A second powerful influence favoring group selection, besides conformity within groups, is warfare between them, especially wars as frequent as those in pre-state societies. The more cohesive or altruistic group is likely to win, diminishing or eliminating its opponent. The importance of warfare as an evolutionary force has been demonstrated in mathematical models of the group selection process constructed by Samuel Bowles, an economist interested in evolution. Using an equation developed by George Price for tracking genetic variation within and between groups, Bowles has devised a model that shows how intimately altruism and warfare are related, a theme discussed earlier in relation to morality.
Altruism and war coevolved, Bowles concludes. “The group-oriented behaviors that make cooperation for mutual benefit possible among humans also make large-scale lethal warfare possible,” he writes. “And frequent warfare ... may have been an essential contributor to the evolution of precisely the altruistic traits that facilitate war making.”71
The insight explains why human nature is so contradictory, capable both of the most sickening cruelty and of the most self-denying care for others: the roots of altruism and of aggression are inextricably intertwined in evolutionary history.
Bowles has recently tried to make his model more realistic by feeding into it data from hunter gatherer groups relating to group size, the genetic variation between groups, and the frequency of conflict. He finds that death due to warfare makes up a sizeable fraction of all deaths among foragers—13 percent according to archaeological data, 15 percent according to ethnographic reports. To understand just how heavy a toll this is, consider the percentage of deaths due to warfare in the United States and Europe during the twentieth century, the epoch of two world wars: less than 1 percent of male deaths.72
Bowles argues that periods of intense conflict are likely to have ensued toward the end of the Pleistocene ice age when world climate fluctuated violently. The encroaching glaciers that rolled down over Europe and East Asia during the Last Glacial Maximum, which lasted from 20,000 to 15,000 years ago, would have diminished livable areas and pitted groups against one another in a conflict for survival.
A high mortality in conflict would explain a paradox that has long puzzled demographers. Hunter gatherer groups can increase by more than 2 percent a year, yet global human population grew at less than 0.1 percent until the advent of agriculture 10,000 years ago. Heavy attrition through warfare and climatic change would have driven group selection to significant levels. “Genetic differences between early human groups are likely to have been great enough so that lethal intergroup competition could account for the evolution of altruism,” Bowles concludes.
One expression of altruism is in religious behavior. By devoting time and resources to religious activities, rather than looking after his own family, an individual contributes to behavior that benefits the group. The evolutionary shaping of religious behavior has been explored by David Sloan Wilson. After reading a passage by a seventeenth-century Hutterite author comparing the community of the faithful to a beehive, he was struck by the possibility that group selection, in which he had long been interested as a matter of evolutionary theory, might explain the emergence of religion. In his book Darwin’s Cathedral he argues, with the help of several case studies, that group selection can indeed explain many features of religion.
His thesis is that human groups function as units subject to natural selection when behavior within the group is regulated by a moral system or religion. Supernatural agents are an essential part of the moral system because they operate as the sanction that enforces it. Well-functioning groups coordinated by such a moral system out-compete other groups. The social coordination provided by the moral system enables groups to secure resources and other items of value that would be beyond the reach of individuals.73
Wilson’s concept draws on several works already described here, such as Durkheim’s theory of religion as the embodiment of society and Boehm’s description of egalitarianism among hunter gatherers, as well as his own research on group selection. He distinguishes between what religion achieves—the social coordination for which religious behavior was selected—and what its practitioners feel, which he acknowledges is entirely different. “Since writing Darwin’s Cathedral, I have spoken with many religious believers who feel that my focus on practical benefits misses the essence of religious experience, which is a deeply felt relationship with God,” he writes.74 But there is no necessary connection, he points out, between an end that evolution has favored and the means it has arrived at to get there. People fall in love in part to have children, he notes, “but that doesn’t remotely describe the subjective experience of falling in love.” Similarly, the experience of communing with the deity is one of many benefits that make people practice a religion.
Wilson rejects the view of many social scientists and others that belief in the supernatural and nonrational elements of religion should be seen as some kind of mental aberration. To the contrary, religious belief “is intimately connected to reality by motivating behaviors that are adaptive in the real world—an awesome achievement when we appreciate the complexity that is required to become connected in this practical sense.”
One of the ways in which religion connects to reality is through its use of sacred symbols. These symbols evoke emotions, and emotions are ancient, evolved mechanisms for motivating adaptive behavior, often doing so beneath or partly beneath the level of consciousness. “Sacred symbols organize the behavior of the people who regard them as sacred,” Wilson notes.
It’s this organization—not the implausibility of certain elements in a religion’s sacred narrative—that should be seen as the criterion of a creed’s effectiveness. The adaptedness of religious beliefs “must be judged by the behaviors they motivate, not by their factual correspondence to reality,” Wilson says.
