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Ridley, Matt 1993 The Red Queen,
Penguin, London

Ridley, Matt 1996 The Origins of Virtue,
Penguin Viking ISBN 0-670-86357-2

A Review of Origins of Virtue - CK

The Red Queen is a brilliant essay on the ways in which the changing evolutionary environment in which we live is one of the most pervasive influences on our own evolution and one which, like the red queen of Lewis Carrol, requires us to keep running, just to keep standing still in terms of evolutionary adaption, relative to our predators, parasites, food-species and even our fellow individuals. The central expression of this phenomenon is the variety induced by sex and the role sex thus plays in evolution.

Ridley first traces the influences at work on these ideas. Darwin himself noted that sexuality provided a method of selective breeding - adaptive sexual selection. This is in a sense complementary to natural selection from the external environment. Weismann first noted the continuity of the germ line meant evolution was a descent from sex cell to sex cell - making the organism an effective side shoot from the evolutionary process. Richard Dawkins carried this idea to its logical conclusion, shifting the emphasis of selection from the organism to the gene itself .

Whatever the moral ironies of the metaphor of the "selfish gene", one has to acknowledge that in a fundamental sense, it is honest - a gene is adapted to its own survival and will continue to evolve in ways which further its own survival whether by cooperation or competition with its co-travellers. However the virtue of this approach is clearly not to suggest that we are at root just a bunch of selfish genes run riot, but lies in the rich descriptive power it provides of the many and varied adaptive functional relationships which occur in the genome.

This revolution of outlook about evolution is part of a wider swing from emphasis on species to the individual as the instrument of natural selection. The early evolutionists coined a utopian vision of evolution in which evolution was adapted for the welfare of the species - something called group selection. However the actual mechanics of descent pass in every case through individuals.

Weismann himself noted that sex was not merely to reproduce and suggested that it was "a source of individual variability furnishing material for the operation of natural selection". Fisher and Muller following him documented the way sexuality made it possible to combine advantageous mutations in different individuals - broadly-speaking sexual species could 'out-evolve' non-sexual ones.

Nicholas Humphrey added in the idea that the fellow members of our own species are our closest and most complex competitors, making selection within species more important than selection between species. While species and individual interests may coincide, they may also differ leading to potential conflict. In rebuttal of the group-selectionist arguments, George Williams then laid out in "Adaption and Natural Selection" just how 'collective effects could flow from the actions of self-interested individuals'. This position was echoed in Darwin's emphasis on the primacy of the struggle between individuals rather than groups.

With the rise of the individual-selection viewpoint, it was realized that "no creature could ever evolve the ability to help its species at the expense of itself. Only when the two interests coincided would it act selflessly." Hamilton then broadened the selfish horizon with the concept of kin-selection - weighting the partial genetic identities of your relatives into the selection equation. Acting to preserve the genes of your relative is preserving a proportion of your own genes as well. This idea was extended further by Trivers to reciprocal altruism - the capacity to futher the interests of another who likewise enhances one's own (or one's relative) chances of survival.

Once this emphasis went to the individual, the original concepts of the role of sex in evolution, which were essentially group-selection in basis collapsed. John Maynard Smith pointed out that sex had to be at least twice as good at producing offspring as a non-sexual 'budding' species, because it only conserved half of the genes of either parent. This would mean that a non-sexual variant would outbreed a sexual variety 2:1 and cause it to go extinct long before it could ever gain from accelerated evolution.

In the 1970s a variety of approaches were mounted to try to explain why sex was almost universally pervasive in the metazoan world. This said, there do remain a variety of non-sexual or only partially sexual species spreading across many kinds of organism. Snails, Aphids, Dandelions and rotifers exist in non-sexual forms, which in rotifers, from mutational divergence studies of non-coding DNA appear to have last has sex around 80 million years ago. In many of the other cases there are cryptic sexual exchanges, sometimes with related species, at intervals.

Molecular biologists noted that sexual recombination depended on the DNA repair machinery to function and suggested that sex served a repair function. Damage to recombination does cause sensitivity to mutatenic agents, and duplicate chromosomes in contrast reduce it, but this does not explain out-crossing - why it is advantageous to cross with different DNA. Diploidy or multi-ploidy can serve this function as well and indeed in some higher plants appears to do so.

A different kind of mechanism is proposed by Muller's ratchet and it's reverse. The idea here is that errors accumulate in non-sexual species like a ratchet, but can be eliminated when only half your genes are transmitted in sexual fertilization. Bell showed this depended critically on population and genome sizes - large genomes and small populations required more sex. Kondrashov extended this idea to a reverse ratchet - those offspring with fewer defects survive, so sex also acts to eliminate defects. This may apply particularly to transposable genetic elements which insert themselves into sections of DNA and cause major changes. To act this way there has to be an average of one mutation per generation. Current estimeates are at the margin. Kondrashov also pointed out that sex may be necessary beacuse the alternative - proof-reading has a law of diminishing returns on the investment at very low error rates.

A variety of ecological theories have also been advanced to explain sex. George Williams has noted that many species which have both sexual and asexual phases use their sexual phase to reporoduce themselves over greater distances - for example flying aphids are sexual and non-flying ones parthenogenetic. Sex then becomes more necessary so that new varieties are created to deal with differing circumstances, often at low survival rates when only the optimal few succeed. However detailed field studies do not show ecological uncertainty correlating with sexuality. Bell noted "it seems to utterly fail the test of comparative analysis".

In Darwin's Origin of Species he finsihed with the passage: "It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing in the bushes with various insects flitting about, and with worms crawling through the damp earth, and to reflect on these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting upon us." The Tangled bank has become a metaphor to describe the idea that sexual variety is necessary to enable individual organisms to adapt to the variety of cirucmstances they find themselves in in a complex ecosystemic environment. However studies of the frequency of crossing-over show that this is not at all dependent on how many young an organism has, which should correlate with the variety needed to ensure survival, but rather with the life-span of the organism. A mouse has three and a human thirty. It is also in conflict with the relatively high degree of conservation of phenotype in sexual fossil species.

The Red Queen poses a different type of complexity account, which better fits many of the dynamic empirical facts and gives a very powerful explanation of the precise role of sex in its wide-spread occurrence in metazoa. The idea is that sexuality evolved from an immediate potent advantage that results from confounding parasites and predators because of genomic changes that result from sexual recombination.

We may find it hard to accept that we are evolving to evade our parasites, but we nevertheless acknowledge that disease of all infectious types is a principal cause of death, even in the age of modern technology. AIDS, influenza and malaria illustrate three key examples. Sexuality is shared by all branches of the metaphyta (plants animals and fungi) and penetrates many of the protoctista. Likewise the qualitative nature of the immune system is shared by vertebrates and invertebrates from coelenterates through to homo sapiens. Field investigations of parasites on various species does demonstrate an advantage in this respect to sexual organisms.

A basic feature of both immune system genes and the histocompatability genes that idiotype each individuals tissue in relation to foreign cells is the need for a large library of variant genes. A single mammal contains over 100 different histocompatability genes. Sex acts as an agent to promote the diversity required to evolve such libraries. It also changes them each generation in a way which makes it difficult for pathogens to adapt through more than one generation of host or even to decode the histocompatibility profile and hence use it to evade the immune system by masking as home tissue. Sex thus also acts as a powerful first-generation advantage simply because the descendents of each individual are idiotypically and immunity-wise different. The adaption made possibly by many generations of parasite are then lost on the host offspring. This provides a basic red-queen mechanism in which parasites are perpetually adapting to their hosts while sexual recombination is acting to evade such adaption.

Far from being an ultra-Darwinist mechanistic interpretation, such ideas represent a close genetic equivalent to the chaotic population dynamics seen in ecosystem populations. They mean that both the genetic makeup and predator-parasite-prey dynamics are in ever-changing feedback. A variety of computer models including Tierra and other artificial life simulations demonstrate such ecosystemic-genetic interactions and their mutational evolution.

Genetic Mutiny and Gender

The nature of bacterial transposons and the sexual pilii that infrequently join bacteria sexually and transfer genes through a tube, emphasize the point that sex is often intiatied for the specific benefit of sexual genes. Viruses also fall into this category. The myth of the "selfish gene" has been abundantly documented in the case of a variety of transposable genetic elements that can replicate in the genome after outcrossing and cause infertility. Of course, when we come to consider the conventional genes of an organism, these competitive forces are substantially held in check by the feedbacks required between functional genes to ensure the survival of the organism.

One great value of Dawkins' emphasis on the gene is that it illustrates a variety of ways in which genes can interact. Some species have killer genes that for example kill all sperms containing the other allele to the killer - called meiotic drive genes. Such genes are rare both because they incite reverse adaption and possibly also because sexual crossing-over can act to scramble the specificity of such killer genes by swapping neighbouring DNA used in recognition of self from opposite.

Such genetic competition is believed to underly the actual breaking of 'gender' between a large enveloping egg which subdivides to form the embryo and the sperm which contributes only nuclear chromosomes. This is in a sense a selfish strategy for the sperm becauuse of its lower investment, but it is apparently triggered by the competition between the very endosymbionts which form the organelles of respiration and photosynthesis. It turns out that when Chamlydomonas fuses plus and minus strains the plus strain chloroplasts only survive after a war of attrition that destroys 95% of them.

Fertilization by fusion always involves the destruction of the organelles of one gender. Thus both to avoid parasites and to avoid frank competition, during fertilization of an ovum by a sperm, organelles are digested or left behind at the membrane, leaving only the nuclear DNA. In effect the egg has inherited the killer status in terms of male organelles. Cytoplasmic inheritance thus passes exclusively through the 'killer sex'. As an alternative in conjugation, a narrow tube is used which can only pass DNA.

Ridley offers a just-so story for why animals are not hermaphrodites in the form of killer genes in organelles which try to destroy their male parts because these do not transmit cytoplasmic DNA. Maise and tobacco both have opposed pairs of such killer genes with cytoplasmic activators and specific nuclear repressors, which have been manipulated by humanity to give male sterile strains of maise which can be selectively hybridized. It is then assumed that the dynamic in animals has broadly been resolved so that the male-killer genes have pushed the equilibrium completely away from hermaphrodites by reducing the presence of sperms to such a small minority that malesness becomes a rare and hence advantageous attribute reinforcing the emergence of pure polarised male and female types.

Such male-killer genes do exist in various animals, including thirty species of insects, notably if and only if the young in a brood are in competition. Such male-killing genes are cytoplasmic, but in bacteria living inside the insect's cells. In wasps, where the male is an unfertilized haploid, males are turned female, making the wasp parthenogenic for as many generations as infection persists. There is even a case of a human family which was recorded in the 1940s as having seventy-two particularly fecund female offspring in succession without one male, in a manner wich suggested a feminizing cytoplasmic gene may have been at work.

Humans of course use XY chromosomes to determine the sex of the adult, but in some fish, shrimps and reptiles, sex is determined by the temperature of hatching. With some fish, such as the blue-headed wrasse, the largest female switches sex to become male. In bees and wasps the unfertilized eggs become haploid males so the mother is able to select the sex of her offspring. She can then bias the ratio to balance the differing reproductive potentiality of each gender.

Environmental factors may also influence the sex ratio of offspring in mammals, despite their XY sexuality. Males are subject to much greater diversity of reproductive potential than females because they can readily access many females, but may get access to none. By contrast all fertile females are comparably capable of reproduction. Trivers and Willard proposed that the offspring of high-condition mothers are more liable to be successful and thus take advantage of the increased reproductive potential of a dominant or desirable male. Sex ratios in highly fed animals can reach 1.4 males to each female. Sexual bias in animals may be partly a result of a process of selective abortion, even sometimes of whole high-female litters.

This effect has been confirmed in several mammal species but the picture became more complicated. It turned out to be more the mothers rank in the social group which influenced the sex of their offspring. If sons were exchanged between family groups but daughters remained to possibly inherit their mother's status, as in the case of baboons, high ranking females would have more daughters.

Now unlike most monkeys, apes including bonobos and chimps are patrilocal in the sense that the females, rather than the males, move between family groups. There are indications that human society may have been more commonly patrilocal. People have noticed that 60% of the children of US presidents are boys. Valerie Grant also discovered that mothers who subsequently had daughters rated 1.35 on a psychological dominance scale, but those who later had sons rated 2.26 - a highly significant difference. It has been suggested that hormone levels may be a feedback factor between these two. Gonadotropin in the mother is female biased and testosterone in the father male-biased. In studies of some feudal societes Laura Betzig and Sarah Hrdy have noted bias towards more males among elite class groups, while the peasantry have a compensating slight bias towards more daughters. In fact the requirement for a 50-50 ratio of sons and daughters stemming from the collectively equal reproductive potential of each sex as a whole will lead to such compensation. Since the male inherits his rank, the female has a chance to marry up, but because she moves cannot carry her rank and family connections. The dowry can thus be thought of as the price paid by the female to enter the social rank of the male - again fitting the Trivers-Willard model.

It is worth noting in passing that many anthropologists have hypothesized the idea of trading women as possessions as a founding process in human society and used this to advance a linkage between females moving between family groups and patriarchal power and possession. However it is clear from Bonobo society that the females are socially ascendant in a patrilocal family grouping. Thus a bias towards male offspring among elites in human society does not demonstrate patriarchal dominance over evolutionary timescales. In early human gatherer-hunter societies, cooperation among the females during gathering could likewise occur in a patrilocal context. The egalitarian nature of the !Kung is consistent with this picture, suggesting the hierarchial superstructure of patriarchal hegemony is more recent.

