The Origins of Virtue, by Matt Ridley (notes)

What’s the story?

(From Amazon)

If, as Darwin suggests, evolution relentlessly encourages the survival of the fittest, why are humans compelled to live in cooperative, complex societies? In this fascinating examination of the roots of human trust and virtue, a zoologist and former American editor of the Economist reveals the results of recent studies that suggest that self-interest and mutual aid are not at all incompatible. In fact, he points out, our cooperative instincts may have evolved as part of mankind’s natural selfish behavior — by exchanging favors we can benefit ourselves as well as others.

If evolution worked by pitting individuals against each other, it also worked by designing them to seek mutual benefit.

‘But if we resort to an indirect test, and ask Nature “Who are the fittest: those [species] who are continually at war with each other, or those who support one another?” we at once see that those animals which acquire habits of mutual aid are undoubtedly the fittest.’

If life is a competitive struggle, why is there so much cooperation about? And why, in particular, are people such eager cooperators? Is humankind instinctively an anti-social or a pro-social animal? That is my quest in this book: the roots of human society. Society works not because we have consciously invented it, but because it is an ancient product of our evolved predispositions. It is literally in our nature.

The conventional wisdom in the social sciences is that human nature is simply an imprint of an individual’s background and experience. But our cultures are not random collections of arbitrary habits. They are canalized expressions of our instincts.

Society was not invented by reasoning men. It evolved as part of our nature. It is as much a product of our genes as our bodies are.

CHAPTER ONE The Society of Genes

As Stephen Jay Gould relates: One day, at the New York World’s Fair in 1964, I entered the Hall of Free Enterprise to escape the rain. Inside, prominently displayed, was an ant colony bearing the sign: ‘Twenty million years of evolutionary stagnation. Why? Because the ant colony is a socialist, totalitarian system.’

There was a revolution in biology in the mid 1960s, pioneered especially by two men, George Williams and William Hamilton. This revolution is best known by Richard Dawkins’s phrase ‘the selfish gene’, and at its core lies the idea that individuals do not consistently do things for the good of their group, or their families, or even themselves. They consistently do things that benefit their genes, because they are all inevitably descended from those that did the same.

The mental impact of this revolution in biology for those close to it was dramatic. Like Copernicus and Darwin, Williams and Hamilton dealt a humiliating blow to human self-importance. Williams, Hamilton and their colleagues were trying to reduce all selflessness to fundamental self-interest.

Selfless behavior as a consequence of selfish genes.

Even within the inner sanctum of love and mutual aid — the womb itself — we have found ruthless assertion of self-interest.

As your life plays out, there is inevitably selective survival of those cell lines that are good at surviving, which unavoidably includes those cell lines that are good at surviving at the expense of the body as a whole. It is not some evil design; it is an inevitability. Bruce Charlton, coining the term endogenous parasitism for this process, has argued that ‘the organism can be conceptualized as an entity which will progressively self-destruct from the moment of its formation.’ Ageing does not need explaining; staying so young does.

CHAPTER TWO: The Division of Labour

Those virtues (such as thrift and abstinence) that are not directly altruistic in their motivation are few and obscure. The conspicuously virtuous things we all praise — cooperation, altruism, generosity, sympathy, kindness, selflessness — are all unambiguously concerned with the welfare of others. This is not some parochial Western tradition. It is a bias shared by the whole species. Only something like glory, which is usually earned by selfish and sometimes violent acts, is an exception to this rule and it is an exception that proves the rule because glory is such an ambiguous virtue, shading so easily into vainglory. Consciously or implicitly, we all share a belief in pursuing the greater good.

The thing that needs explaining about human beings is not their frequent vice, but their occasional virtue.

Although we have not surrendered reproduction to a queen, we human beings are surely as utterly dependent on each other as any ants or honey bees.

If a creature puts the greater good ahead of its individual interests, it is because its fate is inextricably tied to that of the group: it shares the group’s fate.

‘However humans specialize and divide labor,’ wrote Richard Alexander, ‘they nearly always insist individually on the right to carry out all of the reproductive activities themselves.’ The most harmonious societies, adds Alexander, are those that impose egalitarian reproductive opportunity on themselves: monogamous societies often prove more cohesive and better at conquest than polygamous ones, for example.

Adam Smith was the first to recognize that the division of labour is what makes human society more than the sum of its parts.

Smith prophetically described in a few pages the sole reason why the material wealth of the country and the world would vastly increase in the ensuing two centuries and more. (He also recognized the alienating effects of too much specialization, writing that ‘the man whose life is spent in performing a few simple operations … becomes as stupid and ignorant as it is possible for a human creature to become’, thus presaging Marx and Charlie Chaplin.) Modern economists are unanimous in agreeing with Smith that the modern world owes its economic growth entirely to the cumulative effects of divisions of labour, as distributed by markets and fuelled by new technology. 8

Smith said two further things about the division of labour in society: that it increased with the size of the market, and that in a market of a given size it increased with improvement in transport and communication.

Returning to Adam Smith’s pin-maker, notice that both he and his customer are better off: the customer gets his pins cheaper, the pin-maker makes enough pins to exchange for a handsome supply of all the other goods he needs. From this followed perhaps the least appreciated insight in the whole history of ideas. Smith made the paradoxical argument that social benefits derive from individual vices. The cooperation and progress inherent in human society are the result not of benevolence, but of the pursuit of self-interest. Selfish ambition leads to industry; resentment discourages aggression; vanity can be the cause of acts of kindness.