How Religious Behavior Emerged
Complex organs like the eye or ear emerge step by step in evolution, and the same would be true of a complex behavior like religion. But there is as yet little evidence to help trace the steps by which religious behavior came into being. One question is whether religion existed before language. If belief in supernatural beings is an essential feature of religion, it is hard to see how such beliefs could have been shared before language.
But it’s possible that some proto-religious behavior existed before language, based on communal dancing and such information as can be shared through grunts and gestures. Without the use of language, an alpha male chimp, for instance, can conduct all the politics necessary to keep himself in power.
Rhythmic activity, such as dancing or marching, can induce strong feelings of togetherness in members of a group, as is discussed further in the next chapter. And humans for some reason have acquired the ability, not possessed by chimpanzees, of entraining their movements to a common beat. It seems quite possible that this ability emerged because communal dancing fostered group cohesiveness. If so, some kind of wordless community dancing may have been the first element of religious behavior to have been favored by natural selection.
Once language had developed and people were able to share precise thoughts with one another, a second element would have emerged—belief in the supernatural. There is considerable plausibility in Tylor’s argument that early peoples attached great significance to dreams, and particularly to dream time encounters with dead relatives. It would have been easy to assume that people’s ancestors had continuing existence in a supernatural world from which they exerted godlike influence on the everyday world.
Natural selection might have favored groups or individuals who practiced ancestor worship if in fact their beliefs about godlike ancestors led them to behave in ways conducive to their society’s survival. A relationship with the ancestors might have developed through the concept of reciprocity—I give you this, you owe me that in return—which is deeply rooted in the primate heritage. Reciprocal relationships with the ancestors may have seemed quite natural to early soc
ieties.
But what did the ancestors, being dead, want or need from the living? Early people had many needs, for fertility, health, good hunting, success in warfare, all of which were assumed to lie in the ancestors’ power to grant. So humanlike needs were imputed to the ancestors, whether for social respect, or for prized food such as meat. Special forms of respect—prayer and worship—were developed for the ancestors’ benefit. For donations of food, the idea of sacrifice developed. We will give the ancestors this precious gift, and they in return will grant our prayer for successful hunting, a bountiful harvest, victory in tomorrow’s battle. The gifts, if living, evidently had to be killed in order to assure immediate delivery to the supernatural realm.
Sacrifice, prayer and ritual all have the same basic purpose, that of influencing the gods’ behavior. It is easy to see how negotiation with the gods would have become a potent way of harnessing a society’s energies to achieve common goals. The gods will grant our wishes if we behave as they have commanded. But what are their wishes? Those who interpreted the gods’ intent, whether the hunter gatherer band, or the priests and rulers of settled societies, gained the power to unite their society in a common purpose, whether in standards of morality or in battle against neighboring tribes.
People and groups who were inclined to believe in the supernatural would have formed more cohesive societies and left more progeny than those who did not. A propensity for supernatural belief could therefore have been favored by natural selection.
Other genetically shaped behaviors could then have accreted around a basic belief in the supernatural, enhancing its value for survival. These would have included a propensity to fear that the gods would punish infractions of their rules and a willingness to yield one’s life in society’s defense.
This handful of behaviors provided an extraordinarily economical and effective way of evoking in early people a deeply felt allegiance to their group or tribe. The groups that made most effective use of this new human faculty prevailed over others, and the genes supporting the faculty became universal. The time course in which each behavior was added to the growing complex cannot at present be constructed. All that is known is that by 50,000 years ago, the date that modern humans dispersed from Africa, all the elements of religious behavior were in place and were inherited by all descendants of the ancestral human population.
That is the genesis of religion. But there is one essential component of religious behavior, perhaps the most magical and mysterious of all, that requires closer attention—the faculty of music. And closely allied with music is sacred dancing, and the rhythmic muscular exertions that induce trance.
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MUSIC, DANCE AND TRANCE
[Bach’s] St. Matthew Passion of 1729 ... probably brought religion home to many more souls than the words of a thousand curates. At times doctors of music have been nearer than doctors of divinity to God.
OWEN CHADWICK75
In the ancestral religion of hunter gatherers, people bound their communities together in emotionally compelling dramas of music, chant and dusk-to-dawn dances. The marathon rituals ended for some in exhaustion, for others in a state of trance that opened doors, for them and their community, between this world and that of the supernatural.
Little by little, the ancestral religion was suppressed in the settled societies that began to emerge 15,000 years ago and has survived only among the handful of hunter gatherer tribes that endured into the modern era. The new settled societies adopted a structured form of religious practice, one in which priests controlled the ritual and monopolized interaction with the supernatural. The communal dances ceased. The songs were silenced. The shamans were marginalized as witch doctors or sorcerers.