Such beliefs in elite male desirability also permeate however into the social customs of whole societies. Chinese, deprived of a chance to have more than one child killed more than 250,000 baby girls between 1979 and 1984. In some age groups in China there are 122 boys for every 100 girls, consistent with 17% of all girls being killed at birth. In one recent study of clinics in Bombay, of 8,000 abortions, 7,997 were of female foetuses, leading to a move to ban ultra-sound for sexual differentiation. In one hospital 96% of mothers who were told they had a daughter aborted, while 100% with sons carried to term. Such a bias towards males is harmful to the societies which allow such processes, because they lead to further male domination and competitive violence.

The Peacock's Tale

In sexual selection there is an inevitable dissonance between female selection and male competition. Tim Halliday as late as 1983 stated "where female choice has been described, it plays an ancilliary, and probably less significant role than competition between males." However by the mid-1980s the evidence, such as that of Moller and of Hoglund had begun to accumulate that in many species , females had a large say in the matter of their mating partner, and a more significant one than inter-male competition, even to the extent of preferring long feathers which are a survival risk to he male.

An explanation for the excess of many male birds, such as the peacocks tail, is so-called runaway selection: once the females establish a preference for a certain trait it becomes disadvantageous for any female to select for less such preference because her offspring will not be able to compete in the eyes of the female group. Such selection applies to both polygamous and monogamous species. Both genders are making a choice in such courtships.

There are important lessons to be learned from such mating engagements. Females who depend on their partners to help them rear young are less choosy than females who do all the rearing and are thus free to spend all their time deciding on which male has the best genes. It is in species with such independent females where we find the most elaborate male displays and here the females all seek the most desirable males. A male sage grouse may mate 30 times in a morning. However such a process of rapid dissemination of only a few genes allowed runaway could lead to genetic uniformity. This is a process known as the lek paradox after the breeding markets of these male display birds.

There are two prevalent theories concerning sexual selection, the idea that it results in sexy males and the idea that the display indirectly chooses good genes. The first gives arbitrary results and the second improved 'fitness'. Computer simulations of the former do show an equilibrium between male survival disadvantage and reproductive advantage at finding a mate. These equilibria remain when risks to the female in delaying the choice through lost breeding opportunity or risk from predators and the mutational bias away from an elaborate selected state such as a peacock's tail are included. They are also supported by the frank incidence of fashion among female animals of several species, who tend to agregate with and follow the mating choices of other females.

Zahlavi was first to point out that the very encumberance such males endured was an indication of fitness, because to survive with it required additional resources. This in turn gave an explanation why features which at the surface seem disadvantageous were also consistent with a 'good genes' approach.

Hamilton and Zuk in 1982 then proceeded to introduce a red queen explanation for the lek paradox. The idea is that the display indicates healthy resistance to parasites. The females thus inherit good resistance genes, but adaption by the parasites may then lead to a genetically-different male the next generation being more resistant. The mutational adaption of the parasites thus indirectly ensures genetic diversity will be maintained among the host. Field studies do support such a relation between parasites and display. Symmetry is a condition-dependent trait which is seen to be advantageous in swallows tails. It appears that both theories account for some of the cases.

At this point the question of dishonesty arises. Some attributes such as a cock's comb are good indications of fitness, but a female has a certain cost in going to greater effort to establish her partner's credentials are trustworthy, so sometimes deception is worth putting up with and is thus successful. A novel theory for the hour glass physique is Bobbi Low's idea that the breast and hip fattening in reproductive females is a form of deception that they are good child-bearing high milk-bearing fecund females, and that hour-glass waists are a token of an unencumbered uterus. However such fat is also associated with better survival value under gatherer hardships. Honesty and deception are not inconsistent.

Polygamy and the Nature of Men

Men are theoretically capable of reproducing in virtually every copulation. Indeed in large harems, the fertility of the females was carefully arranged to coincide with coitus in this way.

We can learn (1) by studying modern people, overtly monogamous (2) history where we find large harems, (3) simple societies with stone-age technologies, where we find an intermediate condition of polygamy even in overt monogamies, (4) apes where our testicles are not big enough for institutional promiscuity nor males bigger enough then the females for institutional harems in animal terms, (5) other highly-social animals, monogamy plagued by adultery.

We form lasting bonds between sexual partners even within polygamy and we are not poly-androus (except for the exceptional brother marriage of Tibet). Males are generally the solicitors of sexual union. The male has nothing biological to lose like the female and everything to gain, so this is logical. The underlying wide variance in male reproductive success also supports active partner-seeking. In species where the male does the child-rearing the female, having a lower investment, does become the dominantly-active solicitor.

Infidelity and prostitution are special cases of polygyny. The very-high indicence of male homosexual promiscuity indicates the nature of unrestrained male tendencies. The efficacy of polygamy to a female depends on how the wealth of males is distributed. Being a subsequent wife of a highly-resourced man provides better for offspring than the monogamous partner of a pauper, however this interaction has to take into account whether the females will accept the situation and may involve the first wife retaining compensating benefits which give her greater resources, even a large share of her husband's estate. Anti-polygamy laws act principally to protect men by ensuring an equal distribution of women to men. The game theory supports the idea that female choice plays a significant role in the polygamy threshold.

The mating system of mammals depends on its socio-ecology - how the females distribute themselves. The greater the extent to which the females gather in groups in their foraging habits the greater the tendency to polygyny, although the recent history of a species is influential on its current dynamic.

This brings us to consider the food habits of humans and in particular the female gatherers. Humans probably practised female exogamy like other apes, making it difficult for females to build coalitions of relatives and retain status of group hierarchies. When the division occurred into Australopithecus robustus and Homo erectus, possibly as a result of prolonged dry seasons and famine, Homo also took up meat-eating. There appears to have been a sexual division of labour between hunting men and gathering women, something unique to humans and a few birds of prey. The human form became more juvenile - neotonic - allowing for brain expansion, just as human children today have a higher brain to body weight than adults.

Modern hunter-gatherer societies show great ecological and social variation, indicating such early societies were probably adaptible and dynamic in their form, depending on cirucumstance and opportunity. These probably also invloved fluctuations in sexual habit between polygamy and monogamy. They may have also facilitated good judgement of character and limitations on deception, because people remained in relatively close association and got to know one another well.

Modern hunter-gatherer societies show a spectrum of relationship patterns in which monogamy predominates, adultery is frequent and perhaps 15% of men are in polygamous marriages. Because hunting is only intermittently successful, it does not provide the regular riches required for established polygamy, and is often engaged in a spirit of reciprocal altruism through sharing the proceeds. The onset of polygamy in human society coincides with the invention of agriculture, frequently resulting in harems of up to 100 or more women. Larger civilizations then led to harems of thousands of young women, leaving many men unpartnered or slaves.

It is difficult to determine the extent to which male group coalitions influenced human societies and monopolized females. Laura Betzig found that in historical societies male power was virtually always translated into reproductive success with similar measures to ensure their concubines were in as fertile state as possible, including wet-nurses to enable mothers to rapidly re-enter ovulation. The same pattern occurred in Christian castles and monastries, which included frank gynoeciums, leaving the fields full of male peasants.

Monogamy and the Nature of Women

Sarah Hrdy brought attention to the fact that female primates adopt a variety of strategies to avoid the very significant threat of infanticide, which is common in primates, carnivores and rodents. They may either be faithful to their harem leader in gorillas or promiscuous with an entire related coalition as in apes to avoid the likelihood of infanticide. Human step-children are sixty-five time mores likely to be killed that true children, but not in early infancy. Bonobo females are even more promiscuous. A young female bonobo who arrives at a tree where others of the species are feeding will first mate with each of the males in turn - including the adolescents - and only then get on with eating. Gorillas mate roughly 10 times per pregnancy chimps 1000 but bonobo 5000. Matt wryly comments the best thing for a male bonobo to do is eat his greens, have a good night's sleep and prepare for a long day of fornication.

Do females seek a husband and then look for a superior lover? Chimps have big testicles because there is a lot of sperm competition in their promiscuous lifestyle. Gorillas have very small ones because there is no competition. Humans are intermediate, consistent with intermittent 'affairs' rather than full-blown promiscuity. They also have 'kamakaze' sperm which block the vaginal canal indicating protective sperm competition.

In birds, genetic testing reaveals that even in monogamous species up to 40% of the young can be 'bastards', suggesting that female birds routinely attempt to gain both a reliable mate and the best sperm available, again consistent with male garishness and continuing courting songs even after mating is accomplished. In swallows females prefer desirable partnered males as lovers. The opportunity is provided by colonial nesting and furthers both the male and female reproductive interests.

We then consider the sperm retention of female orgasm, occuring simultaneously or subsequent to male ejaculation and the fact that unfaithful women frequently mate close to ovulation and have a predominance of retentive orgasms. All in all, even if an unfaithful woman has sex twice as often with her husband, she is still more likely to conceive by her lover. Genetic tests in several English cities confirmed that up to 20% of children are not the offspring of their ostensible fathers. Men also make larger ejaculates when they are away from their wives during the day again indicating sperm competition.

Kim Hill studying the Ache in whom gifts of meat by men are a traditional token for an offer of adultery, found that female infidely was not confined to the wives of low-ranking husbands and may represent a form of insurance against instability in their existing relationships. "Hill and others believe that adultery has been much under-emphasized as an influence in the evolution of the human mating system". The realtive importance of' 'adultery' in human society is reinforced by the relative rarity of polygamy on a population basis within such societies.

The 'grape vine' is a typical social means in human society of mate guarding, something practiced very carefully by birds. Wrangham, who studied African pygmies and the role of gossip speculates that the sexual division of labour, the institution of child-rearing marriages and the invention of language (without which the grape vine is impossible), three of the most fundamental human characteristics that we share with no other ape, all depended on one another.

The concealed ovulation - sometimes called 'reproductive inscrutability' may thus have preceded and initiated language. Desmond Morris called humanity the 'sexiest primate alive' (but that was before anyone studied bonobos). Concealed ovulation is shared with the orang-utan, some monkeys and nearly all birds.

Nancy Burley has suggested it arose because females who knew they were ovulating refused to coupulate to avoid the hardships of pregnancy and died out. Others speculate that it was a way of ensuring partners do not desert their young or that it was to prevent fathers knowing who their young were or were not thus avoiding male infanticide. One theory says if men do not know when their partners are fertile, they have to stick around more to have a good chance, and thus end up helping with the child-rearing. Another says frankly that concealed ovulation is a means for the female to be able to have choice of her mate and to keep it secret. This both prevents infanticide, as Sarah Hrdy has suggested, and also gives her evolutionary freedom of decision.

Since concealed ovulation empowers both the faithful wife, by keeping the husband around, and the unfaithful wife, by enabling infidelity, it begets female competition. Several studies in birds confirm the fact that competition between females is a substantial factor inhibiting polygamy, which would, in its absence, be as successful at rearing young as the monogamous state. Ridley contends that in humans, just like sparrows, "adultery is common. It is commonest between high-ranking males and females of all ranks. To prevent it males try to guard their wives, are extremely violent towards their wives' lovers and coupulate with their wives frequently, not just while they are fertile." Human sexual privacy obviously acts to optimize covert infidelity. The female has thus kept one step ahead of the male in evolution.

Ridley continues "The use of veils, chaperones, purdah, female circumcision and chastity belts all bear witness to a widespread male fear of being cuckolded and a widespread suspicion that wives, as well as their potential lovers, are the ones to distrust (why else circumcise them?) . Margot Wilson and Martin Daly see jealousy as fitting an evolutionary explanation universal to human society in which "there is socially recognised marriage, adultery is a property violation, the valuation of female chastity, the equation of 'protection' of women with protection from sexual contact and the special potency of infidelity as a provocation to violence. In short, in every age and in every place, men behave as if they owned their wives' vaginas." They note that love and jealousy are two sides of the same coin - the sexual propriety claim. The absence of jealousy can even be the cause of insecurity. Husbands of rape victims are sometimes resentful if their wives do not show evidence of (violent) resistance, just as the ancient Jewish law describes in stoning for adultery. Cuckoldry is asymmetric, harming the male's interests much more than male infidelity does the female, unless it leads to desertion and loss of resources.

Although this double standard is often described as a prime example of the sexism of society, its evolutionary origins tell another story - as emphasized in all notions of pollution - alien offspring. Contrasting with this is the enormous potential to be gained by a male "Matty Groves" who succeeds in covertly fertilizing the wife of a high nobleman because of the increased reproductive opportunity his potential sons will gain. Ridley notes a correspondence between this and the ideal of courtly love - the Sir Lancelot phenomenon.

Sexing the Mind

Matt now expands to the level of socio-biology of the brain and mind and discusses similar issues to Doreen Kimura's article. He stresses that nature and nurture are complementary rather than opposites and that both can play a simultaneous role in influencing our minds and decisions. The human brain/mind is extremely adaptible and individuals very variable. He then points out obvious differences which could be illustrated by 'boys love cars, girls love dolls' - 'men love map reading and women read novels'. Men like career adventure while women make good home builders. He follows with a discussion of testosterone in masculinizing the brain, firstly in a short natal burst and then in adolescence, and its association with violence and competition. This ironically causes girls to first educationally leap ahead with better verbal and social skills. Boys only catch up by adolescence. He notes the greater lateralization of the male brain and larger corpus callousum connecting the hemispheres in the female.