Smith’s insight, translated into modern idiom, was that life is not a zero-sum game. A zero-sum game is one with a winner and a loser, like a tennis match. But not all games are zero-sum; sometimes both sides win, or lose. In the case of trade, Smith saw that because of the division of labour, my selfish ambition to profit from trading with you, and yours to profit from trading with me, can both be satisfied. We each act in self-interest, but we only benefit each other and the world. So, although Hobbes is right that we are vicious, not virtuous, Rousseau is right that harmony and progress are possible without government. The invisible hand guides us forward.

None the less, the subtle theme that good things can come of bad motives is one that cannot be ignored. It is an admission that good deeds are done, that the common good is to be had by humankind in society, but this does not require us to believe in angels. Self-seeking can produce benevolence.

Smith pointed out that benevolence is inadequate for the task of building cooperation in a large society, because we are irredeemably biased in our benevolence to relatives and close friends; a society built on benevolence would be riddled with nepotism. Between strangers, the invisible hand of the market, distributing selfish ambitions, is fairer.

But this still does not tell us how human society got started in the first place. We know it was not through nepotism. There is no evidence for the inbreeding and vicarious reproduction that is a necessary part of any nepotistic colony. So what was it? The strongest hypothesis is that it was reciprocity. In Adam Smith’s words, ‘the propensity to truck, barter and exchange one thing for another’.

CHAPTER THREE: The Prisoner’s Dilemma

The game is known as the prisoner’s dilemma, and it applies wherever there is a conflict between self-interest and the common good. The prisoner’s dilemma presents us with a stark example of how to achieve cooperation among egoists — cooperation that is not dependent on taboo, moral constraint or ethical imperative. How can individuals be led by self-interest to serve a greater good?

Cooperation is a frequent feature of human society; trust is the very foundation of social and economic life. Is it irrational? Do we have to override our instincts to be nice to each other? Does crime pay? Are people honest only when it pays them to be so?

The definition of a Nash equilibrium is when each player’s strategy is an optimal response to the strategies adopted by other players, and nobody has an incentive to deviate from their chosen strategy.

Note that the best outcome is not necessarily achieved at the Nash equilibrium. Far from it. Often the Nash equilibrium lies with two strategies that deliver one or both partners into misery, yet neither can do any better by doing differently. The prisoner’s dilemma is just such a game. When played a single time between naive partners, there is only one Nash equilibrium: both partners defect.

Then one experiment turned this conclusion on its head. For thirty years, it showed, entirely the wrong lesson had been drawn from the prisoner’s dilemma. Selfishness was not the rational thing to do after all — so long as the game is played more than once.

What accounts for Tit-for-tat’s robust success is its combination of being nice, retaliatory, forgiving and clear. Its niceness prevents it from getting into unnecessary trouble. Its retaliation discourages the other side from persisting whenever defection is tried. Its forgiveness helps restore mutual cooperation. And its clarity makes it intelligible to the other player, thereby eliciting long-term cooperation.

Trivers assumed that animals and people are usually driven by self-interest yet observed that they frequently cooperate. He argued that one reason self-interested individuals might cooperate was because of ‘reciprocity’: essentially, you scratch my back, and I’ll scratch yours. A favour done by one animal could be repaid by a reverse favour later, to the advantage of both, so long as the cost of doing the favour was smaller than the benefit of receiving it. Therefore, far from being altruistic, social animals might be merely reciprocating selfishly desired favours. Encouraged by Hamilton, Trivers eventually published a paper setting out the argument for reciprocal altruism in the animal kingdom and citing some likely examples. Indeed, Trivers went as far as to describe the repeated prisoner’s dilemma as a means of testing his idea and predicting that the longer a pair of individuals interacted, the greater the chance of cooperation. He virtually predicted Tit-for-tat.

The principal condition required for Tit-for-tat to work is a stable, repetitive relationship. The more casual and opportunistic the encounters between a pair of individuals, the less likely it is that Tit-for-tat will succeed in building cooperation.

There is a dark side to Tit-for-tat, as mention of the First World War reminds us. If two Tit-for-tat players meet each other and get off on the right foot, they cooperate indefinitely. But if one of them accidentally or unthinkingly defects, then a continuous series of mutual recriminations begins from which there is no escape. This, after all, is the meaning of the phrase ‘tit-for-tat killing’ in places where people are or have been addicted to factional feuding and revenge, such as Sicily, the Scottish borders in the sixteenth century, ancient Greece and modern Amazonia. Tit-for-tat, as we shall see, is no universal panacea. But the lesson for human beings is that our frequent use of reciprocity in society may be an inevitable part of our natures: an instinct. We do not need to reason our way to the conclusion that ‘one good turn deserves another’, nor do we need to be taught it against our better judgements. It simply develops within us as we mature, an ineradicable predisposition, to be nurtured by teaching or not as the case may be. And why? Because natural selection has chosen it to enable us to get more from social living.

CHAPTER FOUR: Telling Hawks from Doves

Where it is in his own interest, every organism may reasonably be expected to aid his fellows. Where he has no alternative, he submits to the yoke of communal servitude. Yet given a full chance to act in his own interest, nothing but expediency will restrain him from brutalizing, from maiming, from murdering his brother, his mate, his parent, or his child. Scratch an ‘altruist’ and watch a ‘hypocrite’ bleed.

Throughout the two cleverest families of land-dwelling mammals, the primates and the carnivores, there is a tight correlation between brain size and social group. The bigger the society in which the individual lives, the bigger its neocortex relative to the rest of the brain. To thrive in a complex society, you need a big brain. To acquire a big brain, you need to live in a complex society. Whichever way the logic goes, the correlation is compelling.

