Conditional or tit-for-tat altruism cannot evolve in just any species. It requires members to recognize each other and have long memories, so as to be able to keep tally. A species that provides a shining example of reciprocal altruism is none other than the vampire bat. The bats, found in South America, hang out in colonies of a dozen or so adult females with their children. They feed by biting a small incision in the skin of sleeping animals, nowadays mostly cattle or horses, and injecting a special anticoagulant named, naturally enough, draculin. But their blood collection drives are not always successful. On any given night a third of the young bats and 7% of the adults are unsuccessful, according to a study by Gerald W. Wilkinson of the University of Maryland.
This could pose a serious problem because vampire bats must feed every three days, or they die. The colony’s solution, Wilkinson found, is that successful bats regurgitate blood to those who went hungry. Bats are particularly likely to donate blood to their friends, with whom they have grooming relationships, to those in dire need, and to those from whom they received help recently.192 The vampires’ reciprocal altruism must be particularly effective since the bats, despite the risk of death after three bloodless nights, can live for 15 years.
If social altruism has evolved among vampire bats, there is no reason why it could not also emerge among primates. And indeed it can be seen at work in the coalitionary politics of male chimpanzees, where the alpha male depends on allies to preserve his dominance of the male hierarchy. The biologist Robert L. Trivers, who first showed how reciprocal altruism could be favored by natural selection, suggested that in people a wide range of sophisticated behaviors grew up around it, including cheating (failure to return an altruistic favor to the giver), indignation at cheating, and methods to detect cheating.193
Many common emotions can be understood as being built around the expectation of reciprocity and the negative reaction when it is made to fail. If we like a person, we are willing to exchange favors with them. We are angry at those who fail to return favors. We seek punishment for those who take advantage of us. We feel guilty if we fail to return a favor, and shame if publicly exposed. If we believe someone is genuinely sorry about a failure to reciprocate, we trust them. But if we detect they are simulating contrition, we mistrust them.194
The instinct for reciprocity, and the cheater-detection apparatus that accompanies it, seem to be the basis for a fundamental human practice, that of trade with neighboring groups. Long distance trade is one of the characteristic behaviors of the human societies that emerged in the Upper Paleolithic age starting some 50,000 years ago. Tribal societies developed trading systems of considerable sophistication. The Yit Yoront, a foraging society of northern Australia, lived until recently in the Stone Age. One of their most necessary possessions, used in everything from hunting to wood-gathering, were hafted stone axes. But they lived on an alluvial coast and the nearest stone quarry was four hundred miles away. How did they acquire their polished stone axes? They made a product much in demand with their neighbors to the south, spears tipped with the barbs of stingrays. The spears were traded inland, through a long line of trading partners, being exchanged at each stage for a varying number of stone axes. The spear/axe exchange rate was sufficient at each trading post to push stone axes northward and pull barb-tipped spears southward.195
Trade is a foundation of economic activity because it gives the parties to a transaction a strong incentive to specialize in making the items that the other finds valuable. But trade depends on trust, on the decision to treat a total stranger as if he were a member of the family. Humans are the only species to have developed such a degree of social trust that they are willing to let vital tasks be performed by individuals who are not part of the family. This set of behaviors, built around reciprocity, fair exchange and the detection of cheaters, has provided the foundation for the most sophisticated urban civilizations, including those of the present day.
Reciprocity, and an ability to calculate the costs and benefits of cooperation, underpin our social life, writes the economist Paul Seabright, “making it reasonable for us to treat strangers as though they were honorary relatives or friends.” It is remarkable that this behavior evolved at a time when primitive warfare was at its most intense and people had every reason to regard strangers with deep suspicion. Strangers can still be dangerous, yet in the right circumstances we habitually trust them. “The knowledge that most people can be trusted much of the time to play their part in the complex web of social cooperation has had dramatic effects on the psychology of our everyday life,” Seabright says, making it possible “to step nonchalantly out of the front door of a suburban house and disappear into a city of ten million strangers.”196 Without this innate willingness to trust strangers, human societies would still consist of family units a few score strong, and cities and great economies would have had no foundation for existence.
How might this greater level of trust have arisen? Two hormones, known as oxytocin and vasopressin, are emerging as central players in modulating certain social behaviors in the mammalian brain. The hormones are generated in the pituitary gland at the base of the brain and have effects both on the body and in the brain. Oxytocin induces both labor in childbirth and the production of milk. Its effects on the mind, at least in experimental animals, have the general property of promoting affiliative or trusting behavior, lowering the natural resistance that animals have to the close proximity of others.
So what does oxytocin do in people? Researchers at the University of Zurich have found that it substantially increases the level of trust. Oxytocin, they say, “specifically affects an individual’s willingness to accept social risks arising through interpersonal interactions.” The findings emerged from giving subjects a sniff of oxytocin before playing a game that tested trusting behavior. 197
If the biological basis of trusting behavior is mediated in this manner, the degree of trust could easily be ratcheted up or down in the course of human evolution by genetic changes that either increased individuals’ natural production of the hormone or enhanced the brain’s response to it. Thus hunter-gatherers might have a genetically lower response to oxytocin while city-dwellers would have evolved a greater sensitivity. Whatever the exact mechanism, it is easy to see how greater levels of trust might have evolved at various stages in human evolution, given that there is a biological basis for the behavior.
