Placebos, Faith, and Morals

Or Why Religion


Thomas Gale Moore
Hoover Institution
Stanford University


Though I have all faith, so that I could remove mountains, and have not charity, I am nothing.

I Corinthians, xiii

Religion has an extraordinary hold on people no matter its particular rituals and beliefs. The following description of a pilgrimage to a holy site could be duplicated for most of the major belief systems:

Seeing … for the first time creates ecstasy in non-believers. It reduces believers to tears. … Pilgrims … some …in some dream-like world; still others unconsciously weeping tears of ecstasy. (Ahmed 1988, 144-45)

The author is reporting on a visit to Kaaba, the most religious site in Islam, but the account could be that of a devout Catholic on a pilgrimage to Lourdes, or an Orthodox believer hiking up Mt Athos in Greece, or a Hindu journeying to the Ganges.

According to ethnologists, every society has had a form of religion. Of the more than 300 societies listed in the Ethnographic Atlas, 98 percent have religious beliefs that incorporate an afterlife (Hull and Bold 1994, 456). Such an ubiquitous phenomenon requires explanation, especially since our closest living relatives, chimpanzees, show no evidence of religion or spirituality. Neanderthals, with whom we have a common ancestor who lived about 690,000 to 550,000 years ago (Klein 1999, 507), have left few artifacts that could be construed as art or that exhibit spiritual or religious motifs (Klein 1999, 439-442; 469-70). We are the only species that is religious and we tend to be very religious. To be religious remains one of the strongest impulses exhibited by Homo Sapiens.

Roughly 40,000 years ago, human beings began to make a wide variety of objects, many of which, beautifully decorated, appear to be religious or spiritual in nature. During this same period, approximately 40,000 to 50,000 years ago, a number of paleoanthropologists believe neural changes brought on by evolutionary pressure led to changes that made for modern social man (Klein 1999, xxiv). Perhaps the ability to use language propelled humans into the modern world of innovation, elaborate societies, and religion. It seems, though, that logic and speech could have evolved independently without generating spirituality or religion.

Explanations for Religion

Common "explanations" for religion include: providing a moral framework for the workings of society; offering explanations for the universe, the weather, chance occurrences, and sickness and death; providing comfort to those bereaved. Although religions typically furnish those benefits, these rationales fail to explicate all religions or all religious experiences. Indeed in some situations or societies, religion fails to offer one or more of such benefits.

It is important not to equate Christianity with religion. There are and have been many other religions in the world. The table below lists the current major belief systems; Christians make up about a third of the world’s population. One in five people on this planet worship Allah. However only 2.5 percent profess to be atheists and another 12.8 percent claim to be non-religious. Nevertheless, 85 percent of the globe’s population profess some form of faith. Many of the others may have adopted secular religions such as Communism, Scientology, or a worship of nature.

Religion Induces Moral Behavior

In both the Wealth of Nations and in The Theory of Moral Sentiments (Anderson 1988,, 1069), Adam Smith claimed that "one of the most significant functions of religious belief was to provide strong incentives to follow moral strictures that helped to support civil society, that is, honesty, benevolence, restraint from violence, and so forth." Smith believed that the concept of God acted to enforce moral conduct. However, religion is neither necessary nor sufficient to induce moral behavior. Atheists are often very moral people while churchgoers have been known to sin.

Since only half of the societies catalogued by anthropologists include an afterlife that rewards or punishes behavior in this world (Hull and Bold 1994, 456), evolution is unlikely to have developed religion as a means of inculcating moral rules. Nor do all religions offer consistent cosmologies. Buddhism provides mainly a road map for escaping life and its sorrows while supplying little comfort to those who have lost loved ones. In fact, Buddhism and Jainism have been described as atheistic religions because they do not postulate a god (Durkheim 1899).

Adam Smith also argued that religion established a mechanism for guaranteeing reputation and moral certitude. As Smith pointed out, religion can enhance reputation, which can be a strong force for assuring cooperation. Acting "Godly" or being a devout member of a religion can promote a belief in a person’s moral character.

Religious Adherents Worldwide 1998

Major Religions

Number (millions)

Percent of World Total




Roman Catholics















Chinese Folk Religionists






Ethnic Religionists



Non-religious and Atheists



Statistical Abstract of the United States 1999, Table 1348.

Religion Explains the World

Religion is often seen as providing an "explanation" for natural phenomena that primitive people found miraculous or inexplicable. This hypothesis, however, fails to elucidate why in this modern age – a period in which science has removed most of the mystery of the origins of life or the causes of natural occurrences – religion persists. According to the Gallup poll, nine out of ten Americans believe in God; eight believe in a heaven and hell; seven believe in life after death (Reeves 1996).

On the other hand, two polls of scientists, eighty-one years apart, found that about 40 percent of those learned individuals in both periods believe in:

"a God in intellectual and affective communication with humankind, i.e. a God to whom one may pray in expectation of receiving an answer. By ‘answer’ I mean more than the subjective, psychological effect of prayer."

(Larson and Witham 1997)

The proportion of biologists, physicists, and mathematicians who believe in this very personal god has changed very little despite the tremendous growth in knowledge about the origins of the universe, the development of life, and the evolution of humans. Over one-in-five physicists and astronomers still believe in this personal God. On the other hand, a belief in human immortality fell from 51 percent to 38 percent over the period and a desire for immortality plummeted from 34 percent to 10 percent.

Although 39 percent of scientists in the United States expressed a belief in God, among those who were members of the National Academy of Sciences, just 7 percent held such a belief (Larson and Witham 1997 & 1998). An advanced education in science evidently erodes belief, but the current state of the public’s knowledge has little effect. Religion still dominates. Only the elite of those that make a living in science have largely forsaken religion.

