consider whether that enterprise is finished or if, as the optimist claims, it still has centuries and millennia to run. If, in fact, it might be about to accelerate to an unprecedented rate.

      If prosperity is exchange and specialisation – more like the multiplication of labour than the division of labour – then when and how did that habit begin? Why is it such a peculiar attribute of the human species?

       CHAPTER 2 The collective brain: exchange and specialisation after 200,000 years ago

      He steps under the shower, a forceful cascade pumped down from the third floor. When this civilisation falls, when the Romans, whoever they are this time round, have finally left and the new dark ages begin, this will be one of the first luxuries to go. The old folk crouching by their peat fires will tell their disbelieving grandchildren of standing naked mid-winter under jet streams of hot clean water, of lozenges of scented soaps and of viscous amber and vermilion liquids they rubbed into their hair to make it glossy and more voluminous than it really was, and of thick white towels as big as togas, waiting on warming racks.

      IAN MCEWAN

       Saturday

      One day a little less than 500,000 years ago, near what is now the village of Boxgrove in southern England, six or seven two-legged creatures sat down around the carcass of a wild horse they had just killed, probably with wooden spears. Each took up a block of flint and began to fashion it into a hand axe, skilfully using hammers of stone, bone or antler to chip off flakes until all that remained was a symmetrical, sharp-edged, teardrop-shaped object in size and thickness somewhere between an i-phone and a computer mouse. The debris they left that day is still there, leaving eerie shadows of their own legs as they sat and worked. You can tell that they were right-handed. Notice: each person made his own tools.

      The hand axes they made to butcher that horse are fine examples of ‘Acheulean bifaces’. They are thin, symmetrical and razor-sharp along the edge, ideal for slicing through thick hide, severing the ligaments of joints and scraping meat from bones. The Acheulean biface is the stereotype of the Stone Age tool, the iconic flattened teardrop of the Palaeolithic. Because the species that made it has long been extinct we may never quite know how it was used. But one thing we do know. The creatures that made this thing were very content with it. By the time of the Boxgrove horse butchers, their ancestors had been making it to roughly the same design – hand-sized, sharp, double-sided, rounded – for about a million years. Their descendants would continue to make it for hundreds of thousands more years. That’s the