He notes men as aspiring to being practical, shrewd, assertive, dominating, competitive, critical and self-controlled and women loving, affectionate, impulsive, sympathetic, and generous. The men's language is public, domineering, competitive, status-obsessed, attention-seeking, factual and designed to reveal knowledge and skill, while womens is cooperative, rapport-establishing, reassuring, empathic, egalitarian, and meandering (talk for talk). He notes the preference of women for a mate who is high-ranking and resourceful - rich and powerful if you like - while men want young attractive healthy women. Men want a woman who can independently deliver and care for an offspring biologically, women want good genes which show evidence of masterfulness and resourcefullness, because they are making a prime personal investment in getting pregnant.

Buss who has estimated cross-culturally mens interest in women is somewhat in a sparring relationship with Sarah Hrdy over these two complementary views (The New Social Darwinists Scientific American Oct 1995 151 John Horgan). Notice John Horgan's patriarchal dig in the first sentence " 'Men just love coming up with scenarios for female breasts because they love looking at them' Hrdy snaps. She complains that far too much time has been expended on 'preference' studies like Buss's; sexual behavior is often more complex and calculated than such surveys suggest - for example male jealousy may often be irrational, but the female preference for mates with money makes perfect sense today, given that womens economic opportunities are limited in most societies - that evolutionary psychologists must move beyond their 'discovery' that men like pretty girls and women like wealthy men."

Ridly in like style launches into a very telling critique of feminism noting that his supposition is at face value feminist because it confims that women are sociable and nurturing, positive qualities in a conflict-ridden world, but then asserting that feminists are having their cake and eating it too by assuming they can both be as effective managers as men (sexual equality) while asserting that they would handle their power more cooperatively (sexual difference).

This argument is a stunning attempt by a male to draw a line in the sand to protect his gender through stealth. Firstly it is quite invalid, since some women are very good managers and women are generally more socially aware, careful choosers and nurtuing in their outlook towards the world. But Matt doesn't follow this issue - he claims this is "not egalitarian". He adds "They begin fron the assumption that women are by nature different beings. If women ran the world there would be no war. When women run companies, cooperation, not competition is the watchword". This is fine, firstly it is true they can manage well and secondly it is true that many women aspire to cooperative relationship. Many hunter-gatherer societies such as the !Kung are specifically noted for their egalitarian nature, both in sexual and class respects. Whence then the conclusion that acknowleging sexual complementation is not egalitarian? Matt defensively calls these "all explicit and firm assertions of sexism". This is an unfair charge, because equality of opportunity is advocated simply by individual variation and avoiding discrimination. Acknowledged differences in sexual socio-biology are not sexist they are natural.

It is natural for a man to seek more partners and be more jealous over paternity uncertainty, but it is sexism for men to demand female circumcision or stoning for adultery. It is not sexism for females to point out to a male-dominated society driven towards ecocrisis that the gender imbalances of political power are damaging to the world and that good would come from and greater feminine say in the world's future. In this sense the feminist thesis is true and in no way sexist.

Matt argues this preference in men is evidence of lifetime marriages, but since men often fantasize and sometimes have up to 1000 partners it is hard to imagine this being true in practice. Even if it were true, an old man doesn't need a young woman for life. Helen Fisher on the other hand quotes a mode of four years for marriage based on modal statistics and the idea this is a point by which the child has become relatively independent.

The Intellectual Chess Game

A basic question similar to nature and nurture is instinct versus adaptability. Leda Cosmides and John Tooby in "The Adapted Mind" make the case that a variety of specialized skills underly our adaptability, thus being an ecosystem of instincts which provide for correspondences as basic as the generality and semantic nature of language generation - of arbitary sounds with objects like 'cup', making the tabula rasa - culturally derived view of the mind an exterme lacking evolutionary depth. The Adapted Mind extends this argument to a variety of human cognitive skills, including reading characeter and emotion from facial and bodily expression and sexual attitudes.

The myth of man the toolmaker is then discounted because toolmaking remains very primitive long after man's brain has become very large, only becoming suddenly diverse with homo sapiens. Even by comparison with ape tool use, man, until recently, has not been so unusual. By contrast, !Kung "possess an enormous accumulation of local lore - when and where to hunt for each kind of animal, how to read a spoor, where to find each kind of plant food, which kind of food is available after rains, which things are poisonous and which are medicinal. Of the !Kung Melvin Konner wrote 'Their knowledge of wild plants and animals is deep and thorough enough to astonish and inform professional botanists and zoologists'."

In what has become the Machiavalian theory it is the social complexities of other humans and their dealings which forever presented new and dissonant situations, like living chess pieces with innovative and capriciously changing rules of engagement. The fact that he developed this theory after studying the !Kung attests to its plausibility. "After two years with the San, I came to think of the Pleistocene epoch of human history (the three million years during which we evolved) as one interminable marathon encounter group" - noting charged atmpospheres of frank expressions of feeling and contention running around the camp fire from dusk to dawn. This raises the thorny issue of social cheating and the idea that much of human cognition is devoted to developing models of social contracts, as ingeniously tested by Cosmides and Gigerenzer with counter-intuitive logic tests which are well-recognised only when they represent social contracts and supported by the fact that that Trivers' reciprocal altruism rewards both cooperation and cheating, so humans have evolved to detect it. We often apply tit-for-tat to deceivers - an almost invincible strategy. The difficulty with this theory is that all ape societies do the same - it is in no way unique to humans.

Geoffrey Miller returns to the sexual motif: "I suggest that the neocortex is not primarily or exclusively a device for tool-making, bipedal walking, fire-using, warfare, hunting, gathering or avoiding savannah predators. None of these postulated functions alone can explain its explosive developmentin our lineage and not in any other closely-related species ... The neocortex is largely a courtship device to attract and retains sexual mates: its specific evolutionary function is to stimulate and entertain other people, and to assess the stimulation attempts of others. ... Just as the peahen is satisfied with nothing less than a visually-brilliant display of peacock plumage, I postulate that homonid males and females became satisfied with nothing less than psychologically brilliant, fascinating, articulate, entertaining companions" - the cultural equivalent of runaway sexual selection - no one can afford to select for anything else and survive.

Matt finishes off with a theory which would make Buss smile and displease Sarah Hrdy. He suggests that this vagrant male selection for young pretty women selects for neotony - delayed development that enables the human brain to grow much bigger before it stops growing in relation to the body. Christopher Badcock has countered with a comparable theory of female selection of younger men. An interesting point here is that the female is the more neotonous of the two sexes, so once again the female is one step ahead in evolution.

Evolutionary Psychology

There is an important distinction between behavioral genetics in which genes are believed to directly influence behavior and evolutionary psychology, which concentrates on influences on societies rather than individuals and allows for individual variation and the adaptability of each individual mind and its ability to take account of the consequences of its actions. Margo Wilson and Martin Daly have discovered children younger than two are 60 times more likely to be killed by a step parent - almost always a stepfather - than a by natural parent. However they refuse to take either side in legal disputes centered on genetic predispositon to a crime and stress that individual variations in male violence are just as likely to be the result of environmental factors. Evolutionary psychology seeks in effect 'human nature' in general.

"First evolutionary psychologists are not so much interested in genetic differences whether among individuals or groups. The object of the study is rather, 'species typical mental adaptions' - also known as 'human nature'. A basic tennet of evolutionary psychologists is that people everywhere have fundamentally the same minds. A second tennet of evolutionary psychologists is respect for the power of the environment. The human mind they say has been designed to adjust to the social circumstances. ... It is belief in the power of the environment - family millieu, cultural circumstance - that allows evolutionary psychologists to see great variation in human behavior without reflexively concluding that the explanation lies in genetic variation."

And one result of this outlook is that inner-city violence shouldn't be labelled a pathology. " 'Violence is abhorrent ... violence is so aversive that even witnessing an instance can be literally sickening ... There is thus but a short leap to the metaphorical characterization of violence itself as a sort of sickness or dysfunction' .. But they insisted ... violence is eminently functional ... From an evolutionary point of view, the leading cause of violence is maleness 'Men have evolved the morphological, physiological and psychological means to be effective users of violence'. During evolution, men have competed over the scarce genetic resource of women - as always with natural selection, we are left with the genes of the winners - in this case genes inclining males toward fierce combat."

This contrasts significantly with the behavioral Darwinist view, which may cite low serotonin, high testosterone or other abnormalities such as the family which had a deficiency of monoamine oxidase leading to behavioral dysfunction. For identical twins, the probability of both being imprisoned if one is is 50%. With non-identical twins it is 20%. It is very important for society to realize all but the most extreme cases of genetic condition leave individuals able to be aware of the consequences of their actions and to be both adaptable and accountable. This is the basis of both individual freedom and the law. However evolutionary psychology is in many ways a group-selectionist position. Since the evidence for individual selection is strong, individual differences also need to be considered.

Ridley, Matt 1996 The Origins of Virtue,
Penguin Viking ISBN 0-670-86357-2

In the Origins of Virtue, Matt Ridley continues the sociobiological theme of theme of the Red Queen into the area of what causes virtue, moral sentiment and 'social altruism' given an organism which at the genetic level might appear to be a bundle of selfish genes. Pivotal to this idea is the common role of emotion.

The earlier chapters spend a great deal of time discussing reciprocity and the gatherer-hunter division of labour and the idea that social staus of the male and his sexual opportunities were mediated through exchange of meat.

Ridley orbits around the idea of sex for meat, although this belies the complexity of human sexual favoritism, the concealed estrus of the female and the privacy of human sexual activity by comparison with the public displays of food-sharing generosity and the very different food exchanges in bonobos for sex, where both sex and food are public.

Ridley casts moral sentiments in the practical light of reciprocal exchange and cites the Wason test of Leda Cosmides and John Tooby as portraying the deep role detecting cheating has in maintaining commitment and transactional 'trust' in social groups. The great sensitivity of humans to this type of test tends to emphasize how sophisticated our social sense of long-term commitment in the shifting interplay of human liaisons is.

Ridley sees emotions as a common currency of declaring commitment and revealing sufficient about our personal situations to facilitate a pragmatic degree of cooperation socially, which is conducive to a pragmatic common interest which compensates for the supposed selfishness at the level of the gene and to a certain extent also in the genetic competition between individuals. Emotions themselves thus form a central area where moral sentiments gain credible biological meaning and explain why, despite a twenty times higher level ovf violence in males than females, humans are nevertheless far less violent to one another on an individual footing then many animal societies.

It remains to be seen whether the formation of male coalitions in humans, which Ridley emphasizes in discussing apes and bottle-nose dolphins has more than balanced the female reproductive strategies in reproductive paradox.

Telling Hawks from Doves

For their size, vampire bats have very big brains. The reason is that the neocortex the clever bit at the front of the brain Is disproportionately big compared to the routine bits towards the rear. Vampire bats have by far the largest neocortexes of all bats. It is no acci 'dent that they have more complex social relationships than most bats, including, as we have seen, bonds of reciprocity between unrelated neighbours in a group. To play the reciprocity game, they need to recognize each other, remember who repaid a favour and who did not, and bear the debt or the grudge accordingly. 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.' Indeed, so tight is the correlation that you can use it to predict the natural group size of a species whose group size is unknown. Human beings, this logic suggests, live in societies 150 strong. Although many towns and cities are bigger than this, the number is in fact about right. It is roughly the number of people in a typical hunter-gatherer band, the number in a typical religious commune, the number in the average address book, the number in an army company, the maximum number employers prefer in an easily run factory. It is, in short, the number of people we each know well.' 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. In a society of individuals that you recognize and know well, you need never play the prisoner's dilemma blindly. You can pick and choose your partners. You can pick those you know have cooperated in the past, you can pick those whom others have told you can be trusted, and you can pick those who signal that they will cooperate. You can discriminate. Large, cosmopolitan cities are characterized by ruder people and more casual insult and violence than small towns or rural areas. Nobody would dream of driving in their home suburb or village as they do in Manhattan or central Paris shaking fists at other drivers, hooting the horn, generally making clear their impatience. It is also 'dely acknowledged why th's is the case. B'g cities are anonymous places. You can be as rude as you like to strangers in New York, Paris or London and run only a minuscule risk of meeting the same people again (especially if you are in a car). What restrains you in your home suburb or village is the acute awareness of reciprocity. If you are rude to somebody, there is a good chance they will be in a position to be rude to you in turn. If you are nice to people, there is a good chance your consideration will be returned. In the conditions in which human beings evolved, in small tribes where to meet a stranger must have been an extremely rare event, this sense of reciprocal obligation must have been palpable it still is among rural people of all kinds. Perhaps Tit-for-tat is at the root of the human social instinct; perhaps it explains why, of all mammals, the human being has come closest to matching the naked mole rat in its social instincts.

The hunting of the snark

After Robert Axelrod's tournaments, there was a minor backlash against Tit-for-tat in game theory. Economists and zoologists alike began to crowd in with awkward objections.