Since the public’s knowledge about nature has failed to weaken religious belief and religion has such a strong emotional hold on most humans, its origins must stem from other factors. Although some have argued that religion is simply a product of culture, its ubiquity and power suggests that the need for a faith is part of human nature. If it were simply a product of culture, some human groups would exhibit no religion. The form religion takes is clearly culturally determined. In that respect it is similar to language. All humans have an instinct for language (Pinker 1994), but their culture determines the language children actually learn. Given its universality and the evidence that all human societies in the past incorporated a religion, the urge to believe must be in our genes.

Definition of Religion

Faith consists in believing when it is beyond he power of reason to believe. It is not enough that a thing be possible for it to be believed.
Voltaire,Questions sur l’ Encyclopédie


The American Heritage Dictionary defines religion as: "Belief in and reverence for a supernatural power or powers regarded as creator and governor of the universe." The operative word is "belief." Even though we have made great progress in explaining nature, storms, disease, and even death, people still have strong beliefs about supernatural powers that control these events.

Belief lies at the core of religion. Orthodox Jews, for example, define their religion in terms of belief. You must believe … in order to be a "believer."

Faiths usually offer more than simply a belief. Typically they involve special rituals, sanctuaries, and they employ certain specialized individuals to lead the group. Normally they require a belief in one or more supernatural powers that can affect the lives of the followers. This spiritual being or beings is often called upon to defend, to help, and to divert tragedies or to provide some special dispensation.

Most creeds offer surcease from fear – fear of the unknown, fear of nature, fear of sickness, fear of death – and from the grief over the loss of dear ones. Love is a strong emotion designed to weld mates and to promote bonding between infants, children and their parents. When death of a loved one devastates a person, by promising an afterlife religion provides much needed solace. Giving people sympathy and reassurance that they will see the departed again strengthens their faith and willingness to meet the ethical goals the religion fosters.

Religion also relies on symbols, pageants, music, and rituals to reinforce allegiance to the faith. As Pavlov demonstrated, humans and other animals can be trained to respond to arbitrary stimuli relating to fear and hunger. The same learned reaction appears to occur with other emotions. A snippet of song connected with one’s youth, courtship, or family, for example, may bring a feeling of nostalgia. A religious chant, a prayer, a particular service may evoke a feeling of awe, ecstasy, or unity with the world. The need to bond and the fear of the unknown, combined with symbols triggering devout feelings, may work together to create superstitions, cults, and religions.

Although everyone would agree that Buddhism and Jainism are religions, the practitioners do not worship a God or other supernatural power. Like Jainism, Buddhism does not believe in a creator, but unlike Buddhism, Jainism believes in a soul. On the other hand, Hinduism, from which both Jainism and Buddhism derived, holds that Lord Bramha created the world. All three religions contend that people are reborn until they reach some state of peace, Nirvãna, that removes them from the wheel of life. Nevertheless, all three of these faiths are religions. They include a belief system.

In a similar fashion Scientology does not propound any supernatural being that rules the universe. Communism has often been considered as having religious aspects. All these doctrines have in common a belief system around which their practitioners build their lives.

Moreover, they have faiths that facts cannot shake. The fall of the Soviet Union, for example, failed to discourage real believers in Marxism either in the West or in the former Russian empire. Failure of a religion to deliver leads some dedicated practitioners to take the view that their faith or their practice has not been pure enough. Apologists for Communism claim typically that it has never been properly tried.

Over the last three millennia, this phenomenon of blaming disaster on the lack of fidelity to religious dogma has been common. When Jews found themselves losing battles or being subjugated by the Philistines, a common reaction was to see God as punishing them for contravening His commandments. When the Byzantine world was rolled back and faced with an enemy – Islam – that seemed unstoppable, the Orthodox explained the failure of their God to protect them by their deficiencies in following His dictates strictly. It is ironic but understandable that today the movement towards strict Muslim conformity is a reaction to the strength of the non-Islamic West.

Some people, if not all, have a belief system that orients them toward the world. As an economist, I have known colleagues who structure their lives around "the market" as something sacred and the source of all that is good. As indicated, others – Communists –believe that "the market" is the source of all evil. Many scientists believe that science is a fundamental creed that explains all. Evidence can influence most of these researchers but often a compelling case fails to shake their belief. Religion then is far from a unique structure of belief but one that melds into a more open value system. Evidence, logic, or rational discourse cannot move a very religious individual from his or her beliefs. For example, in spite of all the scientific evidence, many fundamentalists believe that God created the earth a few thousand years ago and deny that evolution led to human beings.

Organized religion is simply one, albeit the most visible and common, form of belief. At its heart typically, but not always, are supernatural beings. Modern mainstream religions, such as Episcopalianism, have moved away from such beliefs without denying them completely. Nevertheless, almost all religions continue to rely on non-material beings or forces. They require belief.


Beliefs also play a strong role in medical care. Scientists have found that if a patient believes that a treatment will be effective, it often produces results, even though by objective standards the therapy is useless (Blakeslee 1998; Brown 1998). Science writer Sandra Blakeslee gives examples of placebos making hair grow, increasing the lung function of children, mimicking poison ivy, leading to knee pain relief after feigned surgery, and inducing pain from expecting a heavy object to be dropped on their foot. She tells the story of an individual with cancer diagnosed as having only days to live who, believing an experimental drug would help, experienced a miraculous shrinkage in his tumor. Upon reading articles throwing doubt on the treatment, he had a relapse until reassured by his doctor that the drug was effective. Two months later, after reading a definitive article reporting the drug was worthless, he died.