Trust is an essential part of the social glue that binds people together in cooperative associations. But it increases the vulnerability to which all social groups are exposed, that of being taken advantage of by freeloaders. Freeloaders seize the benefits of social living without contributing to the costs. They are immensely threatening to a social group because they diminish the benefits of sociality for others and, if their behavior goes unpunished, they may bring about the society’s dissolution.
Human societies long ago devised an antidote to the freeloader problem. This freeloader defense system, a major organizing principle of every society, has assumed so many other duties that its original role has been lost sight of. It is religion.
The Evolution of Religion
The essence of religion is communal: religious rituals are performed by assemblies of people. The word itself, probably derived from the Latin religare, meaning to bind, speaks to its role in social cohesion. Religious ceremonies involve emotive communal actions, such as singing or dancing, and this commonality of physical action reinforces the participants’ commitment to the shared religious views.
The propensity for religious belief may be innate since it is found in societies around the world. Innate behaviors are shaped by natural selection because they confer some advantage in the struggle for survival. But if religion is innate, what could that advantage have been?
No one can describe with certainty the specific needs of hunter-gatherer societies that religion evolved to satisfy. But a strong possibility is that religion coevolved with language, because language can be used to deceive, and rel
igion is a safeguard against deception. Religion began as a mechanism for a community to exclude those who could not be trusted. Later, it grew into a means of encouraging communal action, a necessary role in hunter-gatherer societies that have no chiefs or central authority. It was then co-opted by the rulers of settled societies as a way of solidifying their authority and justifying their privileged position. Modern states now accomplish by other means many of the early roles performed by religion, which is why religion has become of less relevance in some societies. But because the propensity for religious belief is still wired into the human mind, religion continues to be a potent force in societies that still struggle for cohesion.
A distinctive feature of religion is that it appeals to something deeper than reason: religious truths are accepted not as mere statements of fact but as sacred truths, something that it would be morally wrong to doubt. This emotive quality suggests that religion has deep roots in human nature, and that just as people are born with a propensity to learn the language they hear spoken around them, so too they may be primed to embrace their community’s religious beliefs.
Can the origin of religion be dated? A surprising answer is yes, if the following argument is accepted. Like most behaviors that are found in societies throughout the world, religion must have been present in the ancestral human population before the dispersal from Africa 50,000 years ago. Although religious rituals usually involve dance and music, they are also very verbal, since the sacred truths have to be stated. If so, religion, at least in its modern form, cannot pre-date the emergence of language. It has been argued earlier that language attained its modern state shortly before the exodus from Africa. If religion had to await the evolution of modern, articulate language, then it too would have emerged shortly before 50,000 years ago.
If both religion and language evolved at the same time, it is reasonable to assume that each emerged in interaction with the other. It is easy enough to see why religion needed language, as a vehicle for the sharing of religious ideas. But why should language have needed religion?
The answer may have to do with the instinct for reciprocal altruism that is a principal cohesive force in human society, and specifically with its principal vulnerability, the freeloaders who may take advantage of the system without returning favors to others. Unless freeloaders can be curbed, a society may disintegrate, since membership loses its advantages. With the advent of language, freeloaders gained a great weapon, the power to deceive. Religion could have evolved as a means of defense against freeloading. Those who committed themselves in public ritual to the sacred truth were armed against the lie by knowing that they could trust one another.
The anthropologist Roy Rappaport argued that sanctified statements were early societies’ antidote to the misuse of the newly emerged powers of language. “This implies that the idea of the sacred is as old as language,” he wrote, “and that the evolution of language and of the idea of the sacred were closely related, if not bound together in a single mutual causal process.” The emergence of the sacred, he suggested, “possibly helped to maintain the general features of some previously existing social organization in the face of new threats posed by an ever-increasing capacity for lying.”198
For early societies making the first use of language, there had to be some context in which statements were reliably and indubitably true. That context, in Rappaport’s view, was sanctity. This feature has been retained to a considerable degree in modern religions, which are centered around sacred truths, such as “The Lord Our God the Lord is One,” or “There is no god but God.” These sacred truths are unverifiable, and unfalsifiable, but the faithful nevertheless accept them to be unquestionable. In doing so, like assemblies of the faithful since the dawn of language, they bind themselves together for protection or common action against the unbelievers and their lies.
From his study of the Maring, primitive agriculturalists of the New Guinea central highlands, Rappaport also recognized that ritual was an essential source of authority in an egalitarian society without headmen or ruling elites. It was by their attendance at ritual dances that the Maring would commit themselves to fight as their host’s allies in the next war cycle. “It is plausible to argue that religious ritual played an important role in social and ecological regulation during a time in human history when the arbitrariness of social conventions was increasing but it was not yet possible for authorities, if they existed at all, to enforce compliance,” he wrote.