The main problem that zoologists have with Tit-for-tat is that there are so few good examples of it from nature. Apart from Wilkinson's vampire bats, Trivers's reef cleaning stations and a handful of examples from dolphins, monkeys and apes, Tit-for-tat just is not practised. These few examples are a meagre return on the effort that went into looking for Tit-for-tat in the ig8os. To some zoologists the conclusion is stark: animals ought to play Tit-for-tat, but they don't. A good example is lions. Lionesses live in tight-knit prides, each 'de defend'ng'ts territory against rival prides (male lions just attach themselves to prides for the sex, and do little of the work, either catching food or defending territory unless it be from other males). Lionesses advertise their territorial ownership by roaring, so it is quite easy to fool them into thinking they face a serious invasion by playing tape-recorded roars in their territories. This Robert Heinsohn and Craig Packer did to some Tanzanian lions and watched their reaction. The lionesses usually walk towards the sound to investigate, some rather enthusiastically, others a little reluctantly. This is fertile territory for Tit-for-tat. A brave lioness, who leads the approach to the intruder', should expect a reciprocal favour from a laggard, who hangs back: next time the laggard should lead, and risk danger. But Heinsohn and Packer found no such pattern. Leaders recognize laggards and keep looking back at them as if resentfully, but they usually lead the next time, too. Laggards are laggards.

We suggest that female lions may be classified according to four discrete strategies: 'unconditional cooperators' who always lead the response, 'unconditional laggards' who always lag behind, 'conditional cooperators' who lag least when they are most needed, and 'conditional laggards' who lag farthest when they are most needed.1

There is absolutely no sign of punishment for the laggards, or reciprocity. The leaders just have to accept that their courage goes unappreciated. The lionesses do not play Tit-for-tat. The fact that other animals do not often play Tit-for-tat does not prove that human beings do not build their societies upon reciprocity.

As we shall see in the next few chapters, the evidence that human society is riddled with reciprocal obligations is great and growing greater all the time. Like language and opposable thumbs, reciprocity might be one of those things that we have evolved for our own use, but that few other animals have found the use or the mental capacity for. Kropotkin may have been wrong, in other words, to expect mutual aid in insects just because it is present in people. None the less, the zoologists have a point. The simple idea of Tit-for-tat seems better suited to the simplified world of computer tournaments than the mess that is real life.

Tit-for-tat's Achilles' heel

Economists had a different problem with Tit-for-tat. Axeirod's discoveries, published in a series of papers and later in a book called The Evolution of Co-operation, caught the popular imagination and 'dely publ'c'zed in the press. This fact alone would have earned them contempt from envious game theorists, and sure enough the sniping soon began. Juan Carlos Martinez-Coll and jack Hirshlelfer put it bluntly: 'A rather astonishing claim has come to be widely accepted: to wit that the simple reciprocity behaviour known as Tit-for-tat is a best strategy not only in the particular environment modeled by Axelrod's simulations but quite generally.' They argued that one could just as 'ly design the conditions of a tournament in which Tit-for-tat easi I would not do well, and, more worryingly, it seemed to be impossible to simulate a world where both nasty and nice strategies cohabited yet that is the world we live in.4 Among the' harshest critics has been Ken Binmore. He argues that it is vital to notice that, even in Axelrod's simulations, Tit-for-tat never wins a single game against a 'nastier' strategy: therefore, it is singularly bad advice to play Tit-for-tat if you enter a single game, rather than a series of games. You're just a sucker if you do. Axelrod, remember, added the scores obtained in matches between many different strategies. Tit-for-tat won by accumulating many highscoring draws and losses, not by winning bouts. Binmore believes that the very fact that we find Tit-for-tat such a natural idea 'we all know deep down inside that it is reciprocity that keeps society going' makes us uncritically keen to accept a mathematical rationalization of the notion. He adds: 'One must be very cautious indeed before allowing oneself to be persuaded to accept general conclusions extrapolated from computer simulations." Much of this criticism misses the point. Axelrod should no more be criticized for failing to capture everything that happens in the world than Newton should be for failing to explain politics in terms of gravity. Everybody thought the prisoner's dilemma taught a bleak lesson, not only that it was rational to defect but also that it was stupid of people not to realize this. Yet Axelrod discovered that, in his words, 'the shadow of the future' alters this completely. A simple, nice strategy won his tournaments again and again. Even if his conditions later prove unrealistic, even if life is not precisely such a tournament, Axelrod's work has thoroughly demolished the working assumption of all those who had studied the subject before: that the only rational thing to do in a prisoner's dilemma is to be nasty. Nice guys can finish first. 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 highscoring 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. Some of the highland people in central New Guinea, who live in a network of dangerous, unstable, but reciprocal alliances and feuds between tribes, have recently taken up football but, finding it a little too much for the blood pressure to lose a game, they have adjusted the rules. The game simply continues until each side has scored a certain number of goals. A good time is had by all, but there is no loser and every goal scorer can count themselves a winner. It is not a zero-sum game. 'Don't you see?' remonstrated the referee, a newly arrived priest, after one such drawn game. 'The ob'ect of the game is to try to beat the other team. Someone has to win!' The captains of the rival teams replied, patiently, 'No, Father. That's not the way of things. Not here in Asmat. If someone wins then someone else has to lose and that would never do. 16 This is bizarre only because it is an idea we find so instinctively hard to grasp, at least in the context of games (I have my doubts about the joys of New Guinea football). Take the case of trade. It is axiomatic among economists that the gains from trade are mutual: if two countries increase their trade, both are better off. Yet this is not the way the man in the street, let alone his demagogue representative, sees it. To them, trade is a competitive matter: exports good, imports bad. Imagine a football tournament slightly different from the New Guinea case. In this competition the winner of the league is the team to score the most goals, not the one that wins most games. Now imagine that some teams decide to play normal football, letting in as few goals as possible and scoring as many as possible. Other teams try a different strategy. They let the other team score a goal, then try to score themselves. If allowed, they return the favour; and so on. You can quickly see which teams will do best: the ones that are playing Tit-for-tat. Football has thus been changed from a zero-sum game to a non-zero-sum game. 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. However, in one important respect, Binmore and the other critics were right. Axelrod had been too hasty in concluding that Tit-for-tat itself is 'evolutionarily stable' meaning that a population playing Tit-for-tat is immune to invasion by any other strategy. This conclusion was undermined by further computer-simulated tournaments, like Axelrod's third one, in which Rob Boyd and Jeffrey Lorberbaum showed that it was easy to design tournaments that Tit-for-tat does not win.

In these tournaments, to recapitulate, a random mix of strategies battle against each other for control of a finite space, by breeding at the rate defined by their points in the last game: 5, 3, i or o. In these conditions, nasty strategies, such as 'Always defect', do well at first, exploiting the naive cooperative strategies and crowding them out. But soon they get sluggish and feeble, because they only ever meet each other, and only ever get i point. Now is when Tit-fortat comes into its own. Playing against'Always defect', it soon defects to deprive the other of more than one 5-point temptation; but, playing against itself, it cooperates and reaps 3 points. Therefore, so long as one Tit-for-tat can find a few others and form even a small cooperative cluster, they can thrive and drive 'Always defect' extinct.7 But it is now that Tit-for-tat's weaknesses emerge. For example, Tit-for-tat is vulnerable to mistakes. Remember that it cooperates until it meets a defection, which it then punishes. When two Tit-fortat players meet they cooperate happily, but if one starts to defect, purely by random mistake, then the other retaliates and before long both are locked in a miserably unprofitable round of mutual defections. To take an all-too-real example, when an IRA gunman in Northern Ireland, aiming at a British soldier, kills an innocent Protestant bystander, the mistake can spark a revenge murder of a randomly selected Catholic by a loyalist gunman, which in turn is avenged, and so on ad infinitum. Such a series of deaths in Northern Ireland was known for many years as tit-for-tat killing. Because of such weaknesses, it was apparent that Tit-for-tat's success in the Axelrod tournaments was largely a function of their form. The tournaments 'ust happened not to show up these weaknesses. In a world where mistakes are made, Tit-for-tat is a secondrate strategy, and all sorts of other strategies prove better. The clear conclusions that Axelrod had drawn became clouded as ever more rococo elaborations of new strategies were invented.

Enter Pavlov

The scene now shifts to Vienna, where Karl Sigmund, an ingenious mathematician with a playful cast of mind, was giving a seminar on game theory to a group of students one day in the late ig8os. One of the students in the audience, Martin Nowak, decided there and then to abandon his own studies of chemistry and become a game theorist. Sigmund, impressed by Nowak's determination, set him the task of solving the thicket of complication that had entrapped the prisoner's dilemma in the wake of Tit-for-tat. Find me the perfect strategy in a realistic world, said Sigmund. Nowak designed a different kind of tournament, one in which nothing was certain, and everything was statistically driven. Strategies made random mistakes with certain probabilities, or switched between tactics in the same probability-driven manner. But the system could 'learn' or evolve by keeping improvements and dropping unsuccessful tactics. Even the probabilities with which they did things were open to gradual evolutionary change. This new realism proved remarkably helpful, stripping away all the rococo complications. Instead of several strategies equally capable of winning the game, one clearly came out on top. It was not Tit-for-tat but a very near relation called Generous-Tit-for-tat (which I will call Generous, for short). Generous occasionally forgives single mistakes. That is, about one-third of the time it magnanimously overlooks a single defection. To forgive all single defections a strategy known as Tit-for-two-tats is merely to invite exploitation. But to do so randomly with a probability of about a third is remarkably effective at breaking cycles of mutual recrimination while still remaining immune to exploitation by defectors. Generous will spread at the expense of Tit-for-tat in a computer population of pure Tit-for-tat players that are making occasional mistakes. So, ironically, Tit-for-tat merely paves the way for a nicer strategy than itself. It is John the Baptist, not the Messiah. But neither is Generous the Messiah. It is so generous that it allows even nicer, more nafve strategies to spread. For exai-nple, the simple strategy 'Always cooperate' can thrive among Generous players, though it does not actually defeat them; it can creep back from the dead. But 'Always cooperate' is a fatally generous strategy and is 'ly 'nvaded by 'Always defect', the nastiest strategy of all. Among easi I .Generous players, 'Always defect' gets nowhere; but when some start praying 'Always cooperate', it strikes. So, far from ending up with a happy world of reciprocity, Tit-for-tat ushers in Generous, which can usher in 'Always cooperate', which can unleash perpetual defection, which is back where we started from. One of Axelrod's conclusions was wrong: there is no stable conclusion to the game. As the summer of -iggz began, Sigmund and Nowak were depressed by their conclusion that there is no stable solution to the prisoner's dilemma game. It is the sort of untidy decision game theorists dislike. But, as luck would have it, Sigmund's wife, a historian, was due to spend the summer in Schloss Rosenburg, a fairytale castle in the Waldviertel of lower Austria, as the guest of a Graf whose ancestry she was studying. Sigmund asked Nowak along and they brought a pair of laptop computers to play prisoner's dilemma .tournaments. The castle is used as a falconry school and, by day, the two mathematicians found themselves distracted every two hours by the thousand-foot dives of imperial eagles practising their technique over the castle courtyard. It was a suitably medieval setting for the 'ousting matches they organized inside their computers. They went back to the beginning and entered into the lists of their tournaments all sorts of strategies that had been rejected before, trying to find one that not only won, but could remain stable after winning the tournament. They tried giving their playing automata a slightly better memory. Instead of just reacting to the partner's last play, as Tit-for-tat does, the new strategies remembered their own last play as well and acted accordingly. One day, quite suddenly, as the eagles dived past the window, inspiration struck. An old strategy first tried by who else? Anatol Rapoport, suddenly kept coming out on top. Rapoport had dismissed the strategy as hopeless, calling it Simpleton. But that was because he had pitted it against 'Always defect', against which it was indeed naive. Nowak and Sigmund entered it into a world dominated by Tit-for-tat and it not only defeated the old pro, but proved invincible thereafter. So, although Simpleton cannot beat 'Always defect', it can steal the show once Tit-for-tat has extinguished 'Always defect'. Once again, Tit-for-tat plays John the Baptist. Simpleton's other name is Pavlov, though some say this is even more misleading it is the opposite of reflexive. Nowak admits that he should call it by the cumbersome but accurate name of Win-stay/ Lose-shift, but he cannot bring himself to do so, so Pavlov it remains. Pavlov is like a rather simplistic roulette gambler. If he wins on red, he sticks to red next time; if he loses, he tries black next time. For win, read 3 or 5 (reward and temptation); for lose, read i or o (punishment and sucker's pay-off). This principle that you don't mend your behaviour unless it is broken underlies a lot of everyday activities, including dog training and child-rearing. We bring up our children on the assumption that they will continue doing things that are rewarded and stop doing things that are punished. Pavlov is nice, like Tit-for-tat, in that it establishes cooperation, reciprocating in that it tends to repay its partners in kind, and forgiving, like Generous, in that it punishes mistakes but then returns to cooperating. Yet it has a vindictive streak that enables it to exploit 'fve cooperators I'ke 'Always cooperate'. If it comes up against a sucker, it keeps on defecting. Thus it creates a cooperative world, but does not allow that world to decay into a too-trusting Utopia where free-riders can flourish. Yet Pavlov's weakness was well known. As Rapoport had discovered, it is usually helpless in the face of 'Always defect', the nasty strategy. It keeps shifting to cooperation and getting the sucker's pay-off hence its original name of Simpleton. So Pavlov cannot spread until Tit-for-tat has done its job and cleared out the bad guys. Nowak and Sigmund, however, discovered that Pavlov only shows this flaw in a deterministic game one in which all the strategies are defined in advance. In their more realistic world of probability and learning, where each strategy rolled a die to decide what to do next, something very different happened. Pavlov quickly adjusted its probabilities to the point where its supremacy could not be challenged by 'Always defect'. It was truly evolutionarily stable.'