According to Margaret Talbot, writing in The New York Times Magazine (January 9, 2000), the placebo effect benefits between 35 and 75 percent of the patients taking dummy pills in studies of new drugs. She reports on a small study in which patients who received fake arthroscopic surgery on their knees for arthritic pain experienced reduced discomfort. A Seattle cardiologist tested a common procedure for angina that involved opening the chest and tying knots in two arteries. He compared the normal results – 90 percent of the patients reported benefits – with fake surgery; the placebo operation was just as successful. Doctors have eliminated warts with bright dye and improved breathing for asthmatics with a fake bronchiodilator. Talbot quotes one doctor, Nelda Wray, in charge of health care research at the Houston Veterans Administration, as claiming "The bigger and more dramatic the patient perceives the intervention to be, the bigger the placebo effect. Big pills have more than small pills, injections have more than pills and surgery has the most of all." Alternative medicine, such as homeopathy and acupuncture, may depend on the placebo effect to achieve real improvement for their patients.

Up until the 20th century, doctors really relied on the placebo effect to generate cures. Placebos do not have to be pills or injections: in many cultures they can be dances by the medicine man, potions provided by the village shaman, or visits to holy sites. The actual belief makes no difference. It can be that a man in a white coat with a stethoscope around his neck will cure you; it may be that a voodoo priest casting a spell will cast out your sickness; you may believe that prayer can remove your malady; it could be that a charismatic individual will provide you with life’s answers. If someone believes in voodoo, a doll with his/her likeness may bring sickness or even death. Belief is very powerful and, as careful studies have shown, is remarkably effective.

It can also produce strong negative effects, sometimes called mass sociogenic illness or, more commonly, mass hysteria. A belief that some thing, person, or spirit is causing sickness often does result in pain, suffering, and symptoms of illness. As Dr. Dean Edell describes it, "Many of the diseases … have taken on cult like status. Patients approach those illnesses with a religious fervor that defies explanation."(1999, 36)

Medieval Europe witnessed a malady called Tanzwuth which led sufferers to wild dancing, seizures, and, eventually, fainting. In a recent example, described by Edell, students in a high school class were told that a safe, nonvolatile herbicide had been sprayed near the school. Although the story was complete fiction, thirty-two students had to be rushed to hospitals. In another school, a student claimed that cocaine had been baked into a white cake. Even though subsequent analysis showed that he had made up the story, twenty-two kids fell ill and were rushed in three ambulances to the hospital. Even though considerable controversy remains about whether chemical exposures caused the Gulf War syndrome, the symptoms are consistent with mass sociogenic illness. What seems to be crucial in such hysteria is a belief that the person has been exposed to a substance that could cause harm.

The Placebo Effect of Religion

Since belief systems are so powerful, belief in a religion can provide real physical and health benefits (Johns Hopkins Medical Newsletter, Nov 1998). As Blakslee reported, a strong belief has physiological effects. Numerous studies have found that faithful churchgoers, believers, and those with strong religious leanings live longer and are healthier than those who are more skeptical (McFarling 1998 & 1999; Strawbridge 1997; Koenig et. Al. 1997; Oxman et. al. 1995). Those benefits exist even after taking into account the more sober lifestyle of many religious adherents (McFarling 1999).

Such evidence suggests that belief and, therefore, religion, is beneficial from an evolutionary fitness approach. However, although belief in religion may increase fitness, that fails to explain why evolution should have beings that could be more successful if they had a strong faith. Why should evolution favor those who believe over those who are more skeptical? The answer would seem to lie in the importance of religion in fostering ethnic solidarity.

Ethnicity and Religions

Most religions are unique to a tribe, a small group of tribes, an ethnic group, or a nation. Even modern religions tend to be area-specific; the United States and other immigrant-built societies are the exception.

Religion probably arose, at least in part, as a mechanism to foster group solidarity. As Herbert Simon noted: "Beliefs about rewards and punishments after death, which are present in one form or another in most religions, provide an important example of the support of altruism…"(1992, 76). Faith can strengthen an ethic of aiding others, especially those who are in the group, that is, the tribe, congregation, or nation. If religious dogma induces all members of the tribe to help each other, their genes may be passed on in greater numbers than those of competing tribes that have failed to develop strong group bonding.

Members of religious groups often refer to other believers as "brothers" or "sisters" and to the leaders of the faiths as "fathers." God is often referred to as "Father" or in this day "Mother." Tying adherents together with family terms strengthens the bonding. The closest ties people have are to family members, such as those whose names appear in religions. In the same vein, patriots use the term "fatherland" or "mother Russia."

Christianity included, religions virtually always stress the difference between the in-group and the heathen. Only in recent times has the murder of people from other tribes or religions been considered wrong. After Joshua slaughtered the women, children, and men of Ai, he built an altar to the "Lord God of Israel" and "wrote there upon the stones a copy of the law of Moses," including the prohibition "Thou shall not kill." Since the people of Ai were not part of the chosen people, Joshua was not being hypocritical. Margaret Mead made the same point: murder is considered wrong only when it involves a member of one’s own tribe (Ridley 1997, 192).

Modern religions that encompass many ethnic groups and hold themselves out to be universal probably result from the competition among sects for members. Universal religions lose some but not all of their ability to motivate narrow ethnic groups but gain by solidifying larger groups. These proselytizing religions, such as Christianity, Islam, Buddhism and Jainism, claim that they minister to all irrespective of their ethnic origins and are thereby truly universal.

