Public prejudice toward atheists is still high, not only in the United States but in most of the countries in the world. Around half of Americans would refuse to vote for an atheist for public office, according to recent polls. Polls also show that the rejection of atheists is mainly due to the public assumption that people who are irreligious are also immoral, since they have no fear of punishment by God. But is God really the source of human morality? Certainly the Judaeo-Christian-Muslim God, invented less than two thousand years ago, is not the source of morality, because humans have probably had a fully developed morality for at least the last 300,000 years. That was well before they first showed signs of being religious, and as I argued in my previous blog post, “The Theology and Science of Free Will,” a religion may reinforce the particular morality of the group that practices it, but morality itself is not religious in origin. Morality actually emerged in the tension between individual humans and the groups that they belonged to, leading to the need of the groups to control the behavior of their members.
In order to understand how this tension developed, we need first to look to the research that has been done on the behavior of our closest relatives, the chimpanzees, both in the wild and in captivity. Chimps and humans had a common ancestor some six or seven million years ago and share over 98% of their DNA, and that is evident in the similarities in their behavior. Chimps, like humans, can be individualistic and selfish and aggressive are potentially violent when they come into conflict with each other. In chimpanzees, a male might want to monopolize access to a female when her swollen, pink bottom shows that she is in estrus or heat and therefore sexually receptive. Consequently, a sort of “pecking order” or dominance hierarchy develops among the chimps, with the alpha male able to fight off or bluff any other male. However, often a female will prefer another male and so sneak off with him into the woods where the alpha male cannot see them. All of the males get to have sex, but because of the females’ as well as the males’ promiscuity, no one knows who fathered particular infants. However, chimp social life is not just about conflict and sex. The chimps share the human pro-social tendencies of sympathy, empathy, reciprocity, and reconciliation. They just don’t have a system of morality.
The human line, classified with us in the genus Homo, split off from the scattering of species intermediate between us and chimpanzees in east Africa nearly two million years ago. Homo Erectus, as the name implies, stood erect, with long, striding legs and shoulders adapted for throwing things. They got much of their protein as scavengers: When they learned that carnivores had killed a large animal, perhaps because they spotted the vultures circling above it, they raced across the savannah and converged as a group on the scene, screaming and yelling and throwing rocks until the pack of carnivores fled. Then these proto-humans used their carefully crafted “hand-axes” (stone discs with a cutting edge all around) to carve up the meat so they could carry it to their camp. They were safe there on the ground, even at night, because they could build a fire to keep predators at bay in the dark. They had not, apparently, discovered the advantages of cooking the meat in the fire, or at least they had not figured out how to do it properly.
Robin Dunbar, in his book Human Evolution: Our Brains and Our Behavior, has estimated the “mentalizing” abilities of our various pre-human ancestors on the basis of the sizes of their brain-cases. He defines intelligence in terms of “levels of intentionality” or how many individuals’ intentions can be kept in mind at the same time. All mammals have at least first-order intentionality: They form their own intentions and carry them into action. (I called that free will in my first blog.). Elephants, dolphins and apes, including chimps, have second-order intentionality: They not only form intentions that direct their own actions, they also recognize that other members of their group do so. Dunbar estimates that modern humans have fifth-order intentionality: We can form our own intentions and follow the intentions, attitudes, and points of view of four other people, all at the same time. Erectus and other species in the human line had at least third-order intentionality: They they knew that they had intentions, attitudes, and emotions and that others of their kind did, as well, and they could also turn around and look at themselves from the point of view of the other members of their own groups.
Dunbar focuses on the need of groups such as the Erectus scavenger-bands to maintain social bonds or a feeling unity among the members so they would be able to stay together and cooperate. He suggests that they might have used laughter (perhaps in response to physical comedy by the “class clowns” among them) to create warm feelings in the group. He does not recognize that such feelings were not enough to overcome the conflicts that boiled up among the selfish, aggressive individualists that made up the band. Some kind of social control or morality would have to have been imposed on them by the group. But laughter could have helped to do that job as well. Erectus were capable of third-order intentionality but were not capable of articulate speech. Instead, they would have had a variety of verbal calls and/or gestures that could have been used to express their emotions. I therefore propose the hypothesis that Erectus groups could have used shame as means of social control. Their gestures and calls could have shown social disapproval, but laughter is the most powerful shaming mechanism. It erupts spontaneously when someone does something socially inappropriate. The shamed individual would have seen herself from the point of view of the group and felt negatively about herself to the same degree that her group did. The blushing response to shaming must have evolved prior to language, at the Erectus stage, since it is not necessary when people can apologize for what they do. The individuals who blushed would be seen to be accepting the group’s point of view and would have therefore been forgiven for their unacceptable behavior. Those who did not blush and did not correct their behavior to avoid shaming might have been thrown out of the group and would probably not have survived alone on the savannah, much less have been able to reproduce the genes that did not code for blushing.