The fish that play chicken Do animals or people use Pavlov? Until Nowak and Sigmund published their idea, one of the neatest examples of Tit-for-tat from animals was an experiment by Manfred Milinski using fish called sticklebacks. Sticklebacks and minnows are eaten by pike, and they react to the presence of a pike by leaving the school in a small scouting party and approaching it cautiously to assess the danger it poses. This apparently foolish courage must have some reward; naturalists think it gives the prey some valuable information. If, for example, they conclude that the pike is not hungry or has just fed, they can return to feeding themselves. When two sticklebacks inspect a predator together, they move forward in a series of short spurts, one fish taking the initiative and risk each time. If the pike moves, both dash back again. Milinski argued that this was a series of small prisoner's dilemmas, each fish having to offer the 'cooperative' gesture of the next move forward, or take the 'defector's' option of letting the other fish go ahead alone. By an ingenious use of mirrors, Milinski presented each fish with an apparent companion (in fact its own reflection) that either kept up with it or lagged further and further behind as it got nearer the pike. Milinski at first interpreted his results in terms of Tit-for-tat: the trial fish was bolder with a cooperator than a defector. But, on hearing about Pavlov, he recalled that his fish would seem to switch back and forth between cooperation and defection when presented with a consistently defecting companion that had previously once cooperated like Pavlov but unlike Tit-for-tat. It may seem absurd to look at fish, expect'tng to find sophisticated game theorists, but there is, in fact, no requirement in the theory that the fish understand what it is doing. Reciprocity can evolve in an entirely unconscious automaton, provided it interacts repeatedly with other automata in a situation that resembles a prisoner's dilemma as the computer simulations prove. Working out the strategy is the job not of the fish itself, but of evolution, which can then program it into the fish.

Pavlov is not the end of the story. Since Nowak has moved to Oxford it became inevitable that somebody at Cambridge had to take up the challenge of surpassing Pavlov. That somebody was Marcus Frean, who tried a new trick of playing the game in a more realistic fashion, in which the two players do not have to move simultaneously. Vampire bats do not do each other favours at the same moment. They take turns there would be no point in simply swapping food for fun. Frean ran a tournament of this 'alternating prisoner's dilemma' inside his computer and, sure enough, there evolved a strategy that defeated Pavlov. Frean calls it Firm-but-fair. Like Pavlov it cooperates with cooperators, returns to cooperating after a mutual defection and punishes a sucker by further defection. But unlike Pavlov it continues to cooperate after being the sucker in the previous round. It is, therefore, slightly nicer. The significance of this is not to raise Firm-but-fair into a new god, but to notice that making the game asynchronous makes guarded generosity even more rewarding. This accords with common sense. If you have to act before your partner and vice versa, it pays to try to elicit cooperation by being nice. You do not, in other words, greet strangers with a scowl lest they form a bad opinion of you; you greet them with a smile.

The first moralizers

Yet a more formidable problem looms. The prisoner's dilemma is a two-person game. Cooperation can, it seems, evolve spontaneously if a pair of individuals plays the game together indefinitely. Or, to put it more accurately, in a world where you only ever meet your immediate neighbour, it pays to be nice to him. But the world is not like that. Reciprocity has a hard enough time producing cooperation even within a pair: the pair must be able to police their contract by being sure of encountering and recognizing each other again. How much harder is it among three individuals or more? The larger the group, the more inaccessible are the benefits of cooperation and the greater the obstacles that stand in the way. Indeed, Rob Boyd, a theorist, has argued that not only Tit-for-tat but any reciprocal strategy is simply inadequate to the task of explaining cooperation in large groups. The reason is that a successful strategy in a large group must be highly intolerant of even rare defection, or else free-riders individuals who defect and do not reciprocate will rapidly spread at the expense of better citizens. But the very features that make a strategy intolerant of rare defection are those that make it hard for reciprocators to get together when rare in the first place.9 Boyd himself provides one answer. Reciprocal cooperation might evolve, he suggests, if there is a mechanism to punish not ' just defectors, but also those who fall to punish defectors. Boyd calls this a 'moralistic' strategy, and it can cause anv individually costly behaviour, not just cooperation, to spread, whether it causes group benefit or not. This is actually a rather spooky and authoritarian message. Whereas Tit-for-tat suggested the spread of nice behaviour among selfish egoists without any authority to tell them to be nice, in Boyd's moralism we glimpse the power that a fascist or a cult leader can wield. There is another and potentially more powerful answer to the problem of free-riders in large groups: the power of social ostracism. If people can recognize defectors, they can simply refuse to play games with them. That effectively deprives the defectors of Temptation (5), Reward (3) and even Punishment (i). They do not get a chance to accumulate any points at all. Philip Kitcher, a philosopher, designed an 'optional prisoner's dilemma' game to explore the power of ostracism. He populated a computer with four kinds of strategist: discriminating altruists, who play only with those who have never defected on them before; willing defectors, who always try defecting; solitaires, who always opt out of any encounter; and selective defectors who are prepared to play with those who have never defected before but then, treacherously, defect on them. Discriminating altruists (DAs) invading a population of solitaires soon prevail, because they find each other and reap the Reward. But surprisingly, selective defectors cannot then invade a population of DAs, whereas DAs can invade one of selective defectors. In other words, discriminating altruism, which is just as 'nice' as Tit-for-tat, can reinvade anti-social populations. It is no more stable than Tit-fortat, because of a similar vulnerability to a gradual take-over by undiscriminating cooperators. But its success hints at the power of ostracism to help in solving prisoners' dilemmas." Kitcher's programs relied entirely on the past behaviour of partners to judge whether they could be trusted. But discriminating between potential altruists need not be so retrospective. It might be possible to recognize and avoid potential defectors in advance. Robert Frank, an economist, set up an experiment to find out. He put a group of strangers in a room together for just half an hour, and asked them each to predict privately which of their fellow subjects would cooperate and which would defect in a single prisoner's dilemma game. They proved substantially better than chance at doing so. They could tell, even after 'ust thirty minutes' acquaintance, enough about somebody to predict his cooperativeness. Frank does not claim that this is too surprising. We spend a good deal of our lives assessing the trustworthiness of others, and we make instant 'udgements with some confidence. He poses a thought experiment for those unconvinced. 'Among those you know (but have never observed with respect to pesticide disposal), can you think of anyone who would drive, say, forty-five minutes to dispose of a highly toxic pesticide properly? If yes, then you accept the premise that people can predict cooperative predispositions."'

Can fish be trusted?

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. Cooperators can seek out cooperators. Of course, for such a system to work, individuals must learn to recognize each other, which is not an easy feat. I have no idea whether a herring in a shoal of 10,000 fish or an ant in a colony of 10,000 insects, ever says to itself: 'There's old Fred again.' But I feel quite safe in assuming that it does not. On the other hand I feel equally secure in asserting that a vervet monkey probably knows by sound and sight every other member of its troop, because the primatologists Dorothy Cheney and Robert Seyfarth have proved as much. Therefore, a monkey has the necessary attributes for reciprocating cooperation, but a herring does not. However, I may be maligning fish. Manfred Milinksi and Lee Alan Dugatkin have discovered a remarkably clear pattern of ostracism in stickleback fish when they risk their lives to inspect predators. A fish will tolerate more defection on the part of another fish that has continuously cooperated in the past than one that has not cooperated. And sticklebacks tend to pick the same partners to accompany them on predator-inspection visits each time choosing partners who are consistently good cooperators. In other words, not only are the sticklebacks quite capable of recognizing individuals, but they seem capable of keeping individual scores remembering which fish can be 'trusted'. This is a puzzling discovery, in the light of how rare reciprocal cooperation is in the animal kingdom. Compared to nepotism, which accounts for the cooperation of ants and every creature that cares for its young, reciprocity has proved to be scarce. This, presumably, is due to the fact that recriprocity requires not only repetitive interactions, but also the ability to recognize other individuals and keep score. Only the higher mammals apes, dolphins, elephants and a few others are thought to possess sufficient brain power to be so discriminating for more than a handful of individuals. Now we know that sticklebacks can also keep score, at least for one or two 'friends', this assumption may have to be relaxed. 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. Think about it: reciprocity hangs, like a sword of Damocles, over every human head. He's only asking me to his party so I'll give his book a good review. They've been to dinner twice and never asked us back once. After all I did for him, how could he do that to me? If you do this for me, I promise I'll make it up later. What did I do to deserve that? You owe it to me. Obligation; debt; favour; bargain; contract; exchange; deal ... Our language and our lives are permeated with ideas of reciprocity. In no sphere is this more true than in our attitude to food.

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. When I first grasped it, I slept badly for many nights, trying to find some alternative that did not so roughly challenge my sense of good and evil. Understanding this discovery can undermine commitment to morality it seems silly to restrain oneself if moral behavior is just another strategy for advancing the interests of one's genes. Some students, I am embarrassed to say, have left my courses with a na'fve notion of the selfish-gene theory that seemed to them to justify selfish behavior, despite my best efforts to explain the naturalistic fallacy." Randolph Nesse, 1994

The isolated island of Maku in the central Pacific is inhabited by a fierce, tribal Polynesian people called the Kaluame. They hold a unique place in the history of science because of two studies that took place simultaneously of the same local chieftain, an ample man known as Big Kiku. The first study was done by an economist interested in reciprocal exchange; the second by an anthropologist out to document the innate selflessness of human beings. Both experts had noticed a peculiarity of Big Kiku, that he demanded that his followers have their faces tattooed to show their loyalty. One night, just as it grew dark, four frightened and hungry men stumbled into the camp where the two intellectuals were eating their dinner in competitive silence. They asked Big Kiku to be fed with some cassava. He told them: 'If you get a tattoo on your face, then you will be fed a cassava root in the morning.' The two intellectuals looked up, interested. How, wondered the economist, do the four men know that Big Kiku will keep his word? He might tattoo them and then still not feed them. I simply do not believe that Big Kiku is serious, replied the anthropologist. I think he is merely bluffing. You and I know what a charming fellow he is, and he surely would not refuse food to a man just because he did not get a tattoo! They argued late into the night over a bottle of whisky, and the sun was already high into the sky when they rose the next morning. Recalling the four hungry refugees, they asked Big Kiku what had happened.

This was his reply: 'All four left at sun-up. But since you are so clever, I will set you a test, and if you get it wrong, I will tattoo your faces myself. The first man got a tattoo, the second had nothing to eat, the third did not get a tattoo and to the fourth I gave a large cassava root. Now, you tell me whi ch of the four you need to know more about to answer your curiosity about my behaviour: the first, the second, the third or the fourth. If you ask about one that is irrelevant to your inquiry, or fail to ask about one that is relevant, you lose, and I get to tattoo your face.' He laughed loud and long. As you have probably realized by now, there is no such place as Maku, no such people as the Kaluame and no such philosopher king as Big Kiku. But put yourself in the position of each of the two intellectuals in turn and answer the question. It is a well-known psychological puzzle called the Wason test, usually played with four cards, and you are required to turn over the minimum number of cards to test a certain if-then rule. People are surprisingly bad at the Wason test in some circumstances for instance, if presented with it as an abstract piece of logic but surprisingly good at it in others. In general, the more the puzzle is presented as a social contract to be policed, the easier people find it, even if the contract is deeply foreign and the social context unfamiliar. I have slightly embroidered a version of the Wason test told by Leda Cosmides and John Tooby, a husband and wife team of psychologist and anthropologist; they invented Big Kiku and his culture in order to present people with a wholly strange world in which they could not bring their own cultural biases to bear. The economist's puzzle is comparatively easy. About threequarters of seventy-five students at Stanford University got it right when asked. Remember he is interested in knowing if Big Kiku kept his word. To avoid having his face tattooed, the economist must ask Big Kiku whether he gave food to the first man (who got the tattoo) and whether the second (who went away hungry) got the tattoo. The other two are irrelevant, because Big Kiku had not broken his word if he refused food to a man who did not get a tattoo, or indeed if he fed a man who did not; he simply said if the man got a tattoo then he would be fed.