Christianity and Islam were derived from Judaism, which does not encourage converts. A version of Judaism, such as Christianity or Islam, that actively seeks converts became a very effective ideology that could unite disparate peoples, especially the downtrodden, who gained little from the then major faiths. Similarly Buddhism, Jainism, and Sikhism were derived from Hinduism, which again represents an ethnic or cultural group but was and remains hostile to converts. Neither the derivative faiths of Judaism nor the derivatives of Hinduism were able to make much progress in converting adherents to their ethnic based origins. Jews failed to convert to Christianity or Islam; Hindus failed to convert in large numbers to Buddhism or Jainism and those that did were lower caste individuals who suffered under Hinduism. Nevertheless, as the table on Religious Adherents shows, the proselytizing/universal religions of Christianity and Islam have converted over half the world’s population.

During the early centuries of the modern era, Christianity was competing with other mystery religions for dominance. Each offered an afterlife, which tended to make soldiers more willing to take chances and risk their lives. Each offered rewards for good behavior, usually described as supporting its "God" in his/her struggle against the enemy. Around the turn of the first millennium, when Scandinavia was converting to Christianity, leaders adopted the new religion because it strengthened the loyality of their troops and their willingness to fight (Reston 1998). Certainly one of the reasons that the Muslims riding out of the Arabian desert were so powerful was their great faith in Allah and his promise of everlasting paradise.

The tremendous need filled by the Church, the Synagogue, the Mosque and the Temple is almost surely connected with the evolution of group loyalty. A shared feeling of awe of a supernatural force, combined with common ceremonies, rites, music, and art, can strengthen group solidarity. Sacrifice to a being special to the congregation may reinforce a collective inner experience. Pageantry, music, and rituals – all work to intensify a feeling of transcendence. The great importance of reinforcing group solidarity may explain the origins and development, not only of religion, but of art and music, which appear to have grown up with the former.

Evolution seems to have provided a real reward for those who have faith. People who believe live longer, express greater satisfaction with life, and are healthier than non-believers. The placebo effect may have evolved simply to strengthen the survival of those who believed and could therefore be counted on to sacrifice for the tribe. Those with religion lived longer and passed on more of their genes, including the gene or genes to believe. Non-believers were shunned, not trusted, and lived shorter lives, resulting in fewer offspring.

Group Loyalty

Religion plays a strong role in strengthening group solidarity. Many people have pointed out that a group that works together, whose members help each other, is much more likely to remain together in times of trouble. Altruistic acts foster unity and cohesion. By tying individuals together and by requiring individuals to behave in ways that help the group, religion promotes group loyalty. It also makes it easier to identify those who are loyal and those who may cheat.

Economists, in particular Jack Hirshleifer (1977) and Herbert Simon (1992), and evolutionists, Robert Axelrod (1984); Robert Wright (1994); Matt Ridley (1997), have postulated that altruism could spring from reciprocity. Reciprocal altruism, however, suffers from the "free rider" problem. If others are generous, cheating or failing to reciprocate bestows an advantage on those who do not respond in kind. Some have argued that altruism increases the fitness of the species, but others have noted (Dawkins 1976; Wright 1994) that free riders would destroy the universality of such altruism. As the selfish prospered at the expense of the altruistic, selfish genes would increase in relation to altruistic ones, even if the species as a whole were better off by being altruistic. As a consequence, most modern evolutionists reject arguments based on the fitness of the species to focus on the fitness of the individual. Indeed Richard Dawkins (1976) has shown that only the individual or the individual’s genes matter.

According to Axelrod (1984 & 1987), a political scientist, reciprocal altruism is an efficient strategy in situations where individuals will interact over some unknown period of time. His research on game theory has demonstrated that in such cases reciprocal altruism is a stable and robust long-term solution to the prisoner’s dilemma game (Wright 1994).

Axelrod’s work, based on an iterative game, indicates that a Tit-for-Tat (TfT) policy –being "nice" on an initial interaction with a strange individual with whom one expects to have frequent future relations and then simply repeating the moves of the other player – can in many cases prove to be the the most advantageous long-run strategy. TfT mimics the biblical "an eye-for-an-eye," "a tooth-for-a-tooth," but seasons it with generous measures of forgetting and forgiving. Assuming that the iterations go on for an indefinite time and that the discount rate is not too high, the strategy is stable and brings the best rewards over an extended period.

Although reciprocal altruism (Ridley 1996; Axelrod 1984; Wright 1994) provides a basis for building a moral code, it breaks down all too easily. Misunderstandings can lead to feuds, that is, to reciprocal violence. Reciprocal altruism also fails when a game is known to have only a single round or to be ending. In those cases the stable solution is for both parties to defect.

Even though reciprocal altruism may explain much obviously altruistic behavior, many clear cases of generosity occur that cannot or will not be reciprocated. People give anonymously to various causes. The secret benefactor may be rare but he exists. Some provide help to others whom they know will never be in a position to respond.

Consider two primitive hunters, one of whom is attacked by a wild and ferocious animal, perhaps a saber-toothed tiger. The second person could come to the aid of his partner but only at some risk to himself. If he simply runs away, he lives to spread his genes; his dead partner cannot retaliate. If he helps, both may survive, although the helper runs the risk of being killed as well. To maximize his fitness, the second hunter should run from the scene. Often however he remains to support his partner.