Homo Heidelbergensis evolved out of Homo Erectus in Africa about 600,000 years ago. They were capable of articulate speech as well as of third-order intentionality and therefore the members of its bands were capable of coming to agreements among themselves that stated social rules and standards of behavior for themselves. The three levels of intentionality were in play at each stage of negotiations: Each individual formed the idea of coming to an agreement that represented the point of view of the group, each intended to do so, and each knew that the others intended to do so as well. Next, each acknowledged that agreement as stating the expectations of the group when it was reached, pledged to abide by it, and knew that the others did the same. And finally, each could compare the standards set in that agreement to his own behavior and to that of the others. But a rational contract of this sort is not self-enforcing. A coldly rational individual would not take the risk and make the effort to enforce the contract on another individual on behalf of the group. I therefore propose the hypothesis that to strengthen enforcement of group moral standards, the Heidelbergs evolved the uniquely human emotion of moral outrage at violators of the group’s moral rules or norms; I also propose the hypothesis that moral outrage directed against the self for violating those norms is the source of the feeling of guilt. Heidelberg groups whose members had these emotions of outrage and guilt would have been much more effective at enforcing their own morality on each other and the members also would be more likely to enforce the rules on themselves. Therefore those groups would be more cohesive and cooperative and successful in ensuring their own survival and reproduction. Individuals who had not evolved these emotions and therefore did not enforce the group’s moral standards on themselves and on the others would be likely to be thrown out of the group and die.
The major kind of social agreement that the Heidelbergs developed was marriage, a huge innovation in human morality. Richard Wrangham in his book, Catching Fire, shows that it was the discovery and spread of cooking led to the establishment of the institution of marriage. Cooking greatly increases the digestibility and nutritional value of food, especially of meat and root vegetables such as potatoes. It therefore made possible a rapid evolutionary increase in the size of the brain. The brain is the most voracious organ in the body, using much more than its share of the energy obtained from metabolizing food. Enough energy for larger brains was available only when eating cooked food. Cooking food also enabled a mother to provide sufficient easily consumed nutrition for then needs of children with rapidly developing brains and thereby increased their chances of survival. But she could not do it alone. Unlike the families of all but one species of ape, human families typically do not just include a mother and her children; they also include an adult male, ideally the father of the children. That is because, until the invention modern appliances, at least one member of the family had to spend hours during the day maintaining the cooking fire and making sure that the food was cooked properly. And at the same time that cooking developed, humans were becoming more proficient hunters. Hunting itself is time consuming, and one person cannot spend enough time hunting and enough time maintaining the fire during the day and gathering and cooking vegetables to survive. A partner was needed to compensate for this time constraint. Human mothers would gather wild vegetable foods of various sorts and cook that food at each family’s cooking fire in the group’s campground while the men in their group were off hunting much of the day. But when one of those men returned, he could raid the campsite of any woman to steal the food she had been cooking.
Wrangham argues that the cultural solution to this problem was marriage, in which the husband agreed to became the protector of his wife, who in turn agreed to cook for him and their children. The husband protected his wife not by standing guard at the fire, but by coming to a moral agreement with the other men in the group that they would respect each man’s right to the food prepared by his own wife as well as his exclusive sexual access to her. Second, the men also agreed that they would share the meat from any large animal killed by any member of the group, so that each man’s wife would have meat to cook along with the vegetables that she had gathered. Third, they agreed that in decision making affecting the group, no one would be allowed to act as boss. Each married man would have an equal say in the discussions leading to any decision. This morality of equality, sharing, and marriage is universal among human hunting-gathering cultures because no other social pattern is compatible with that way of life. It was not inevitable that such a complex cultural arrangement would be worked out, and many human hunting and gathering groups probably died out because they failed to achieve it. The first to achieve it were the Heidelbergs. Numerous cooking fires only appear in the archaeological record in their time, 400,000 years ago, followed after another 100,000 years by a dramatic evolutionary increase in their skull and brain size, made possible by their improved nutrition. They later evolved into modern humans in Africa and into Neanderthals in Europe.
Marriage, as adaptive as it was in the context of the hunting-gathering lifestyle, was not easy for these human ancestors to maintain, with their chimp-like desires and emotions. But they evolved further biologically to enable them to conform to the moral standards they had set for themselves. Most obviously, women evolved to stop showing the pink swellings of their genitals that female chimpanzees showed during estrus. The same evolutionary change made women sexually receptive whether they were in their short period of fertility or not, so wives would be willing and able to entertain their husbands almost any time of the month, making it unnecessary for their husbands to stray into the arms of other women. A less obvious change was the evolution of a new function for an old hormone, oxytocin. In all mammals, its release into the bloodstream and the brain is stimulated in a pregnant female by the vaginal birth of her offspring, and the hormone primes her to become emotionally attached to the infant and to want to care for it. Physical contact between the mother and infant in the course of that care stimulates further releases of the hormone in her and in the baby. Not only that; it is also released during vaginal sexual intercourse, in human males as well as females. And it reaches sustained high levels in romantically involved couples. It makes them feel happy and relaxed as a result of having physical contact with each other or even of just thinking about their partner. So long as that effect lasts, the couple are likely to have eyes only for each other and stay loyal to their marriage. Those who evolved that reaction to oxytocin were more likely to stay together and raise their children successfully to become healthy adults who would reproduce their parents’ new genes, so the pattern spread to the whole population of Heidelbergs and their descendants, ourselves.
My conclusion is an extension of the argument of my first blog, "The Theology and Science of Free Will." Humans have exercised free will, not just over their own actions, but also over their own evolution. Most of the biological evolution of the human line for the last two million years has resulted from the intentional innovations that the proto-humans made in their ways of feeding themselves, their technology, their social organization, their culture—and their morality. These evolutionary changes have enabled them to adapt more easily and willingly to the new socio-cultural environment that they have created for themselves, from the blushing response to shaming evolved by Erectus to signal their acceptance of the group’s point of view to the romantic feelings evolved by Heidelbergs to hold their marriages together.