The anthropologist's problem is logically similar, but it proves to be much harder. When it is posed to Stanford students, the majority of them gets it wrong, however carefully it is worded., The anthropologist is looking for evidence that Big Kiku is unconditionally generous: he sometimes lets people eat when they have not got the tattoos; he does not care about those who got the tattoo. So he is only interested in the third and fourth men: he who got no tattoo (and might have been fed anyway), and he who was fed (and might not have got a tattoo). The first two are irrelevant because Big Kiku was not generous to either. Why is the second problem so much harder? The answer goes straight to the heart of the question posed in Chapter Six: whether humans have an instinct to reciprocate, and to see that others reciprocate. The economist is looking for cheats, who do not keep their word, a familiar and easy idea that comes naturally to all of us; the anthropologist is looking for altruists, who offer a bargain and then give away their side of it anyway. Not only is that an unusua thing to find going on, it is also something that poses no threat to your own self-interest if somebody else does it. If somebody offers to buy you lunch, you do not worry about his generosity, but his normal lack of it; you worry about whether he might intend to ask a favour of you in return.' The Big Kiku case was not an isolated experiment; it was part of a long series of experiments in which psychologists gradually narrowed down the question of what makes a Wason test hard and what makes one easy, itself part of the discovery that the laws of thought and the laws of logic are very different things. Familiarity with the context and the storv makes no difference, they found. Logical simplicity matters very little: some complicated Wason tests are easy to solve. The fact that the puzzle is presented as a social contract per se does not matter, either. What matters is whether the person being tested is asked to identify cheats in social contracts people who take the benefits without paying the cost. People are bad at looking for altruism; better at looking for cheating. People are bad at judging tests where it is hard to guess the cost and the benefit of the various actions. They are bad at looking for rewards and losses when these are not 1 illicit in some sense. Even when the Wason test was adapted by one student for the Achuar people of Ecuador, who are almost completely isolated from contact with the Western world, there was strong evi 'dence that they too were far better at detecting cheats of social contracts than at other forms of reasoning.4 In short, the Wason test seems to tap straight into a part of the human brain that is a ruthless and devastatingly focused calculating machine. It treats every problem as a social contract arrived at between two people and looks for ways to check those who might cheat the contract. It is the exchange organ. This seems ridiculous; how can a part of the brain instinctively 'know' social contract theory? Has Rousseau somehow infiltrated the genes? It is no more absurd than arguing that the brainn knows calculus because a sportsman can catch a ball by extrapolating its trajectory, or grammar because you know how to make a past tense from a previously unknown verb, or that the eye is capable of higher physics and mathematics because it slightly adjusts the colour of an object according to the general colour of the whole scene, thus correcting for the redness of the evening light. All the exchange organ does is robotically employ specialized inference engines designed by natural selection to find violations of exchange contracts agreed between two parties. As a species, wherever we live and in whatever culture, we seem to be uniquely aware of cost-benefit analysis of exchanges. We simply do not have organs that are designed to spot other, logically comparable but socially different events, such as when people have made mistakes or broken prescriptive rules that are not social contracts. Nor are we good at spotting irrational situations that defy descriptive rules of no social significance. There are people with certain kinds of brain damage who prove to have lost almost nothing except the ability to reason about social exchange; there are, conversely, people especially most schizophrenics who fall most tests of intelligence except those that concern reasoning about social exchange. Imprecise as the concept seems, the human animal does appear to have an exchange organ in its brain. We shall see later that neurology already supports such an outlandish idea.'

We invent social exchange in even the most inappropriate situations. It dominates our relationship with the supernatural, for example. We frequently and universally anthropomorphize the natural world as a system of social exchanges. 'The gods are angry because of what we have done' we say to justify a setback in the Tro'an war, a plague of locusts in ancient Egypt, a drought in the Namib desert or a piece of bad luck in modern suburbia. I frequently kick or glower at recalcitrant tools or machines, cursing the vindictiveness of inanimate ob'ects, blatant in my anthropomorphism. If we please the gods with sacrifices, food offerings, or prayer we expect to be rewarded with military victory, good harvests or a ticket to heaven. Our steadfast refusal to believe in good or bad luck, but 'bute it to some punishment for a broken promise or reward for a good deed, whether we are religious or not, is idiosyncratic to say the least.' We do not know for sure where the social-exchange organ is, or how it works, but we can tell it is there as surely as we can tell anything else about our brains. 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.7

Revenge is irrational

Biologists discovered nepotism and reciprocity in the 196os because they caught the self-interest virus. They suddenly started asking, about everything that had evolved, 'But what's in it for the indi'dual?' Not the species, or the group the 'nd'v'dual. Such a question led them to a fascination with animal cooperation and hence to the central importance of the gene. Behaviour that is not in the interest of the individual might be in the interest of its genes. Material self-interest for genes became the watchword of biology. But a curious thing has happened in recent years. Economists, who founded their whole discipline on the question 'What's in it for the individual?', have begun to back away. Much of the innovation in economics of recent years has been based on the alarming discovery by economists that people are motivated by something other than material self-interest. In other words, just as biology shook off its woolly collectivism and donned the hair shirt of individualism, economics has begun to go the other way: to try to explain why people do things that are against their selfish interests. The most successful of those attempts is that by Robert Frank, an economist. His is a theory of why we have emotions, founded in a combination of the new cynical biology and the less pecuniary economics. It may seem odd that a man who has written a textbook on microeconomics should steal in where psychologists have floundered, and explain the function of emotion. But that is exactly the point he makes. Human motives are the stuff of economics, whether they are rational and material or not. Robert Trivers, who brought gene-centred cynicism to much of biology, once wrote: 'Models that attempt to explain altruistic behavior in terms of natural selection are models designed to take the altruism out of altruism." This is an old idea for social sciences, as familiar to the Glasgow philosophers of the eighteenth century as to modern economists such as Amartya Sen: if you are nice to people because it makes you feel better, then your compassion is selfish, not selfless. Likewise, in the world of biology, an ant slaves away celibate on behalf of its sisters not out of the goodness of its little heart (an organ it does not possess in a form that we would recognize), but out of the selfishness of its genes. A vampire bat feeds its neighbour for sound, ultimately selfish reasons. Even baboons that repay social favours are being prudent rather than kind. What passes for virtue, said Michael Ghiselin, is a form of expediency. (Christians should pause before they feel superior: they teach that you should practise virtue to get to heaven a pretty big bribe to appeal to their selfishness.)9

The key to understanding Robert Frank's theory of the emotions is to keep in mind this distinction between superficial irrationality and ultimate good sense. Frank began his seminal book, Passions within Reason, with a description of a bloody massacre by some Hatfields of some McCoys. The murderers were being irrational and self-defeat'tng in their act of quite unnecessary revenge, which in turn led to revenge on them. Any rational person would not pursue a feud, any more than he would let guilt or shame prevent him from stealing a friend's wallet. 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. In the same way, ants that rear their sisters rather than their daughters seem superficially irrational, or for that matter mice that rear daughters rather than looking after themselves are apparently ignoring material self-interest. Yet probe beneath the surface of the individual to its genes and all becomes clear. The ants and the mice are selflessly serving the material interests of selfish genes. In the same way, Frank argues that human beings who let emotion rather than rationality govern their lives may be making immediate sacrifices, but in the long term are making choices that benefit their well-being. Noticeth-atl-amnot usingthe word emotion here to mean 'affect': hysterical or paranoid people may seem highly irrational, but they are in the grip of an affect, rather than a specific emotion. 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."

Commit yourself

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? The economist Thomas Schelling has dramatized the commitment problem in a story known as the kidnapper's dilemma. Suppose a kidnapper gets cold feet and wishes he had not taken his victim. He proposes to release her but only if she agrees not to give evidence against him. Yet he knows if he lets her go, she will be grateful, but she will have no reason by then not to break her promise and go straight to the police. She will be out of his power. So she assures him that she will do no such thing, but her assurances carry no conviction to the kidnapper, because he knows they are not worth the air they are spoken in; to go back on them will cost her nothing. The dilemma is really hers, not his. How can she commit herself to her side of the bargain? How can she make it costly for herself to break the deal? She cannot. Schelling suggested that she should in some way compromise herself, by revealing a terrible crime she has committed in the past so that the kidnapper could be witness against her, and mutual deterrence would ensure that the deal sticks. But how many kidnappers' victims have something as awful as kidnapping to confess to? It is not a realistic solution to the dilemma, which remains insoluble for lack of enforceable commitment. In real life, commitment problems are, however, more soluble, for an intriguing reason. We use our emotions to make credible commitments for us. Consider two of the examples Frank gives of such problems. First, two friends consider starting a restaurant, one cooking the food, the other keeping the books; each could easily cheat the other. The cook could exaggerate the cost of food; the accountant could cook the books. Second, a farmer must deter his neighbour from letting cattle stray into his wheat; yet the threat of a lawsuit is not credible because the costs would outweigh the value of the damage done. These are not esoteric or trivial problems; they are the kind of thing that faces all of us repeatedly throughout life. Yet in each case, a rational person would come out badly. The rational entrepreneur would not start the restaurant for fear of being cheated or would herself cheat for fear that her equally rational partner was cheating, and would thereby ruin the business. The rational farmer would not be able to deter his rational neighbour from letting cattle into his wheat, because he would not waste money going to court. To bring reason to such problems, and to assume that others would, is to lose the opportunities they represent. Rational people would be unable to convince each other of their commitment and would never close the deals. But we don't bring reason to such problems; we bring irrational commitment driven by our emotions. The entrepreneur does not cheat for fear of shame or guilt, and she trusts her partner, knowing her to be a woman who does not like to face shame or guilt herself a person of honour. The farmer fences in his cattle knowing that his neighbours rage and obstinacy will cause him to sue even if it means ruining himself in the process.

In this way 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. A few years ago, Dutch researchers discovered that if the male of a pair of small birds called blue tits is wounded by a sparrowhawk during egg laying, its mate will promptly seek another male to mate with. This is rational; the wounded male may die or pine away, and the female would be better off with another male. In order to interest another male in rearing her brood, she should give him a share of their paternity. But to human ears, the female's behaviour is almost unbelievably callous and heartless, however sensible it is. Likewise, I noticed when studying animals how lacking they usually are in a sense of grudge. They do not nurture thoughts of revenge on those that have harmed them; they simply get on with life. This is sensible, but it does mean that an animal can harm another without considering the consequences. 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."

Fairness matters

In his original paper on reciprocal altruism, Robert Trivers came up with much the same idea: emotions mediate between our inner calculator and our outer behaviour. 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. Likewise, the emotions of gratitude and sympathy are surprisingly calculating. Psychological experiments reveal as experience confirms that people are much more grateful for acts of kindness that cost the donor some large effort or inconvenience than for easy acts, even if the benefit received is the sanie. We all know the feeling of resentment at an unsolicited act of generosity whose intent is not to do a kindness but to make us feel the need to do a kindness in return. The emotion of guilt, Trivers argued, is used to repair relationships once the guilty person's cheating has been exposed. People are more likely to make altruistic reparative gestures out of guilt when their cheating has become known to others. All in all, the human emotions looked to Trivers like the highly polished toolkit of a reciprocating social creature." But whereas Trivers couched his version of the theory in terms of immediate reward through reciprocity, Frank reckons the commitment model rescues the altruism question from the clutches of such cynics. It does not try to take the altruism out of altruism. 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. Therefore, far from being truly altruistic, the cooperative person is merely looking to his long-term self-interest, rather than the short term. Far from dethroning the rational man beloved of classical economists, Frank is merely redefining him in a more realistic way. Amartya Sen has called the caricature of the short-sighted selfinterested person a 'rational fool'. If the rational fool turns out to be taking short-sighted decisions then he is not being rational, just short-sighted. He is indeed a fool who fails to consider the effect of his actions on others. 14 However, such quibbling aside, Frank's insight is still remarkable. At its core lies the idea that acts of genuine goodness are the price we pay for having moral sentiments those sentiments being valuable because of the opportunities they open in other circumstances. So when somebody votes (an irrational thing to do, given the chances of affecting the outcome), tips a waiter in a restaurant she will never revisit, gives an anonymous donation to charity or flies to Rwanda to bathe sick orphans in a refugee camp, she is not, even in the long run, being selfish or rational. She is simply prey to sentiments that are designed for another purpose: to elicit trust by demonstrating a capacity for altruism. This is not really an alternative interpretation from that proposed in the last chapter that people do good deeds in order to win prestige that, through indirect reciprocity, they can later cash as a more practical good. Richard Alexander takes the philosopher Peter Singer to task for arguing that the existence of national blood banks that rely on generosity proves people are not motivated by reciprocity. It is true that people give blood in Britain in no expectation that they will be paid or will get preferential treatment If they need blood themselves. You get a cup of weak tea and a polite thank-you. But, says Alexander, 'Who among us is not a little humble in the presence of someone who has casually noted that he just came back from "giving blood"?" People are not generally very secretive about blood donation. Giving blood and working in Rwanda both enhance your reputation for virtue and therefore make people more likely to trust you in prisoner's dilemmas. They scream out 'I am an altruist; trust me.' 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. Imagine, says Frank, that you have left Li,ooo in an envelope with your name and address on it in a crowded theatre. Of all those people whom you know, are there some who you think would be more likely to return the envelope if they found it? Of course there are. So you distinguish among your acquaintances according to how much you can trust them to cooperate with you even in a situation in which they could get away undetected with not cooperating. Indeed, as Frank has shown in his own experiments, if people are asked to play the prisoner's dilemma with each of a group of strangers in turn, but given just thirty minutes to meet the partners first, they prove remarkably good at predicting which of the strangers will defect and which will cooperate 'n the game (see Chapter Five).