Wars between tribes can also result in situations where self-preservation may be preferable to aiding a colleague. A tendency to run, however, will reduce the long-run fitness of members of the tribe. Those tribes that work together and fight together are likely to win. Religion can provide the glue that holds the group together. If faith in common gods and rituals can generate a moral feeling that encourages bonding and tribal solidarity, members will be more likely to take risks to help each other. In 1958 Paul Samuelson made this point (481):

But culture in which altruism abounds – because men do not think to behave like atomistic competitors or because men have by custom and law entered into binding social contracts – may have great survival and expansion powers.

Benefits of Groups

Geese and ducks fly in flocks, often traveling in military procession; many types of fish swim together in large schools; bison, antelopes, and giraffes travel in herds. Animal species that are subject to predation find safety in numbers. Trivers (1985) reports, for example, that the probability of a single wood pigeon’s being eaten by a goshawk falls from 20 percent to 0.2 percent when it is with fifty other pigeons. Moreover, a group working together, such as a wolf pack, can take on a prey much larger than itself. Virtually all the predators that feast on larger animals hunt in packs (Wilson 1978, 84).

Anthropological evidence does show conclusively that, like other major predators, proto-humans hunted in packs (Wilson 1978, 84). They, too, preyed on much bigger species. To this day pygmies hunt successfully much larger animals than themselves, including elephants (Cavalli-Sforza 1995, 1-2). Although the occasional lion may have feasted on the odd solo man, humans or even early hominids had little to fear from predators.

Humans congregate in tribes. A few stray males may become hermits, but the nuclear family cannot easily survive by itself. The human species is gregarious and social. For our species and for many others, there is safety in numbers. Being a member of a tribe increases individual fitness. Groups provide safety for their members in at least two important ways (Dunbar 1996, 17-18). The larger the group, the more eyes and ears are available to detect predators. In addition, predators attacking a large herd can easily become confused over which animal to chase. If the prey are numerous enough, they may even be able to fight off the predator. If the attackers are another human tribe, the larger group is likely to survive and pass on its genes.

Early man was both a predator and at times a prey. Lions, tigers, hyenas and other large carnivores sometimes dined on our ancestors. Proto-humans also preyed on smaller animals or scavenged. Groups of those hunter-gatherers had a much higher success rate than any single individual would have had. Although early men must have feared attacks by lions and other larger predators, their chief threat probably came from other hominid tribes. The larger the tribe, relative to others, the more secure its members and the greater its ability to maraud, conquer other tribes, or steal females successfully. Larger groups, however, are less stable than smaller associations. Consequently evolution would favor mechanism, such as religion, that would help promote group loyalty.

History does show that humans evolved over time to live in larger communities. Anthropologists have reported the growing size of the average community over long periods. On average Australopithecines lived in groups of 67 individuals; Homo habilis groups numbered about 82; H. erectus tribes consisted of 111; H. sapiens communities contained 131; the Neanderthals lived among 144 others of their kind; modern human tribes number 150 (Mithen, 133). Many modern hunter-gatherer societies involve tribes of one or more thousand (Cavalli-Sforza 1995, 5).

Drawbacks of large groups

Why should our ancestors have tended to congregate in larger and larger groups? Size would bring significant problems. The larger the group, the more difficult it would be to find food. Large groups have greater sanitation problems. The larger the group, the more likely that disease would spread through the population.

Even more fundamental, as its members became more numerous, counting on each individual to work in the common interest would become more difficult. Free riders would be harder to detect. In general, building significant coalitions to promote one’s interest poses increasing problems when there are many competing individuals than when there are few.

Genetic linkage provides at least a partial solution. Indeed ecology shows that most social species are either closely related genetically, like ants, or are collections of relatively few individuals. Holding a large group of unrelated individuals together requires either a genetic connection or some mechanism that generates a loyalty to the group. Religion furnishes that mechanism.

Evolutionary Pressure towards Larger Groups

As we know from recorded history and from anthropological records, humans have always preyed on other humans. As Wilson notes: "Intertribal aggression, escalating in some cultures to limited warfare, is common enough to be regarded as a general characteristic of hunter-gatherer social behavior." (1978, 82) This aggressive behavior appears to stem either from a need for more territory and valuable food resources or from a need for women. As the number of individuals grew in a given area, the pressure to find more land or to displace other humans from the territory grew as well. Edward O. Wilson reports that the Mundurucú headhunters emphasized the glory of killing members of other tribes (1978, 112-113). The tribe and its members achieved fitness benefits from fewer competitors for the limited game in the area.

According to prevailing scientific opinion, humans originated in Africa and probably migrated out about 40,000 to 50,000 years ago. Prior to that migration, Africa had apparently gone through an arid period, brought on by the initial glaciation after the Last Interglacial, leading to a significant reduction in population (Klein 1999, 437). As the climate dried up and our ancestors had to search farther for food, often unsuccessfully, wars between tribes over waterholes and access to game must have become vicious. Only the larger tribes could survive, putting a premium on developing or evolving skills and traits that would promote solidarity. Language and religion, both of which would help hold together a larger group, may have been the result.

Pressure existed even during better times to raid other tribes. Although as many females are born as males, women can become a limited resource. Wilson reports that "One-quarter of all Yamanomamö men die in battle, but the surviving warriors are often wildly successful in the game of reproduction."(1978, 115)

Human beings are a mildly polygamous species. In most societies successful males have monopolized more than one female. If some males have possession of more than one female, other males will have access to none. This implies genetic death and most males will become aggressive to acquire a woman or women. To those who have monopolized one or more women, the celibate males constitute a threat. Within a tribe they are generally a destabilizing force. Consequently, if a tribe can secure additional women by raiding other tribes, it can enhance its own stability and the fitness of its members. In addition, the leader of the tribe can enhance his access to women. The founder of one block of Yamanomamö villages had 45 children by eight wives (Wilson 1978, 115).