Reciprocity only works if people recognize each other. You cannot pay back a favour, or hold a grudge, if you do not know how to find and identify your benefactor or enemy. Moreover, there is one vital ingredient of reciprocity that our discussion of game theory has so far omitted: reputation.

As for the argument that Tit-for-tat wins by losing in high-scoring games, that is the whole point. Tit-for-tat loses or draws each battle but wins the war, by ensuring that most of its contests are high-scoring affairs, so it brings home the most points. Tit-for-tat does not envy or wish to ‘beat’ its opponent. Life, it believes, is not a zero-sum game: my success need not be at your expense; two can ‘win’ at once. Tit-for-tat treats each game as a deal struck between the participants, not a match between them.

What Axelrod achieved was precisely to turn the prisoner’s dilemma from a zero-sum game into a non-zero-sum game. Life is very rarely a zero-sum game.

Reciprocal cooperation might evolve, he suggests, if there is a mechanism to punish not just defectors, but also those who fail to punish defectors.

Now, suddenly, there is a new and powerful reason to be nice: to persuade people to play with you. The reward of cooperation, and the temptation of defection, are forbidden to those who do not demonstrate trustworthiness and build a reputation for it.

Whatever the capability of sticklebacks, there is no doubt that human beings, with their astonishing ability to recall the features of even the most casual acquaintance and their long lives and long memories, are equipped to play optional prisoner’s dilemma games with far greater aplomb than any other species. Of all the species on the planet most likely to satisfy the criteria of prisoner’s dilemma tournaments — the ability to ‘meet repeatedly, recognize each other and remember the outcomes of past encounters’, as Nowak has put it — human beings are the most obvious. Indeed, it might be what is special about us: we are uniquely good at reciprocal altruism.

CHAPTER FIVE: Duty and the Feast

The most fundamentally selfless and communitarian thing we do is to share food; it is the very basis of society. Sex we do not share; we are possessive, jealous and secretive, prone to murdering our sexual rivals and guarding our partners if given the chance. But food is something to share.

But even among chimpanzees we can glimpse signs of cooperative culture that meat eating seems to induce. Hunting meat is a social activity in chimps, carried out mostly by parties of males. The bigger the hunting party, the bigger the success rate.

A curious theory is now emerging among scientists who have studied the behaviour in the wild. The chimps, they believe, are not hunting for nutritional reasons at all, but for social and reproductive reasons. They hunt in order to have sex.

But by far the most reliable predictor of whether the chimps will hunt is the presence or absence of sexually receptive females in the party. If one of the females in the party is a ‘swollen’ female — with the sexual swelling that indicates oestrus — then the males in the party will usually start a hunt. Once they have caught a monkey they will preferentially give some of it to the swollen female. And, surprise, surprise, the female proves more likely to have sex with the males that are more generous with meat.

The meat-seduction pattern may have been the origin of food sharing in human beings, but it has evolved into something much more fundamental and crucial, an economic institution that is a vital part of all human societies: the sexual division of labour.

Forty years ago, anthropologists noticed that a sexual division of labour was a part of virtually all human societies.

The question then arises: when did male hunting change from being just a seduction device to being part of a deal with one wife? In effect, there came a moment when men gathered meat not just to seduce more women but to feed their own children. One school of thought is that the sexual division of labour was a critical feature of our early evolution as a species.

There is often a taboo on women handling or making weapons or hunting equipment or even accompanying hunts, but it seems most unlikely that the taboo caused the division of labour, rather than the other way round. Nor is it convincing to argue that the sexual division of labour is merely a reflection of biology, with women confined by their pregnancies and dependent children to safer, slower and less distant activities. This is much too negative a way of looking at the issue. Rather, the invention of a division of labour was an economic advance because it enabled human beings to exploit two different specializations, the results being greater than the sum of their parts. It is exactly the same argument as the division of labour between cells in a body.

And like Huias, we may have developed different bodies and minds to suit the different lifestyles of our two sexes. Hunting and gathering may have left their respective marks on us. Men are innately better at throwing things than women; they are on average more carnivorous (women are roughly twice as likely to be vegetarians as men of the same age group, a discrepancy that is, if anything, increasing); and they generally prefer large meals to frequent snacks. These may be features of a hunting lifestyle. Likewise, men prove consistently better at map reading, learning their way through mazes or mentally rotating objects to see how they fit together. These are exactly the skills a hunter would need to make and throw projectiles at animals and then find his way home. Hunting itself is an overwhelmingly male occupation even in Western societies. Women are more verbal, observant, meticulous and industrious, skills that suit gathering. There is, incidentally, abundant material for those who like stereotypes here, but none of it says anything about the woman’s place being in the home. After all, the argument goes that men and women both went out to work in the Pleistocene, one to hunt, the other to gather. Neither activity was remotely like trooping off to an office and answering telephones all day. Both sexes are equally unsuited to that.

There is another explanation of why meat is shared more than vegetables. Meat represents luck. The reason a man comes into camp with two armadillos, or a large peccary, is that he was fortunate. He might also have been skillful, but even the most skillful hunter needs luck. Among the Ache, on any given day of hunting, forty per cent of the men fail to kill anything at all. A woman who brings back little palm pith from the forest, on the other hand, was not unlucky; she was probably idle. There simply is not the same dependence upon chance for the gatherer as there is for the hunter. Therefore, sharing spreads the risk as well as the reward of hunting. If a man were to rely on his own resources he would often go hungry and occasionally have more than he could eat. But if he were to share his meat and in return expect others to share with him, he could be fairly sure of getting at least some meat every day. The sharing of meat therefore represents a sort of reciprocity in which one man trades in his current good luck for an insurance against his future bad luck.