Consider, for example, how important a smile is from somebody you are meeting for the first time. It is a hint that this person desires to trust and be trusted; it could be a lie, of course, though plenty of people would bet that they could distinguish a fake smile from a real' one. Still harder is it to laugh convincingly if you are not amused, and in many people a blush is wholly involuntary. So our faces and our actions seem to advertise with disarming frankness just what is going on in our heads, which seems thoroughly disloyal of them. Dishonesty is so physiological it can be detected by a machine: a lie detector. Anger, fear, guilt, surprise, disgust, contempt, sadness, grief, happiness all are universally recognizable, not just in one culture, but across the globe. Such easily detected emotions plainly benefit the species in that they allow trust to go to work in society, but what possible use are they to the individual? Go back to the prisoner's dilemma tournaments of Chapter Three and recall how, in the world of defectors, a Tit-for-tat stratagem cannot take hold unless it finds other cooperators. Likewise, says Frank, in a world of people who find it easy to deceive themselves and their facial muscles who are good at lying a poor self-deceiver would suffer. But once he could find another poor self-deceiver, the two would hit it off. They would be able to trust each other and avoid playing the game with anybody else. To identify people who are not opportunists is an advantage; to be identified as a non-opportunist is equally an advantage for it attracts others of the same stamp. Honesty really is the best policy for the emotions. One of Frank's strongest examples is the issue of fairness. Consider the game known as the 'ultimatum bargaining game'. Adam is given $1oo in cash and told to share it with Bob. Adam must say how much he intends to give to Bob and, if Bob refuses the offer, neither wi 'll get anything at all. If Bob accepts, then he gets what Adam has offered. The logical thing for Adam to do, assuming he thinks Bob is also a rational fellow, is to offer Bob a derisory sum, say $1, and keep the remaining $99. Bob should rationally accept this, because then he is ii better off. If he refuses, he will get nothing. But not only do very few people offer such a small sum when asked to act Adam's part, even fewer accept such exiguous offers when playing Bob's part. By far the commonest offer made by real Adams is $50. Like so many games in psychology, the purpose of the ultimatum bargaining game is to reveal how irrational we are and wonder at the fact. But Frank's theory has little difficulty explaining this 'Irrationality', even finding it to be sensible. People care about fairness as well as self-interest. They do not expect to be offered such a derisory sum by someone in Adam's position and they refuse it because irrational obstinacy is a good way of telling people so. Likewise, when playing Adam, they make a 'fair' offer of 50:50 to show how fair and trustworthy they are should future opportunities arise that depend on trust. Would you risk your good reputation with your friends for a lousy $50? But this is the reasoning of reciprocity, not fairness. The economist Vernon Smith has subtly varied the ultimatum bargaining game to reveal that it does not say much about an innate sense of fairness, but instead supports the argument that reciprocity motivates people. If, among a group of students, the right to play Adam is 'earned' by scoring in the top half of the class on a general knowledge test, then Adams tend to be less generous. If the rules are changed so that Bob must accept the offer which Smith calls the 'dictator game' then once more the offers are less generous. If the experiment is presented not as an ultimatum given by Adam, but as a transaction between a buyer and a seller in which Bob must quote a price, then again Adams are less generous. And if the experiment is conducted in such a way as to protect the anonymity of Adam, then again Adams are less generous. Now, with their identity protected from the experimenter, seventy per cent of Adams offer nothing in the dictator game. It is as if the subjects think the experimenter will not ask them back (the experimental sessions are profitable) unless they display pro-social behaviour. In all these new circumstances, people should be just as generous if it is an innate sense of fairness that motivates them. Yet they are not. They reveal a strict sense of opportunism instead. So why are they generous in the original game? Because, argues Smith, they are obsessed with reciprocity. Even when the game is only played once, they are concerned to protect their personal reputation for being somebody who can be trusted not to be too nakedly opportunistic at others' expense." Smith uses a game called the 'centipede game' to ram home the message. In this game Adam and Bob have the chance to pass or take the money on each turn. The longer they pass, the more money there is, but eventually the game hits the end and Adam gets the money. So Bob should reason with himself that he should not pass on his last go; then Adam should reason that Bob will do this so he should not pass on his penultimate go; and so on until each is led to the conclusion that he should stop the game at the first chance. Yet people do not. They routinely allow others to win lots of money by passing. The reason, clearly, is that they are trading rewarding the other person for not being selfish, hoping for reciprocal generosity when their turn comes. Yet there is no systematic switching of roles. Robert Frank's commitment model is in some ways a rather oldfashioned idea. What he is saying is that morality and other emotional habits pay. The more you behave in selfless and generous ways the more you can reap the benefits of cooperative endeavour from society. You get more from life if you irrationally forgo opportunism. The subtle message of both neoclassical economics and neoDarwinian natural selection that rational self-interest rules the world and explains people's behaviour is inadequate and normatively dangerous. Says Frank:

[Adam] Smith's carrot and Darwin's stick have by now rendered character development an all but completely forgotten theme in many industrialized countries. 17

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

The moral sense

Robert Frank is an economist, but his ideas echo and are echoed by the writings of two psychologists. Jerome Kagan is a child psychologist whose studies of the inheritance, development and causes of personality lead him inexorably to emphasize emotion rather than reason as the wellspring of human motivation. The desire to escape or avoid guilt, says Kagan, is a human universal, common to all people in all cultures. The kinds of events that cause guilt may vary from culture to culture being unpunctual, for instance, is a very Western thing to feel guilty for but the reaction to guilt is the same the world over. Morality requires an innate capacity for guilt and empathy, something children of two years old clearly lack. Like most innate capacities (language, say, or good humour), though, the moral one can be nurtured or suppressed by different kinds of upbringing; so to say that the emotions that fuel morality are innate is not to say they are immutable. Kagan's theory of childhood morality is therefore like Frank's commitment model in its emphasis on irrational emotions.

Construction of a persuasive basis for behaving morally has been the problem on which most moral philosophers have stubbed their toes. I believe they will continue to do so until they recognize what Chinese philosophers have known for a long time: namely, that feeling, not logic, sustains the superego."

Incidentally, it seems as if vervet monkeys, like two-year-olds, completely lack the capacity for empathy. If one vervet monkey makes an alarm call, it does not cease merely because another is already calling so must already be aware of the danger. Vervet monkeys never correct their babies' mistakes in making alarm calls. And vervets do not make alarm calls when a baboon approaches. Baboons eat baby vervets but not adults. Thus the monkey's alarm is sublimely self-centred. As Dorothy Cheney put it after studying both vervets and baboons, 'Signalers do not recognize the mental state of listeners, so they cannot communicate with the intent of appeasing those who are anxious or informing those who are ignorant.' They cannot empathize. This is such an obvious difference between human beings and other animals that it is hard to step back and see it for the idiosyncrasy that it is. We do not cut into queues, because we care what other people even strangers think of us. Other animals do not. A decade after Kagan's book was published and six years after Frank's, James Q. Wilson published The Moral Sense, which makes many of the same arguments from a criminologist's perspective. 'What most needed explanation, it seemed to me, was not why some people are criminals but why most people are not.' Wilson chides philosophers for not taking seriously the notion that morality resides in the senses as a purposive set of instincts. They mostly view morality as merely a set of utilitarian or arbitrary preferences and conventions laid upon people by society. Wilson argues that morality is no more a convention than other sentiments such as lust or greed. When a person is disgusted by injustice or cruelty he is drawing upon an instinct, not rationally considering the utility of the sentiment, let alone simply regurgitating a fashionable convention. For example, even if you dismiss charitable giving as ultimately selfish saying that people only give to charity in order to enhance their reputations you still do not solve the problem because you then have to explain why it does enhance their reputations. Why do other people applaud charitable activity? We are immersed so deeply in a sea of moral assumptions that it takes an effort to imagine a world without them. A world without obligations to reciprocate, deal fairly, and trust other people would be simply inconceivable." Psychologists, therefore, are converging with Robert Frank's economic argument that emotions are mental devices for guaranteeing commitment.

But perhaps the most remarkable convergence comes from the study of broken brains. There is a small part of the prefrontal lobe of the human brain, which, when damaged, turns you into a rational fool. People who have lost that part of their brain are superficially normal. They suffer no paralysis, no speech defect, no loss in their senses, no diminution in their memory or general intelligence. They do just as well in psychological tests as they did before their accidents. Yet their lives fall apart for reasons that seem more psychiatric than neurological (oh false dichotomy!). They fall to hold down jobs, lose their inhibitions, and become paralytically indecisive. But this is not all that happens to them. They also literally lose their emotions. They greet misfortune, joyful news and infuriating checks with equanimity and reason. They are simply flat, emotionally.

Antonio Damasio, who described these symptoms from twelve patients in his book Descartes's Error, thinks it is no accident that decision making and emotion go together. His patients become so cold-blooded about rationally weighting all the facts before them that they cannot make up their minds. 'Reduction in emotion may constitute an equally important source of irrational behavior,' he speculates." In short, if you lack all emotions, you are a rational fool. Damasio makes this case without apparently knowing that economists like Robert Frank, biologists like Robert Trivers and psychologists like Jerome Kagan have come to similar conclusions from different evidence. It is a remarkable coincidence. Patience is a virtue, a virtue is a grace, and Grace is a little girl who wouldn't wash her face. This meaningless little ditty now seems to contain a gem of an insight that summarizes the commitment model's main discovery. Virtue is indeed a grace or an instinct as we might put it in these less Augustinian days. It is something to be taken for granted, drawn on and cherished. It is not something we must struggle to create against the grain of human nature as it would be if we were pigeons, say, or rats with no social machine to oil. It is the instinctive and useful lubricant that is part of our natures.

So instead of trying to arrange human institutions in such a way as to reduce human selfishness, perhaps we should be arranging them in such a way as to bring out human virtue.

Let others be altruists

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. indeed, what would you say to somebody close to you who was being truly selfless a child, say, or a close friend, who was continually turning the other cheek, doing little tasks at work that others should have done, working for no reward in a hospital emergency room, or giving his weekly pay to charity? If he did it occasionally, you would praise him. But if he did it every week, year after year, you would start to question it. In the nicest way you might hint that he should look out for himself a little more, be just a touch more selfish. 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. Also, the more we posture in favour of altruism, the better for us. I believe this explains the general mistrust in which both economics and selfish-gene biology is held. Both disciplines claim repeatedly and with little effect that they are being misunderstood; they are not recommending selfishness, they are recognizing it. It is only realistic, economists say, to expect human beings to react to incentives with a view of their self-interest not just or good, but realistic. 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'. If the commitment model is right, though, the critics of selfish schools have a point, for everything becomes normative. If people are not rational maximizers of self-interest, then to teach them that such behaviour would be logical is to corrupt them. Indeed, this is just what Robert Frank and many others have found: those students who have been taught the nostrums of neoclassical economics are much more likely to defect in prisoner's dilemma games than, for instance, astronomy students. The virtues of tolerance, compassion and justice are not policies towards which we strive, knowing the difficulties upon the way, but commitments we make and expect others to make gods we pursue. Those who raise difficulties, such as economists saying that selfinterest is our principal motivation, are to be distrusted for their motives in not worshipping the gods of virtue. That they do so suggests that they may not themselves be believers. They show, as it were, an unhealthy interest in the subject of self-interest.

Theories of moral sentiments

Frank's 'theory of moral sentiments' fleshes out Adam Smith's, first advanced in his book of that name published in 1759. It also begins to build a bridge between Smith's apparently irrational assumption that people are driven by moral sentiments and his devotion to rational self-interest as the wellspring of a successful economy: a bridge between his first and second books. In his first book Adam Smith argued that if individuals had sufficient common interest in the good of their group, they would combine to suppress the activities of members acting contrary to the group's welfare. Bystanders would interfere to punish anti-social actions. But in his second book, Smith seemed to undermine this argument by suggesting that societies are not public goods carefully protected by individuals but are the almost inevitable side-effect of individuals striving in their own, individual interests.

The Germans, who, it seems, in their methodical manner commonly read both Theory of Moral Sentiments and the Wealtb of Nations, have coined a pretty term, Das Adam Smith Problem, to denote the failure to understand either which results from the attempt to use the one in the interpretation of the other."

Frank's theory of moral sentiments resolves this paradox and builds another, more modern bridge between reciprocity and groupishness. By emphasizing that the challenge in the prisoner's dilemma game is to attract the right partner, he shows how reciprocators precipitate out of society, leaving the selfish rationalists to their fate. The virtuous are virtuous for no other reason than that it enables them to Join forces with others who are virtuous, to mutual benefit. 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.

The Source of War (an extract)

As for religion itself, the universalism of the modern Christian message has tended to obscure an obvious fact about religious teaching that it has almost always emphasized the difference between the in-group and the out-group: us versus them; Israelite and Philistine; Jew and Gentile; saved and damned; believer and heathen; Arian and Athanasian; Catholic and Orthodox; Protestant and Catholic; Hindu and Muslim; Sunni and Shia. Religion teaches its adherents that they are a chosen race and their nearest rivals are benighted fools or even subhumans. There is nothing especially surprising in this, given the origins of most religions as beleaguered cults in tribally divided, violent societies. Edward Gibbon noticed that a vital part of Roman military success was religion: 'The attachment of the Roman troops to their standards was inspired by the united influences of religion and of honour. The golden eagle, which glittered in the front of the legion, was the object of their fondest devotion; nor was it esteemed less impious than it was ignominious, to abandon that sacred ensign in the hour of danger."9 John Hartung, an anthropologist who pursues his training as a historian in his spare time, has taken the much loved Judaeo Christian phrase 'Love thy neighbour as thyself' and subjected it to searching scrutiny. It was devised, according to the biblical account in the Torah (Old Testament), at a time when the Israelites were in the desert, rent by dissension in the ranks and devastated by internecine violence. Three thousand people had died in a recent episode. Moses, anxious to maintain amity within the tribe, came up with the pithy aphorism about loving neighbours, but the context of his remark is clear. It refers directly to 'the children of thy people'. It does not profess general benevolence. 'A parochial perspective characterizes most religions,' says Hartung, 'because most religions were developed by groups whose survival depended upon competition with other groups. Such religions, and the ' in-group morality they foster, tend to outlive the competition that spawned them.' Hartung does not stop there.