Christian G. Mesquida and Neil Wiener found that the higher the percent of young males aged 15 to 29 in a population, the greater the severity of conflicts (1996). Deaths per million over a ten-year period were correlated with the percent of the youthful population. Despite the rough parity between the number of young men and women, the women tended to marry older men with more resources, leaving their male contemporaries without the prospect of mates. Consequently they were often willing to fight to achieve either resources or women. Tribal leaders, faced with unrest by such males, will often welcome military action.

Daniel Kriegman and Orion Kriegman have argued that conflict between groups of humans led to the evolution of a propensity towards religion. In, "War and the evolution of the Human Propensity to Form Cults, and Religions," a paper presented at the Human Behavior and Evolution Society’s annual conference (June 1997, Tucson, AZ), they addressed the question "Why Religion?" They concluded that human evolution, particularly cognitive skills, has been driven by selective pressure to form social alliances for aggression. As they put it, "All other things being equal, the largest army wins." Or as Voltaire wrote (1770): "God is always for the biggest battalions." This puts strong pressure on adaptations promoting greater unity within larger groups, such as those provided by cults and religions. Religion ties an ethnic group together for warfare by means of an "in-group morality" and "out-group brutality." Moreover, by reducing anxiety about death, religion makes troops more willing to fight.*

Since large groups were more likely to be victorious in war, they had greater reproductive success than smaller. Evolutionary pressure thus developed to insure the social coherence and sustainability of larger groups. As mentioned above, a large group has greater problems of coordination and of maintaining social cohesion. If the tribe itself is to be viable, all members must work together, especially when the group is threatened. Free riding would be a major problem, making religion important in identifying slackers and holding the others together.

Group Bonding is Everywhere

Tribal bonding is ubiquitous. Herbert Simon (1992, 77) points out "the central role in economic behavior [of] group loyalty." He (1992 and 1993) notes that business firms are more than a collection of independent, selfish individuals; the employees usually identify with the goals of the organization and are loyal to it. In the modern world, outside the marketplace, bonding can take the form of loyalty to one’s school and its football team, adhesion to a military unit, fealty within clubs, ethnic and religious solidarity, and language group attachments.

Groups can be any identifiable set of peoples, clans, tribes, clubs, religions, nations, ethnic groups, speakers of a language, organizations, such as businesses, professions, or specific trades. People can and usually do belong to more than one group. Humans build loyalty to those coteries and can often be called upon to help the association or people involved with the group. The wider, the more open, the more general the group, the less will be the loyalty to the group. Closely-knit cliques with features setting them apart from others are more likely to claim great solidarity than a multi-ethnic society, such as the United States. Paradoxically much of what is good about human society and what is most damaging arises from group loyalties.

The Evolution of Group Loyalty

Would such bonding be stable evolutionary? That is would the free riders leave more heirs than those who bonded with the group. Evolution works at the individual level, not the group level. Samuelson (1993) proves that in some circumstances group selection can overcome prejudicial individual selection. Bonding with others appears to be one of those cases. Social species, such as ants, most primates, lions, wolves, and birds, show that associating increases the probability of each member’s passing on his or her genes. Consequently, to the extent that evolution can promote close association, especially with larger aggregations of individuals, it can increase individual fitness.

Group loyalty could easily have evolved from loyalty within a family, which then expanded to include a larger group, the whole tribe, some or many of whom would be related. Since evolution would have difficulty in programming people to distinguish kin from non-kin, being inclusive of the entire tribe would be a simple step. At the same time, if loyalty applied to everyone within the group, it would increase fitness for all members of the tribe. While evolution might predispose people to bond, the group with which they affiliated would have had to be learned. Bonding can, therefore, occur among virtually any collection of people who share a common purpose or relationship.

Elliott Sober and David Wilson argue that group selection can play a role in evolution (1998). According to their analysis, if altruistic behavior enhances the reproductive success of a tribe (group) enough and if tribes recombine regularly, altruistic behavior can spread. Take two groups, one of which is made up mostly of altruists and the other consists of selfish individuals. If the altruists benefit their group so that the group as a whole produces more offspring than the selfish group, then, even if in both groups the proportion of altruists declines, the total number and percent of altruists in the population as a whole may increase. At the end of this period, if the altruists coalesce to form a new group with the same benefits for all, altruistic genes can spread in the whole population. Thus group loyalty, which requires unselfish behavior, could become more common. (See the Appendix for more details and an example).

Factors Which Reinforce Group Bonding

A number of related practices can also strengthen group loyalty. As Dunbar points out, making it costly to join a coalition can minimize free riding (1996, 45). Leaving the group will then mean abandoning his or her previous investment and requiring a new investment with a new association. Although economists often argue that "sunk costs are sunk," men and women seem reluctant in practice to ignore prior investments.

Whenever group loyalty can be tested or measured in advance, the solidarity of the association is likely to be stronger. If bonding rituals are frequent – as they typically are in religious rites – individuals showing a high degree of tribal solidarity win status while slackers suffer shame or ostracism. Since status pays in terms of fitness, the evolutionary incentive will be to conform and show their solidarity. Those who are pious and follow the local religious ceremonies can easily be identified. Conversely nonconformists will be obvious and likely to attract less desirable mates. Females will avoid mating with men who fail to show sufficient group solidarity. If a woman’s mate should fail to help the tribe in times of emergency, her kin and her genes, as well as unrelated individuals, would probably suffer.