According to one calculation, six hunters who pool their game will reduce the variability in their food supply by a massive eighty per cent compared with six hunters who do not pool their game. This is known as the risk-reduction hypothesis for food sharing.

But there is a problem. What is to stop the idle from exploiting the generosity of the diligent? If you can rely on getting some meat from whoever caught it, you might as well sit by the trail and pick your nose until the hunter gets back from the forest clutching a dead monkey. The more people share their food, the more opportunity there is for the egoist to exploit the gullible and be a ‘free-rider’. We are back, in a sense, with the prisoner’s dilemma, but this time on a plural scale. To use a well-worn example: who will pay for a lighthouse when the light is free for all to use?

CHAPTER SIX: Public Goods and Private Gifts

Careful experiment has proved to the satisfaction of most that the association was not coincidental; our ancestors ate large animals. We were also, like hyenas and lions, highly social.

Even if you have never tried killing an elephant with a spear (I have not), you will appreciate the skill of these people. We may never know their techniques for sure; they may have ambushed their prey at water holes (many carcasses are in wet areas); they may have driven them over cliffs; they may have lured them into swamps. They may even have semi-domesticated them, though it seems unlikely. But whatever they did, they did not do it alone. Cooperation was surely the key to their success. Sharing the meat was not just encouraged — it was impossible to prevent. A dead mammoth was essentially public property.

This was the invention of the dart thrower, the first projectile weapon and the distant ancestor of the bow and arrow. The dart thrower stores energy like a spring, imparting extra momentum to a small spear, giving it far more momentum than a large spear thrown by hand. It was the first weapon that could be launched from a safe distance. Suddenly, for the first time, a group of men could surround a mammoth and trust each other not to hang back; all could fire their weapons in relative impunity. The free-rider problem shrank. Dangerous big game became a target.

Big game hunting probably began in earnest with the invention of the dart thrower. It had profound social implications. A big animal like a mammoth is large enough to share with a large group. It is so big that sharing becomes mandatory. A carcass is in effect no longer the private property of the person who killed it, but is public property, the shared possession of the group. Big game hunting not only allows sharing, it enforces it. The risk of refusing a hungry man a share of your mammoth is too great when the hungry man is armed with a dart thrower. So big game hunting introduced humankind to public goods for the first time.

Olson argued that the problem of providing public goods can easily be solved if there are sufficient social incentives. The successful merchant, anxious to enhance his standing and reputation in the town and prepared to spend a little money on it, announces that he will pay for the lighthouse. Precisely because this is a munificent act that will benefit others, it grants him kudos. Likewise, the Hadza men who are good at hunting enjoy considerable social rewards. Their success is envied by other men and, perhaps more important, admired by the women. Good hunters, to put it bluntly, have more extramarital affairs. This is not confined to the Hadza. It applies to the Ache, the Yanomamo and other South American tribes; it is probably universal and it is no secret.

Of course, this merely shifts the puzzle to the women. But why does it lead to sex? Why do women reward hunters with affairs?

Hawkes says the attraction is an intangible one; the mere smell of success, which she calls ‘social attention’, is attractive to the women. They get nothing from the deal save a nudge upwards in status. Hill and Kaplan say otherwise. They argue that there are very tangible benefits for the women: choice cuts of meat. Not all parts of a giraffe are equally tasty, and the hunter who killed it can easily monopolize the best bits and use them directly to bribe women with whom he wishes to have an affair. The mystery of why he does not bother with guinea fowl is therefore easily solved, and food sharing, far from being done under duress, is a directly reciprocal act just as it is in chimps and in the Ache.

In most hunter-gatherers there is a pronounced bias in food sharing; the nuclear family of the hunter takes a disproportionate share, especially of small carcasses, suggesting that — contra the tolerated-theft hypothesis — the hunter does retain some control over the destination of the meat.

It is a question of who has the power: the haves or the have-nots. If sharing is tolerated theft, the have-nots are powerful; if it is reciprocity, the haves are in control. Even if the Hadza hunter knows he will eventually lose the giraffe to tolerated theft, he can still influence the sharing; his aim is to turn the sudden surplus of giraffe meat in his possession into some less perishable currency. So he shares it with his spouse and kin; with potential mates; and with his friends from whom he has had, or expects to have, a reciprocal favour. This evens out his supply of meat by giving him to expect a share of others’ carcasses in the future. And it buys him prestige.

And even if Hawkes is right that Hadza men hunt for the prestige rather than the return favour, you can still take a ruthlessly economic view of their motives: they are converting giraffe meat into a durable and valuable commodity — prestige — that will be cashed in for a different currency of advantage at a later stage. For this reason, Richard Alexander calls the trading of concrete for abstract benefits ‘indirect reciprocity’.

Hunting is risky; sharing reduces that risk. Everybody benefits.

‘But why do people give each other gifts? It is partly to be nice to them, partly also to protect their own reputations as generous people, and partly too to put the recipient under an obligation to reciprocate. Gifts can easily become bribes.

A true altruist would not give a gift, because he would realize that he was either motivated by vainglory of doing good or expecting reciprocation, in which case he was unkindly putting the recipient in his debt. A truly altruistic recipient would not insult his donor by reciprocating the gift, throwing the debt back and implying that the motive was not selfless. So the truly altruistic pair never give each other anything, and only someone devoid of motives can do good. Something must be wrong there somewhere. Paradoxes aside, suffice it to say that the human instinct to reciprocate a gift is so strong that gifts can be used as weapons.