Rappaport’s ideas about the role of religion in early societies have been buttressed by a remarkable series of excavations in the Oaxaca valley of Mexico. The archaeologists Joyce Marcus and Kent V. Flannery traced the development of religion over a 7,000-year period as the people of the valley went through four stages of social development, from hunters and gatherers, to a settled egalitarian society, to a society ruled by an elite, and finally to an archaic state known as the Zapotec state. As the Oaxacan people’s society evolved, so too did their form of religion.199
At the hunting and gathering stage, Joyce and Flannery found signs of a plain dance floor, its sides marked by stones. The dance floor, assuming it was used like those of modern hunter-gatherers, would have been the site of ritual dancing on ad hoc occasions when many different groups came together for initiations and courtship.
By 1500 BC the Oaxacans had developed strains of maize that allowed them to settle down and practice agriculture (the reverse of the sequence in the Near East, where settlement long preceded agriculture). At first their society was egalitarian, as it had been in their hunter-gatherer days, but their rituals became more formal. Marcus and Flannery have excavated four men’s houses, all oriented in the same direction, which may have been determined by the sun’s path at spring equinox. The orientation suggests that religious ceremonies were now held at fixed times, determined by astronomical events. The men’s houses, to judge by practice in contemporary societies, may have been open only to men who had passed acceptability tests and been initiated into secret rituals.
By 1150 BC the third stage of society had began to emerge, with an elite who lived in large houses, wore jade-studded clothes and deformed their skulls in childhood as a sign of nobility. The men’s houses were replaced with temples, also oriented in the same direction. Religious practice had become more elaborate, the archaeologists found, with ritual bloodletting, a symbolic self-sacrifice, and the cooking and eating of sacrificial victims.
The fourth stage of society, the Zapotec state, which was founded in 500 BC, was accompanied by a more complex form of religion. The temples now had rooms for a special caste of religious officers, the priests.
The advent of the priests marked the culmination of a steady trend in the evolution of Oaxacan ritual, its growing exclusivity. At the hunter-gatherer stage, the ritual dances were open to everyone. By the time of the men’s houses, only initiated members of the public could participate in rituals, and by the stage of the Zapotec state, religion had come under the control of a special priestly caste.
What underlay this coevolution of religion with social structure? It seems that the important coordinating role of ritual in hunter-gatherer societies did not end when leaders and elites emerged in settled societies. Instead, the elites coopted the ritual practices as another mechanism of social control and as a means of justifying their privileged position. Making the religion more exclusionary gave the elites greater power to control the believers. To justify the ruler’s position, new truths, also unverifiable and unfalsifiable, were added as subtexts to the religion’s sacred postulates, such as “The chief has great mana,” “Pharaoh is the living Horus,” or “Henry is by the Grace of God King.”
Rappaport believed that the conditions that enabled authorities to exercise civil power emerged only recently, and that for much of human existence rulers invoked sanctity as a principal source of their authority. Even archaic states were theocratic, at least to begin with. Modern states too, despite the ample civil power at their disposal, have not
entirely dispensed with appeals to religious cohesion and authority. Even in a society like that of the United States, political allegiance is sealed with the declaration of “One nation under God.”
Religion’s other ancient role, that of protecting the community from freeloaders, can also been seen still at work in contemporary societies. Among ultra-Orthodox Jews in New York’s diamond district, the level of trust is so high that multi-million-dollar deals can be sealed by a handshake. Islam is said to have spread through Africa as a facilitator of trade and trust.200
Trust and cohesiveness are nowhere more important than in wartime. Contemporary religions preach the virtues of peace in peacetime but in war the bishops are expected to bless the cannon, and official churches almost always support national military goals. “Religion is superbly serviceable to the purposes of warfare and economic exploitation,” writes the biologist Edward O. Wilson, noting that it is “above all the process by which individuals are persuaded to subordinate their immediate self-interest to the interests of the group.”201
Why does religion persist when its primary role, that of providing social cohesion, is now supplied by many other cultural and political institutions? While religion may no longer be socially necessary, it nevertheless fills a strong need for many people, and this may reflect the presence of genetic predisposition. Wilson, for one, believes that religion has a genetic basis, that its sources “are in fact hereditary, urged into birth through biases in mental development encoded in the genes.”
Religion, language and reciprocity are three comparatively recent elements of the glue that holds human societies together. All seem to have emerged some 50,000 years ago. But a far more ancient adaptation for social cohesiveness, one that set human societies on a decisively different path from those of apes, was the formation of the pair bond. Much of human nature consists of the behaviors necessary to support the male-female bond and a man’s willingness to protect his family in return for a woman’s willingness to bear only his children.
Before the Dawn: Recovering the Lost History of Our Ancestors Page 20