Free riding, that is, associating with the group but undercutting them when it pays, is always a danger; but losses from leaving or betraying the group strengthen solidarity. Virtually everyone, from children to criminals to nations, considers betraying the group a very serious sin. Evolution has instilled in humans a strong abhorrence and anger at those who are disloyal. Even those people who quit a business and move to a competitor face the charge of betraying their former colleagues and are likely to find themselves ostracized by their previous business acquaintances.

A recent story in The New York Times (December 13, 1998, 4) reports a horrifying example of revenge for lack of loyalty. A former guerrilla of the Kurdistan Workers Party (P.K.K.) had quit the rebel movement. A group of his former comrades went to his home; failing to find him, they killed his mother, and five brothers and sisters, age 4 to 13. Guerrillas are required to commit themselves to serve until ‘victory or death.’

Group Identification

The use of symbols and rituals appears to strengthen bonding. College teams have mascots, school songs, school colors. The military parades in uniforms, carries flags, plays martial music. As Ridley notes, "Hymns, football chants, national anthems, military marches: music and song were probably associated with group-defining rituals long before they served other functions."(1997, 190) Clubs have initiation rites, secret passwords, rituals, and sanctuaries to which access is restricted. Religions have rites, gods, buildings or places that are sacred. Ethnic groups have customs, clothing, dances, and practices that set them apart from others. Skin color, the shape of the eyes, and other identifiable physical traits can be the basis for a strong association. Unfortunately, as noted, bonding tends to result in an "us versus them" mentality, the cause of much of the strife in the modern world.

Language can be a strong mechanism for bonding. Each tribe can and often does develop its own dialect. Dunbar indicates that "someone who speaks in the same way as you do, using similar words with the same accent, almost certainly grew up near you, and at least in the context of pre-industrial societies, is likely to be a relative."(1996, 168) Identifying membership in the tribe is made easy. A person listening to a speaker can know easily whether he or she belongs. Such tests have often been used in wartime to identify spies: they fail to pronounce correctly certain words, names or terms. During World War II a German ignorant of "Dick Tracy" was correctly identified as a spy.

Developing new speech styles, strange terms, or unusual ways to pronounce words provides a mechanism for identifying membership. The foreigner, never trusted, can be recognized easily. In this context, the development by inner-city African-American teenagers of a dialect – Ebonics – is understandable as a means of building and assuring group loyalty. Its purpose was to make it more difficult for members to leave the group and to separate the in-group from the rest of society.

Most closely-knit cliques make membership expensive in order to make leaving the association costly. Hassidic Jews, for example, require adherence to a strict dress code, as do Mennonites, devout Moslems, Buddhist monks, Catholic nuns, and the military. Such trappings, by making the wearers distinctive, reinforce the sense of exclusivity. Social intercourse becomes confined to those who are members. Resigning or leaving the order implies giving up those relationships and may well result in severe penalties, especially since the remaining members will consider the renegade a traitor.

External Afflictions

Anyone who has lived through a natural disaster, a major emergency, or a significant threat to life and property knows that, during the time of strife, an extraordinary feeling of solidarity and willingness to work together develops. People who have experienced such crises often treasure this sentiment and regret the inability to maintain it. That feeling is obviously fitness enhancing. It stimulates people to subordinate their usual emotions and to work for the common good, thus protecting the tribe or group.

Hostility from the outside also strengthens the group’s internal cohesion and bonding. The bombing of Serbia fortified support for President Slobodan Milosevic; even his political opponents in Belgrade rallied round. In Iraq, American attacks have reinforced Saddam Hussein. Such reaction echoes a much earlier time. Whenever a threat from outsiders developed, the fitness of a tribe would be enhanced if its cohesion were strengthened.

Threatening a faction strengthens its members’ loyalty. The threat need not be physical; it can even be the menace of assimilation into a larger culture or the absorption of one’s own heritage into that of the more dominant culture. Since group solidarity makes for an us-versus-them mentality, a clique that makes itself more distinctive increases the likelihood that others will discriminate against it. Although the unusual group naturally deplores and objects with justice to such behavior, the discrimination strengthens the feelings of being threatened and increases the solidarity of the group.

A number of American Jews have been worrying that too many fellow Semites have been leaving the faith or neglecting its rituals (Scheinin 1998). As MacDonald (1994) points out, Jews have for several millennia managed to maintain their tribal identity and social cohesion. Jewish religious practices appear designed particularly to maintain in-group breeding and prevent conversion to Christianity or other faiths. Discrimination, periodic pogroms, and of course, in the twentieth century, the Holocaust threatened and killed Jews; in the process they fortified a natural group loyalty and a feeling of separatism. As Richard Scheinin (1998) writes, the decline of anti-Semitism in the United States has led to a 50 percent rate of intermarriage and a real fear of being swallowed up by the surrounding culture. After centuries of being a separate tribe surviving in a hostile environment, Jews are now seen as another ethnic minority, little different than the Mennonites or the Mormons.


Group identification and loyalty may also explain altruistic acts that cannot be related to reciprocal altruism. Secret donations to further a coterie’s interests, self-sacrifice, and the paradox of voting (Simon 1992) may all result from group loyalties. It is impossible to consider voting a rational economic action. As we all know, voting costs something, a little time at the least. Since the probability of affecting the outcome is very close to zero, why vote? If one votes, why vote for higher taxes? Group loyalty, however, may induce people to go to the polls and lead them to vote, not for the narrowest of their interests, but for what is, in their view, in the interests of their group.