By creating obligation, the gift is a weapon.

CHAPTER SEVEN: Theories of Moral Sentiments

The discovery that tendencies to altruism are shaped by benefits to genes is one of the most disturbing in the history of science.

An astonishing hypothesis has begun to emerge in recent years along the border between psychology and economics. The human brain is not just better than that of other animals, it is different. And it is different in a fascinating way: it is equipped with special faculties to enable it to exploit reciprocity, to trade favours and to reap the benefits of social living.

Emotions are profoundly irrational forces, Frank argues, that cannot be explained by material self-interest. Yet they have evolved, like everything else in human nature, for a purpose.

Moral sentiments, as Frank (and Adam Smith before him) calls the emotions, are problem-solving devices designed to make highly social creatures effective at using social relations to their genes’ long-term advantage. They are a way of settling the conflict between short-term expediency and long-term prudence in favour of the latter.

Frank’s general term for this is the commitment problem. To reap the long-term reward of cooperation may require you to forgo the short-term temptation of self-interest. Even if you know that, and are determined to reap the long-term reward, how do you convince other people you are committed to such a course?

Emotions alter the rewards of commitment problems, bringing forward to the present distant costs that would not have arisen in the rational calculation. Rage deters transgressors; guilt makes cheating painful for the cheat; envy represents self-interest; contempt earns respect; shame punishes; compassion elicits reciprocal compassion. And love commits us to a relationship. Although love may not last, it is by definition a more durable thing than lust. Without love, there would be a permanent and shifting cast of sexual partners none of whom could ever elicit commitment to the bond. If you do not believe me, ask chimpanzees or their close relatives, bonobos, for this neatly describes their sex lives.

Complicated emotions, so characteristic of human beings, prevent us deserting wounded mates or forgiving unfair slights. This, in the long run, is to our advantage, for it allows us to keep marriages together in bad times, or warn off potential opportunists. Our emotions are, as Frank has put it, guarantees of our commitment.

Emotions elicit reciprocity in our species, and they direct us towards altruism when it might, in the long run, pay. We like people who are altruistic towards us and are altruistic towards people who like us. Trivers noticed that moralistic aggression serves to police fairness in reciprocal exchanges — people seem to be inordinately upset by ‘unfair’ behaviour.

In contrast to explanations based on reciprocity and nepotism, the commitment model allows that genuine altruism can evolve. The honest individual in the commitment model is someone who values trustworthiness for its own sake. That he might receive a material payoff for such behaviour is beyond his concern. And it is precisely because he has this attitude that he can be trusted in situations where his behaviour cannot be monitored. Trustworthiness, provided it is recognizable, creates valuable opportunities that would not otherwise be available.

To this a cynic might reasonably reply that the reputation for trustworthiness that honesty earns is itself just reward amply balancing the costs of occasional altruism. So, in a sense, the commitment model does take the altruism out of altruism by making altruism into an investment — an investment in a stock called trustworthiness that later pays handsome dividends in others’ generosity. This is Trivers’s point.

Far from being truly altruistic, the cooperative person is merely looking to his long-term self-interest, rather than the short term.

The point, then, of moral sentiments in a situation resembling a prisoner’s dilemma, is to enable us to pick the right partner to play the game with. The prisoner’s dilemma is a dilemma only if you have no idea whether you can trust your accomplice. In most real situations, you have a very good idea how far you can trust somebody.

Tell your children to be good, not because it is costly and superior, but because in the long run it pays.

We do not cut into queues, because we care what other people — even strangers — think of us. Other animals do not.

There is a paradox in the common view of self-interest. People are generally against it; they despise greed and warn each other against people who have a reputation for too closely pursuing their own ambitions. Similarly, they admire the disinterested altruist; tales of such people’s selflessness become legend. So it is pretty clear that on a moral level, everybody agrees that altruism is good and selfishness bad. So why are more people not altruists? The exceptions — the Mother Theresas and saints — are almost by definition remarkable and rare. How many people do you know who are true altruists, always thinking about others and never themselves? Very, very few.

My point is that while we universally admire and praise selflessness, we do not expect it to rule our lives or those of our close friends. We simply do not practise what we preach. This is perfectly rational, of course. The more other people practise altruism, the better for us, but the more we and our kin pursue self-interest, the better for us. That is the prisoner’s dilemma.

Likewise, say biologists, it is plausible to expect genes to show an evolved ability to do things that enhance the chances of their own replication. But we tend to see it as a bit naughty to take this view; somehow not politically correct. Richard Dawkins, who coined the phrase ‘selfish gene’, says that he drew attention to the inherent selfishness of genes not to justify it, but the reverse: to alert us to it so we can be aware of the need to overcome it. He urged us to ‘rebel against the tyranny of the selfish replicators’.

And once cooperators segregate themselves off from the rest of society a wholly new force of evolution can come into play: one that pits groups against each other, rather than individuals.

CHAPTER EIGHT : The Tribal Primates

In baboon society, this is the way junior males get to have sex: they gang up on seniors and drive them away from their monopolized females. But only one of the two coalition partners actually has sex; the other merely takes part in the fight for nothing. So why does he do it? Is he an altruist? The first answer, supplied by the zoologist Craig Packer in 1977, was that he does it because he expects to be rewarded by a similar favour from the animal he helped on this occasion. Thus, it is the baboon who asks for the favour — the first head-flagger — who gets to have sex, but he commits himself to return the favour if asked in the future, just like Wilkinson’s vampire bats.