The ten commandments, he reveals apply to Israelites but not heathen people, as reaffirmed throughout the Talmud, by later scholars such as Maimonides and repeatedly by the kings and prophets of the Torah. Modern translations, by footnotes and Judicious editing or mistranslation, usually blur this point. But genocide was as central a part of God's instructions as morality. When Joshua killed twelve thousand heathen in a day and gave thanks to the Lord afterwards by carving the ten commandments in stone, including the phrase 'Thou shalt not kill', he was not being hypocritical. Like all good group-selectionists, the Jewish God was as severe towards the out-group as he was moral to the in-group.

This is not to pick on the Jews. No less an authority than Margaret Mead asserted that the injunction against murdering human beings is universally interpreted to define human beings as members of one's own tribe. Members of other tribes are subhuman. As Richard Alexander has put it, 'the rules of morality and law alike seem not to be designed explicitly to allow people to live in harmony within societies but to enable societies to be sufficiently united to deter their enemies. "' 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. St Paul, living in exile among the Gentiles, started the idea of converting rather than exterminating the heathen. But the practice, rather than the preaching, of Christianity has been less inclusive. The Crusades, the Inquisitions, the Thirty Years War and the sectarian strife that still afflicts communities like Northern Ireland and Bosnia, testify to a continuing tendency for Christians to love only those neighbours who share their beliefs Christianity has not notably diminished ethnic and national conflict; if anything it seems to have inflamed it.

A million people cannot be wrong, or can they?

In parallel with the evolutionary discovery of conformism, psychol- ogists and economists have discovered it, too. In the 1950s, an American psychologist named Solomon Asch did a series of experiments that tested people's tendency to be intimidated into conforming. The subject entered a room where there were nine chairs in a semi-circle, and was seated next from the end. Eight other people arrived one by one and occupied the other chairs. Unknown to the subject, they were all stooges - accomplices of the experimenter. Asch then showed the group two cards in turn. On the first was a single line; on the second there were three lines of different length. Each person was then asked which of the three lines was the same length as the line they had first seen. This was not a difficult test; the answer was obvious, because the lines were two inches different in length. But the subject's turn to answer came eighth, after seven others had already given their opinion. And to the subject's astonishment the seven others not only chose a different line, but all agreed on which line. The evidence of his senses conflicted with the shared opinions of seven other people. Which to trust? On twelve out of eighteen occasions the subject chose to follow the crowd and name the wrong line. Asked afterwards if they had been influenced by others' answers, most subjects said no! They not only conformed, they genuinely changed their bellefs.

Trust (an excerpt)

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. Human beings have social instincts. They come into the world equipped with predispositions to learn how to cooperate, to discriminate the trustworthy from the treacherous, to commit themselves to be trustworthy, to earn good reputations, to exchange goods and information, and to divide tabour. In this we are on our own. No other species has been so far down this evolutionary path before us, for no species has built a truly integrated society except among the inbred relatives of a large family such as an ant colony. We owe our success as a species to our social instincts; they have enabled us to reap undreamt benefits from the division of tabour for our masters the genes. They are responsible for the rapid expansion of our brains in the past two million years and thence for our inventiveness. Our societies and our minds evolved together, each reinforcing trends in the other. Far from being a universal feature of animal life, as Kropotkin believed, this instinctive cooperativeness is the very hallmark of humanity and what sets us apart from other animals. The evolutionary perspective is a long one. This book has in passing tried to nail some myths about when we adopted our cultured habits. I have argued that there was morality before the Church; trade before the state; exchange before money; social contracts before Hobbes; welfare before the rights of man; culture before Babylon; society before Greece; self-interest before Adam Smith; and greed before capitalism. These things have been expressions of human nature since deep in the hunter-gatherer Pleistocene. Some of them have roots in the missing links with other primates. Only our supreme self-importance has obscured this so far. But self-congratulation is premature. We have as many darker as lighter instincts. The tendency of human societies to fragment into competing groups has left us with minds all too ready to adopt prejudices and pursue genocidal feuds. Also, though we may have within our heads the capacity to form a functioning society, we patently fail to use it properly. Our societies are torn by war, violence, theft, dissension and inequality. We struggle to understand why, variously apportioning blame to nature, nurture, government, greed or gods. The dawning self-awareness that this book has chronicled ought indeed must have some practical use. Knowing how evolution arrived at the human capacity for social trust, we can surely find out how to cure its lack. Which human institutions generate trust and which ones dissipate it? Trust is as vital a form of social capital as money is a form of actual capital. Some economists have long recognized this. 'Virtually every commercial transaction has within itself an element of trust,' says the economist Kenneth Arrow. Lord Vinson, a successful British entrepreneur, cites as one of his ten commandments for success in business: 'Trust everyone unless you have a reason not to.' Trusr, like money, can be lent ('I trust you because I trust the person who told me he trusts you'), and can be risked, hoarded or squandered. It pays dividends in the currency of more trust. Trust and distrust feed upon each other. As Robert Putnam has argued, soccer clubs and merchant guilds have long reinforced trust in the successful north of Italy and fallen apart because of lack of trust in the more backward and hierarchical south. That is why two such similar peoples as the north Italians and the south Italians, equipped with much the same mixtures of genes, have diverged so radically simply because of a historical accident: the south had strong monarchies and godfathers; the north, strong merchant communities.' Indeed, larger parallels spring to mind. Putnam argues that the North Americans developed a successful civic-minded society because they inherited a horizontally bonded version from the particular Britons who founded their cities, while the South Americans, stuck with the nepotism, authoritarianism and clientelism of medieval Spain, fell behind. You can take this too far. Francis Fukuyama argues unconvincingly that there is a broad difference between successful economies such as America and japan and unsuccessful ones such as France and China because of the latter's addiction to hierarchical power structures. None the less, Putnam is indisputably on to something. Social contracts between equals, generalized reciprocity between individuals and between groups these are at the heart of the most vital of all human achievements: the creation of society.'

The war of all against all

Much of this book has been a modern rediscovery with added genetics and mathematics of an age-old philosophical debate, a debate known by the name 'the perfectibility of man'. In various guises and at various times philosophers have argued that man is basically nice if he is not corrupted, or basically nasty if he is not tamed. Most famously, the debate pits Thomas Hobbes, on the side of nastiness, against jean-Jacques Rousseau on the side of niceness. Hobbes, though, was not the first to argue that man is a beast whose savage nature must be tamed by social contracts. Machiavelli said much the same two centuries before ('It must needs be taken for granted that all men are wicked,' he wrote). The Christian doctrine of original sin, refined by St Augustine, expressed a similar point: goodness comes as a gi 'ft from God. The Sophist philosophers of ancient Greece thought people inherently hedonistic and selfish. But it was Hobbes who made the argument political.4 Hobbes's intention, writing Leviathan in the i650s in the wake of a century of religious and political civil war in Europe, was to argue that strong sovereign authority was required to prevent a state of perpetual fratricidal struggle. This was an unfashionable notion, for most seventeenth-century philosophers hewed to the ideal of a bucolic state of nature, typified in the supposedly peaceful and plentiful lives of American Indians, to justify their own search for a perfectly ordered society. Hobbes turned this on its head, arguing that the state of nature was one of war, not peace.5 Thomas Hobbes was Charles Darwin's direct intellectual ancestor. Hobbes (i65i) begat David Hume (1739), who begat Adam Smith (I776), who begat Thomas Robert Malthus (I798), who begat Charles Darwin (i859). It was after reading Malthus that Darwin shifted from thinking about competition between groups to thinking about competition between individuals, a shift Smith had achieved in the century before.' The Hobbesian diagnosis though not the prescription still lies at the heart of both economics and modern evolutionary biology (Smith begat Friedman; Darwin begat Dawkins). At the root of both disciplines lies the notion that, if the balance of nature was not designed from above but emerged from below, then there is no reason to think it will prove to be a harmonious whole. John Maynard Keynes would later describe The Origin of Species as 'simply Ricardian economics couched in scientific language', and Stephen jay Gould has said that natural selection 4was essentially Adam Smith's economics read into nature'. Karl Marx made much the same point: 'It is remarkable,' he wrote to Friedrich Engels in June i86z, 'how Darwin recognises among beasts and plants his own English society with its division of labour, competition, opening up of new markets, "Inventions," and the Malthusian struggle for existence. It is Hobbes' bellum omnium contra omnes.17 Darwin's disciple, Thomas Henry Huxley, chose exactly the same quotation from Hobbes to illustrate his argument that life is a pitiless struggle. For primitive man, he said, 'life was a continual free fight, and beyond the limited and temporary relations of the family, the Hobbesian war of each against all was the normal state of existence. The human species, like others, plashed and floundered amid the general stream of evolution, keeping its head above the water as it best might, and thinking neither of whence nor whither.' It was this essay that provoked Kropotkin to write Mutual Aid. The argument between Huxley and Kropotkin had a personal edge. Huxley was a self-made man; Kropotkin an aristocratic revolutionary. Huxley was a meritocratic success with little time for dreamy outcast princes born in privilege; their falls from grace proved, to Huxley, their unfitness as surely as Huxley's own rise proved his fitness. 'It is open to us to try our fortune; and if we avoid impending fate, there will be a certain ground for believing that we are the right people to escape. Securus judicat orbis." It was a short step from Huxley's meritocracy to the cruelty of eugenics. Evolution worked by sorting the strong from the weak, and it could be given a helping hand. Predestined not by their god but by their genes, the Edwardians came enthusiastically to the logical conclusion and began to sort the wheat from the chaff. Their successors in America and Germany committed the naturalistic fallacy, and sterilized and murdered millions of people in the belief they were thus improving the species or race. Although this project reached obscene depths under Hitler, it was widely supported, especially in the United States, by those on the left of the political spectrum, too. Indeed, Hitler was merely carrying out a genocidal policy against inferior', incurable or reactionary tribes that Karl Marx and Friedrich Engels had advocated in 1849 and that Lenin had begun to practise as early as 1918. It is even possible that Hitler got his eugenics not from Darwin or Spencer but from Marx, whom he read carefully when in Munich in 19I3 and echoed closely on the topic. Many socialists were enthusiastic about eugenics, notably H. G. Wells who said, about 'black, and brown, and dirty-white, and yellow people who do not come into the new needs of efficiency' that they 'will have to go'.9 The Hobbesian search for a perfect society ended, therefore, in the gas chambers of Auschwitz, expressing not the human instinct for cooperation but the human instinct for genocidal tribalism, the Faustian bargain that comes, as we have seen, with groupishness."

The noble savage

Hobbesian views prevailed in the century between 1845 and 1945. In the century before and the half century after, kinder and more Utopian views of human nature dominated political philosophy. ...

... Indeed, given their immunity from criticism, Communist officials have consistently proved more corruptible and more nepotistic than democratic ones. Universal benevolence evaporates on the stove of human nature.'9 As Herbert Simon has put it, 'In our century we have watched two great nations, the People's Republic of China and the Soviet Union, strive to create a "new man," only to end up by acknowledging that the "old man" perhaps we should say the "old person" self-interested and concerned with his or her economic welfare, or the welfare of the family, clan, ethnic group, or province, was still alive and well."o Fortunately, there proved to be, in Lionel Trilling's words, 'a resi 'due of human quality beyond cultural control.' Otherwise, Russians would now be irredeemably corrupted people, which they plainly are not. Karl Marx designed a social system that would only have worked if we were angels; it failed because we were beasts. Human nature had not been changed at all. 'I would rather hope [that man has some innate nature] than be stuck with a human tabula rasa on which any tyrants or do-gooders can write their (always benign) messages at will. And I think man has such a nature, that it is intensely social, and that it gives the lie to all sanctimonious manipulators from Mill through Stalin,' said Robin Fox.1'

Conclusion (from Trust: Who stole the Community?)

Materially, everybody in the city is better off than a century ago, but that is the result of new technology, not government. Socially, the deterioration is marked. Hobbes lives, and I blame too much government, not too little. If we are to recover social harmony and virtue, if we are to build back into society the virtues that made it work for us, it is vital that we reduce the power and scope of the state. That does not mean a vicious war of all against all. It means devolution: devolution of power over people's lives to parishes, computer networks, clubs, teams, self-help groups, small businesses everything small and local. It means a massive disassembling of the public bureaucracy. Let national and international governments wither into their minimal function of national defence and redistribution of wealth (directly without an intervening and greedy bureaucracy). Let Kropotkin's vision of a world of free individuals return. Let everybody rise and fall by their reputation. I am not so nayve as to think this can happen overnight, or that some form of government is not necessary. But I do question the necessity of a government that dictates the minutest details of life and squats like a giant flea upon the back of the nation. For St Augustine the source of social order lay in the teachings of Christ. For Hobbes it lay in the sovereign. For Rousseau it lay in solitude. For Lenin it lay in the party. They were all wrong. The roots of social order are in our heads, where we possess the instinctive capacities for creating not a perfectly harmonious and virtuous society, but a better one than we have at present. We must build our institutions in such a way that they draw out those instincts. Pre-eminently this means the encouragement of exchange between equals. just as trade between countries is the best recipe for friendship between them, so exchange between enfranchised and empowered individuals is the best recipe for cooperation. We must encourage social and material exchange between equals for that is the raw material of trust, and trust is the foundation of virtue.