Clearly group loyalty results in both great good and great evil. Non-members are suspect. Other tribes, other ethnic groups, other religions can and should be shunned. Even in societies like the United States, which emphasizes inclusiveness and non-discrimination, people tend congregate with fellow ethnics. In multi-ethnic schools, Blacks will eat with other African-Americans, Asians, with others whose families came from across the Pacific, Hispanics, with those whose ancestors grew up south of the border (Garcia 1999).


From the viewpoint of increasing fitness, that is, passing on one’s genes, being able to make war or to repel aggression required larger and unified tribes. A need to bind people together in larger aggregates then drove the evolution of traits that promoted group loyalty. Religion, especially early religions, served not only to bring people together but to give them assurance that they and their families would survive, either in this life or in one to come. A belief that one’s God(s) had chosen one’s own tribe gave members the strength to face overwhelming odds, with the result that they sometimes turned back less dedicated opponents. Moreover, religion and its constant demands facilitated the identification of potential free riders, strengthening group solidarity.

Only as religions evolved and began to compete for members did universal religions develop and spread. The leaders of new religions vied for membership. Those creeds offering more inclusive doctrines tended to prosper. To make their religions universal, church leaders needed to promote universal values. "Thou shall not kill one’s neighbor" became "thou shall not kill any human." War became murder and demanded extensive justification. In this way the religious instinct, which developed to promote group solidarity against other tribes, metamorphosed into beliefs promoting peace, equality, and justice.

Modern universal religions, such as Islam, Christianity, and Buddhism, reflect at least in part, especially in modern times, these pacifistic doctrines. In their original manifestations, they continued to make essential distinctions between "us" and "them." But insiders were no longer of a single tribe; they were those who belonged to Our Religion. With the development of more secular societies, religious conflict has diminished but not disappeared, while more universal values have grown.

Today, in societies such as the United States, which has practiced religious tolerance for over two hundred years, ecumenical feelings have led to the extension of forbearance to non-Christian religions and to non-Caucasians. Nevertheless tensions between groups linger; people still congregate with their own, and few really welcome those whose beliefs differ greatly from theirs.

In much of the world, even the universal religions still face each other with suspicion and violence. The recent strife in the Balkans can be viewed in a long-term historical context as a continuin struggle between Orthodox Christians, Western Christians, and Muslims. These rivalries go back to the early Middle Ages, the foundation of Constantinople, and to Mohammed.

The last year has seen religious wars in East Timor and other parts of Indonesia, in Kosovo, and in Kashmir. The Canadian Forces College, Department of National Defense, counted 33 contemporary conflicts in 1998 ( links/wars/index.html). Not all of those actually involved violence (China-Taiwan, Cuba-US); but, of the 31 in which people were dying, about half were religious in nature. Another six were ethnic conflicts, which might also have had a religious component. Most of the non-religious or non-ethnic struggles produced low level strife, as in Haiti and Albania. The most bloody were either ethnic or religious quarrels or both.

Religion has been a force for war, violence, and persecution. It has also been a great impetus for good, beauty, and justice. In recent centuries religious feelings have moved towards the more humane; but, in times of distress, anger, or upheaval, the basic tribal loyalties built upon religion, which lie just below the surface, may erupt with disastrous consequences. A major breakdown in a free, prosperous Western civilization may lead to an upsurge of bigotry, tribal conflicts, and killings in the name of God or Gods.


The following example of group altruism’s becoming more common, comes from Sober & Wilson 1998:

Assume there are two groups (tribes) and on average 50 percent of them are religious. If most of the religious people are concentrated in one group, the proportion of religious people will rise. In this example, 80 percent of the religious people to start with are in group two.

X is the average number of offspring

C is the cost of being religious

b is additional offspring another individual will produce.

FR = X — C + [b(np-1)/(n-1)] Fitness of religious person

FS =X + [bnp/(n-1)] Fitness of non-religious person


Group One


Population = n1 =100

Frequency of believers = p = 0.2

Basic fitness = X = 10

Benefit to recipient = b = 5

Cost to believer = 1

Fitness of believer = FR = 10 — 1 = 5(19)/99 = 9.96

Fitness of non-religious = FS = 10 + 5(20)/99 = 11.01

Second Period

n2 = (9.96*20 + 11.01*80) = 1080

p2 = 9.96*20/1080= 0.184


Group Two


n1 = 100

p1 =0.8

FR = 10 —1 +5(79)/99 =12.99

FS = 10 +5(80)99 = 14.04

Second Period

n2 = 1320 = 12.99*80 + 14.04*20

p2 = 12.99*80/1320 = 0.787


Global Population


N1 = 100 + 100 =200

P1 = 100*.02 + 100*0.8 = 0.5

N2 = 1080 + 1320 = 2400

P2 = (1080*0.184 + 1320*0.787)/2400 = 0.516

Within each group the non-religious individuals gain at the expense of the religious; but, since 80 percent of group two are religious and provide benefits to all in that group, the total number of religious people and the percent of religious people in the total population rise. As long as the groups then re-form so that the religious people continue to be concentrated in one group, the proportion in the next period will go up. The best that can be achieved, however, would be that 80 percent of the population would become religious.

Since devout people are easily identified and since lying about one’s religiosity can usually be detected, a group that emphasizes religion can identify and attract such members. In the real world, young women or sometimes young men do leave their tribes to find mates elsewhere. As long as those who are religious are attracted to the more religious tribe, the proportion of religious people in the population can rise up to a maximum of 80 percent. This model, however, requires that the initial population have at least 25 percent religious for the proportion to grow. Moreover, all religious people would have to be concentrated in one tribe.



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