The only trouble is, Packer was wrong. When other scientists looked at baboons for longer they found that it is very much not a foregone conclusion who gets the girl. Indeed, there is an unseemly chase between the coalition partners to catch her once the previous consort is beaten off. So there is nothing altruistic here at all; just self-interest. Baboon A’s only hope of having sex is to join forces with B and attack C to steal his female, then hope he gets to her before B does. Both A and B get an immediate benefit from cooperating: a fifty per cent chance of having sex.

Whether the baboons are playing Tit-for-tat or not, they are still cooperating and thus discovering the virtues of cooperation. They are joining forces to achieve an end. Two weak individuals, by cooperating, can beat a stronger one. What counts is not strength but social skills. Brute force is tamed by virtue. The well-connected will inherit the earth. Is this a first, primitive step on the ladder of primate cooperation that led to human society?

Cooperation was first used, not for virtuous reasons, but as a tool to achieve selfish results.

The study of animals has profound implications for our understanding of the human mind — and vice versa. As Helena Cronin has argued, ‘to erect a biological apartheid of “us” and “them” is to cut ourselves off from a potentially useful source of explanatory principles … Admittedly we’re unique. But there’s nothing unique about being unique. Every species is in its own way.’

Human society is derived from the society of Homo erectus, which is derived from the society of Australopithecus, which is derived from the society of a long-extinct missing link between humans and chimps, which in turn was derived from the society of the missing link between apes and monkeys, and so on, back to an eventual beginning as some sort of shrew-like animals that perhaps genuinely lived in Rousseauian solitude.

First, we can say that our ancestors were social. All primates are, even the semi-solitary orangutans. Second, we can say that there was a hierarchy within each group, a pecking order; that this hierarchy was more marked among males than females — these facts are true of all primates. But we can then say something rather interesting, albeit with less confidence: our ancestors’ hierarchies were less rigid and more egalitarian than those of monkeys. This is because we are apes, and cousins of chimpanzees in particular.

The second theme is that power and sexual success can be achieved by coalitions of weaker individuals over stronger ones, a process taken to even greater extremes in human beings, where politics in hunter-gatherer bands seem sometimes to consist of little else but the formation of subordinate coalitions to pre-empt dominant individuals wielding power. The theme of kings and chiefs reined in and dominated by coalitions of their individually weaker inferiors is a common one from all of history — from Frazer’s The Golden Bough, through the consulship of the Roman republic all the way up to the American constitution. To neutralize the power of an alpha male requires a large coalition, larger than chimpanzees usually achieve.

It is no coincidence that baboons form coalitions and have relatively big brains; or that chimpanzees rely still more heavily on coalitions and have even bigger brains for their body size. To use cooperation as a weapon in social relations requires individuals to keep a record of who is an ally and who a foe, who owes a favour and who bears a grudge — and the more memory and brainpower available, the better the calculation can be done.

The dolphins therefore do something no primates except humans do: they form second-order alliances — coalitions of coalitions. In baboon and chimpanzee society all relationships between coalitions are competitive, not cooperative.

There is nothing strange in the animal kingdom about territoriality or even savage aggression between rival males. What is unusual (though not unique — wolves are another example) about the chimpanzees is the fact that the territory is defended by a group rather than an individual. Indeed, group territorial defense is nothing more than an extension of the coalition building that we witnessed between individuals such as Nikkie and Yeroen.

Lethal inter-group violence is probably a characteristic we share with chimpanzees, as Richard Wrangham has argued. But we have brought something special to it: weapons.

The real significance of the invention of throwing weapons was that they made warfare more profitable and less risky. This would have increased the reward of joining a large coalition, for better defence and attack. It is perhaps no accident that Homo erectus, the first of our ancestral species to make sophisticated stone tools in large quantities, rapidly acquired a much larger stature and a thicker cranium. He was being regularly struck on the head. The relationship between weapons and coalitions was symbiotic. It has been obvious for years to anthropologists that weapons make dominance a chancy business, and thus require a leader to lead more by persuasion than by coercion. The !Kung people of South Africa have a habit of saying, during an argument: ‘We are none of us big and others small; we are all men and can fight. I am going to get my arrows.’ In his stories of Prohibition-era New York, Damon Runyon’s slang for guns was ‘equalizers’.

We are irredeemably tribal creatures. The neighbouring or rival group, however defined, is automatically an enemy. Argentinians and Chileans hate each other because there is nobody else nearby to hate.

This grandmother of all football riots illustrates that the power of xenophobic group loyalty in the human species is every bit as potent as it is in chimpanzees. And yet we also bring to xenophobia a crucial feature of dolphin society. We form second-order alliances.

But they take for granted certain things about human nature that we need not, in particular our tribalism. My aim is to convince you to try to step out of your human skin and look back at our species with all its foibles. Then we notice that our politics need not be the way it is, for we need not be tribal at all. If we were truly like dolphins and lived in open societies, there would still be aggression, violence, coalition-building and politics, but the human world would be like a water-colour painting, not a mosaic of human populations. There would not be nationalism, borders, in-groups and out-groups, warfare. These are the consequences of tribal thinking, which itself is the consequence of our evolutionary heritage as coalition-building, troop-living apes.

CHAPTER NINE: The Source of War

A tribe including many members who, from possessing in high degree the spirit of patriotism, fidelity, obedience, courage and sympathy, were always ready to aid one another, and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection.