But the ancestral religion was woven too deeply into people’s behavior to disappear entirely. The vase was shattered, but its shards endured. It required an intuitive leap to recognize the pieces, see how they had once been assembled and figure out what the vessel’s purpose had been. That leap was made not by any anthropologist or archaeologist, but by a distinguished military and world historian, William McNeill.
McNeill’s epiphany came when he was drafted into the U.S. Army in September 1941 and set to marching about for hours on a patch of Texas plain. It was hot and dusty, and the exercise seemed worse than useless, given that marching in close formation on a modern battlefield within range of machine guns would have been suicidal. But all that aside, McNeill writes, marching about in step with the others somehow felt good. “Words are inadequate to describe the emotion aroused by the prolonged movement in unison that drilling involved. A sense of pervasive well-being is what I recall; more specifically, a strange sense of personal enlargement; a sort of swelling out, becoming bigger than life, thanks to participation in a collective ritual.”76
McNeill’s insight was that rhythmic muscular movement in unison had a strange and powerful effect on the emotions: it created both a sense of exhilaration and a feeling of solidarity with other participants. Group cohesion, though not well understood by many civilians, is a matter of the greatest concern to military commanders. A poorly trained group will dissolve and run when 10 percent of its men have been killed; a cohesive force will not break until just 10 percent of its members are left alive. This is a difference that decides battles.
Why should military organizations be able to evoke, by suitable training, this strange behavior of group cohesion, one that routinely prompts soldiers to the biologically irrational act of risking their lives? McNeill realized that this must be an aspect of human behavior left over from the ancestral religion. Military drill, like the religion of hunter gatherers, involves rhythmic muscular movements, performed by a small community. The transcendence of self, achieved by ritual dancers, or in the heat of battle, or to a lesser extent by hours of drilling, is somehow induced by sustained rhythmic movement. “Drill, dance and battle belong together,” McNeill writes. “All three create and sustain group cohesion; and the creation and maintenance of social groups—together with resulting rivalries among groups—constitute the warp and weft of human history.”
The strange power of strenuous rhythmic movement to bind a group together may be hard to imagine for any who have no personal experience of the effect. But there is no reason to doubt that it does so. Alfred Radcliffe-Brown’s description of how the Andaman Islanders of the Indian Ocean achieved group cohesion is worth quoting at length because it shows how people enjoy the dancing, despite its strenuous demands, and come to experience a state of “ecstatic harmony” with the rest of their community:The Andaman dance, then, is a complete activity of the whole community, in which every able-bodied adult takes some part.... In the dance the individual submits to the action upon him of the community; he is constrained, by the immediate effect of the rhythm as well as by custom, to join in, and he is required to conform in his own actions and movements to the needs of the common activity. The surrender of the individual to this constraint or obligation is not felt as painful, but on the contrary as highly pleasurable. As the dancer loses himself in the dance, as he becomes absorbed in the unified community, he reaches a state of elation in which he feels himself filled with energy or force immensely beyond his ordinary state, and so finds himself able to perform prodigies of exertion. This state of intoxication, as it might almost be called, is accompanied by a pleasant stimulation of the self-regarding sentiment, so that the dancer comes to feel a great increase in his personal force and value. And at the same time, finding himself in complete and ecstatic harmony with all the fellow-members of his community, experiences a great increase in his feelings of amity and attachment towards them.77
Not a bad way to build esprit de corps, a quality that may seem far removed from everyday life today but would have been highly relevant in small groups that fought frequently with their neighbors. McNeill is a historian, not an evolutionary biologist, but he gives weight to a factor that biologists have often ignored—the role of warfare in shaping human evolution. Early human grou
ps that instilled better cohesion in their members through ritual dancing would have survived better than their adversaries. This suggestion ties in well with the condition for group selection mentioned in the previous chapter—a high level of conflict between groups is required if group-level selection in favor of pro-social behavior is to outweigh the within-group selection against it.
McNeill also draws attention to the central issue of communication. It’s the sharing of information that binds a group of individuals together. This can be spoken information, but more important than words in the binding process is emotional information. This is conveyed by different, and probably much older, forms of communication than language. The vehicles of emotional information are gesture, such as dance, and evocative sounds, such as music, including wordless chanting and drumming.
It might seem that complex information can be conveyed only in the form of words, because that is the only way with which we are familiar. But consider the complexity of the task faced by the alpha male of a chimpanzee group. At any time he can be overthrown by a coalition of other powerful males. Yet by sound and gesture, he somehow manages to divide his adversaries and bind his allies so successfully that his reign may last many years—16 years is the longest reign on record. Evidently chimps can conduct sophisticated coalitional politics without uttering a single word.
The Faith Instinct Page 9