Competition between the groups is fiercer than between individual ants. Only when there are no enemy groups left do the individuals assert their selfishness against their co-queens. To put it in more human terms, an external enemy helps group cohesion. This is a thoroughly familiar idea

Maybe cooperation is such a feature of our society not because of close kinship, not because of reciprocity, not because of moral teaching, but because of ‘group selection’: cooperative groups thrive and selfish ones do not, so cooperative societies have survived at the expense of others. Natural selection has taken place not at the level of the individual but at the level of the band or tribe.

But what happens when something is good for the species but bad for the individual? What happens, in other words, in a prisoner’s dilemma? We know what happens. The individual’s interest comes first. Selfless groups would be perpetually undermined by the selfishness of their individuals.

Selfishness spreads like flu through any species or group that tries to exercise restraint on behalf of the larger group. Individual ambition always gets its way against collective restraint. And there is simply no good example, to this day, of an animal or plant that has been found to practise group selection unless in a clone or closely related family — except in the temporary and passing conditions of new-colony formation in the desert seedharvester ant. Bees risk their lives to defend the hive, not because they wish the hive itself to survive, but because they wish the genes they share with their many sisters in the hive to survive. Their courage is gene-selfish.

That exception is, of course, the human being. What makes human beings different is culture. Because of the human practice of passing on traditions, customs, knowledge and beliefs by direct infection from one person to another, there is a whole new kind of evolution going on in human beings — a competition not between genetically different individuals or groups, but between culturally different individuals or groups. One person may thrive at the expense of another not because he has better genes, but because he knows or believes something of practical value.

(This incidentally is one reason why genetic group selection does not work — the genes of the defeated individuals survive; indeed, in the case of women captured in war after the sack of an ancient city and taken as wives, the genes of the defeated individuals probably thrived and infiltrated the victorious group. But because the defeated individuals drop their culture and absorb that of the victors, cultural group selection can work.)

All we have identified in human beings is a powerful tendency to be groupish in the pursuit of individual goals, not evidence of putting groups before individuals. A mind that has been selected to gain the advantages of living in groups (conformism is an instance) is not the same as a mind that has evolved by group selection. Groupishness can enhance individual selection — but that is not group selection. The problem arises, according to John Hartung, because we are so instinctively groupish that we prefer to pretend — and perhaps even believe — that we are group-selected. In other words, people claim they are putting the interests of the group first and not their own interests, the better to disguise the fact that they only go along with the group when it suits them. The fact that people form emotional attachments to groups, even arbitrary ones, such as randomly selected school sports teams, does not prove group selection, but the reverse. It proves that people have a very sensitive awareness of where their individual interests lie — with which group. We are an extremely groupish species, but not a group-selected one. We are designed not to sacrifice ourselves for the group but to exploit the group for ourselves.

Christianity, it is true, teaches love to all people, not just fellow Christians. This seems to be largely an invention of St Paul’s, since Jesus frequently discriminated in the gospels between Jews and Gentiles, and made clear that his message was for Jews.

After all, as Sir Arthur Keith pointed out, Hitler perfected the double standard of in-group morality and out-group ferocity by calling his movement national socialism. Socialism stood for communitarianism within the tribe, nationalism for its vicious exterior. He needed no religious spur. But given that humankind has an instinct towards tribalism that millions of years of groupishness have fostered, religions have thrived to the extent that they stressed the community of the converted and the evil of the heathen. Hartung ends his essay on a bleak note, doubting that universal morality can be taught by religions steeped in such traditions, or that it can even be attained unless a war with another world unifies the whole planet.

If human beings are nice to each other only because of an inherent xenophobia learnt during millennia of lethal inter-group violence, then there is not much comfort here for moralists.

CHAPTER TEN: The Gains from Trade

The second lesson of the Yir Yoront story is that there is nothing modern about commerce.

Trade is the beneficent side of human groupishness. I have argued that human beings, along with chimpanzees, are unusual in their addiction to group territoriality and inter-group conflict. We segregate into territorial groups and the shared fate that we enjoy with other members of the group drives us into a mixture of xenophobia and cultural conformity, an instinctive subservience to the larger whole that partly explains our collaborative nature.

But there are remarkable similarities between the patterns of trade in both Stone Age peoples, including especially the association between trade and reciprocal feasting. Chagnon believes that it is the feasting that is, so to speak, the aim, and trade that is the excuse, because from the feasts comes the friendship that cements the alliance that is valuable in warfare. But whether trade is the means or the end hardly matters. The same lesson applies: trade is the precursor of politics, not the consequence.

Government, law, justice and politics are not only far more recently developed than trade, but they follow where trade leads. Indeed, just as this is true for hunter-gatherers, so it now appears to have been true for medieval merchants as well. Modern commercial law was invented and enforced not by governments, but by merchants themselves. Only later did governments try to take it over, and with mostly disastrous results.

By the twelfth century commercial middlemen were using the new concept of credit. This was a great improvement on barter, and on money, which had lost the uniformity and fungibility it had had in Roman times. Bankers had begun to emerge, together with mortgages, contracts, promissory notes and bills of exchange. All these were governed by merchant law, not government law. Governments had not even woken up to what was going on. An entirely private, voluntary and informal system of exchange had developed.

The lesson, for scientists, though, is crystal clear. Markets, exchanges and rules can develop before government or any other monopolist has defined their rules. They define their own rules, because they have been part of human nature for many millions of years.

Even if I am wrong, even if trade between groups came much later, at the brink of recorded history, its invention represents one of the very few moments in evolution when Homo sapiens stumbled on some competitive ecological advantage over other species that was truly unique. There simply is no other animal that exploits the law of comparative advantage between groups. Within groups, as we have seen, the division of labour is beautifully exploited by the ants, the mole rats, the Huia birds. But not between groups.

CHAPTER ELEVEN: Ecology as Religion

Unless forcibly reminded of nature’s cruelty, people tend to romanticize wildlife, seeing benevolence and overlooking viciousness. As George Williams has emphasized, crimes at least equivalent in their effects (if not their motives) to murder, rape, cannibalism, infanticide, deception, theft, torture and genocide are not just committed by animals, but are almost ways of life. Ground squirrels routinely eat baby ground squirrels; mallard drakes routinely drown ducks during gang rape; parasitic wasps routinely eat their victims alive from the inside; chimpanzees — our nearest relatives — routinely pursue gang warfare. Yet, as supposedly objective television programmes about nature repeatedly demonstrate, human beings just do not want to know these facts. They bowdlerize nature, desperately play up the slimmest of clues to animal virtue (dolphins saving drowning people, elephants mourning their dead), and clutch at straws suggesting that humankind somehow caused aberrant cruelty. When dolphins were recently found to be attacking porpoises off Scotland, animal ‘experts’ attributed this ‘aberrant behavior’ to pollution of some kind, an assertion for which they admitted they had no evidence of any kind. We eliminate the negative and sentimentalize the positive.

This is, of course, hypocrisy. Just as we wish other people to turn the other cheek when hurt, but seek revenge on behalf of close relatives and friends, just as we urge morality far more than we act it, so environmentalism is something we prefer to preach than to practise. Everybody, it seems, wants a new road for themselves, but less road-building. Everybody wants another car, but wishes there were fewer on the road. Everybody wants two kids, but lower population growth. The idea that native Americans had an environmental ethic that prevented their over-exploitation of nature is a recent invention of Westerners.

The devastation wrought by our indigenous and traditional ancestors as they extinguished their way across the planet during and after the last ice age is only now becoming clear. Coincident with the first certain arrival of people in North America, 11,500 years ago, seventy-three per cent of the large mammal genera quickly died out. Gone were giant bison, wild horse, short-faced bear, mammoth, mastodon, sabre-toothed cat, giant ground sloth and wild camel. By 8,000 years ago, eighty per cent of the large mammal genera in South America were also extinct — giant sloths, giant armadillos, giant guanacos, giant capybaras, anteaters the size of horses. This is known as the Pleistocene overkill.

History abounds with evidence that the limitations of technology or demand, rather than a culture of self-restraint, is what has kept tribal people from overexploiting their environment.

CHAPTER TWELVE: The Power of Property

The rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another; and another … But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein lies the tragedy. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons. Freedom in a commons brings ruin to all.

The problem is, Hardin was wrong about grazing commons. Medieval commons were not disastrous free-for-alls. They were carefully regulated communal property, just like the lobster fisheries of Maine. True, there were relatively few written rights and not many obvious rules about who could graze them or cut coppice-wood on them. To an outsider, they looked like a free-for-all. But try adding your cattle to the common herd and you would soon discover the unwritten rules.

In practice, an English medieval common was a complex spider’s web of jealously guarded property rights held under the supposedly benevolent umbrella of the lord of the manor, who owned the common but only on condition that he did not interfere with the rights of the commoners.

It is nonsense to argue that just because something is communally owned it must suffer the tragedy of the commons. Common property and open-access free-for-alls are very different things. The old pre-enclosure English commons as a genuinely egalitarian place open to all is a nostalgic myth. Hardin was apparently unaware of this, and what he wrote was based on theory, not fact.

Government is not the solution to tragedies of the commons. It is the prime cause of them.

So Ostrom’s conclusions are that communication alone can make a remarkable difference to people’s ability and willingness to exercise environmental restraint: indeed communication is more important than punishment. Covenants without swords work; swords without covenants do not. Take that, Hobbes! And so much for Hardin’s plea for coercion.

The key to solving common problems is the assertion of ownership — communal if necessary, individual if possible.

Evidence for the idea that people sustainably exploit only those things they can own comes from the fact that valuable living resources in tropical forests are generally treated with much more restraint if they do not move. Jared Diamond reports that New Guineans exhibit a conservation ethic only where individual rights are owned by individual people. A tree of a certain rare kind preferred for hollowing out as canoes belongs to he who finds it, and this rule is respected. The owner can therefore wait until he needs a new canoe before he fells it. Likewise, a tree used for display by certain birds of paradise is also privately owned by whoever finds it first. The owner has the sole right to shoot the birds for their prized, decorative plumes.

The difference between megapode nesting sites, beaver dams, bird-of-paradise trees and canoe trees on the one hand, and mammoths, tapir or herring on the other is that the former do not move. Property rights in the former are easily asserted, marked and defended. The thing that prevented our ancestors sustainably exploiting mammoths and elks was the fact that it was impossible to operate property rights in wild animals. These property rights need not be individual — they could be communal — but they were the key to ecological virtue.

Polluting companies adore regulation by government, because it protects them from civil suits and discourages new entrants to their business. They are terrified of environmental pressure from property rights asserted through the common law: Together trespass, nuisance and riparian rights have effectively empowered people to preserve or restore clean land, air and water — too effectively, apparently, for governments, which have worked assiduously to undermine property rights and the environmental protection they have fostered.

Private property is often the friend of conservation; government regulation is often the enemy. Yet such a conclusion enrages environmentalists, who almost to a man and woman blame Western traditions of private property and greed for the damage that is being done to the environment, and recommend government intervention as the solution.

Our minds have been built by selfish genes, but they have been built to be social, trustworthy and cooperative. That is the paradox this book has tried to explain.