Science of Good and Evil

by Michael Shermer

  The Mahabharata, c. 150 B.C.E.: “This is the sum of all true righteousness: deal with others as thou wouldst thyself be dealt by. Do nothing to thy neighbor which thou wouldst not have him do to thee hereafter.”

  Matt. 7:12, c. first century C.E.: “All things whatsoever ye would that men should do to you, do ye even so to them: for this is the law and the prophets.”

  Luke 6:31, c. first century C.E.: “As ye would that men should do to you, do ye also to them likewise”

  Epictetus, Encheiridion, c. 100: “What thou avoidest suffering thyself seek not to impose on others.”

  The Didache, or Teaching of the Twelve Apostles, c. 135: “All things whatsoever that thou wouldst not wish to be done to thee, do thou also not to another.”

  John Wycliffe, translation of Luke 7:31, 1389: “As ye will that men do to you, and do ye to them in like manner.”

  David Fergusson, Scottish Proverbs, 1641: “Do as ye wald be done to.”

  Thomas Hobbes, Leviathan, 1651: “Whatsoever you require that others should do to you, that do ye to them.”

  The Book of Common Prayer (catechism), 1662: “My duty towards my neighbor is to love him as myself, and to do to all men as I would they should do unto me.”

  Henry More, Enchiridion ethicum, 4, 1667: “The evil which you do not wish done to you, you ought to refrain from doing to another, so far as may be done without injury to some third person.”

  Baruch Spinoza, Ethica, 4, 1677: “Desire nothing for yourself which you do not desire for others.”

  John Wise, A Vindication of the Government of New England Churches, 1717: “If a man any ways doubt whether what he is going to do to another man be agreeable to the law of nature, then let him suppose himself to be in that other man’s room.”

  John Stuart Mill, Utilitarianism, 1863: “To do, as one would be done by, and to love one’s neighbor as one’s self, constitute the ideal perfection of utilitarian morality.”

  Henry Sidgwick, The Methods of Ethics, 1874: “Reason shows me that if my happiness is desirable and a good, the equal happiness of any other person must be equally desirable.”

  Peter Kropotkin, La Morale Anarchiste, 1891: “Do unto others as you would have others do unto you in like case.”

  Hillel Ha-Babli, in the thirty-first book of The Sabbath in 30 B.C.E., raised the Golden Rule to the ultimate moral principle: “Whatsoever thou wouldst that men should not do to thee, do not do that to them. This is the whole Law. The rest is only explanation.” That explanation, however, forms the basis of the evolutionary origins of morality, beginning with the evolution of the premoral sentiments.

  The Evolution of Premorality

  Our moral sentiments—the moral emotions contained within our mental armory—evolved out of premoral feelings of our hominid, primate, and mammalian ancestors, the remnants of which can be found in modern apes, monkeys, and other big-brained mammals. I consider these sentiments to be premoral because morality involves right and wrong thoughts and behaviors in the context of a social group. To date, it does not appear that nonhuman animals can consciously assess the rightness or wrongness of a thought, behavior, or choice in themselves or fellow members of their species. Thus, I hold that morality is the exclusive domain of Homo sapiens.

  Of course, we are animals and so it is not surprising to discover premoral sentiments in other animals. And, equally unsurprising, the more like us a species is the more moral-like are their premoral sentiments, such as those observed in the great apes (e.g., chimpanzees, bonobos, and gorillas), monkeys (e.g., rhesus, baboons, and macaques), and other big-brained mammals (e.g., whales and dolphins). As we travel across the phylogenetic (evolutionary) scale away from humans we see that mammals exhibit more premoral behaviors than nonmammals (e.g., reptiles). In fact, when we examine the evolutionary sequence in detail we see that there is no distinct place to draw the line between moral and nonmoral, a problem created by the restrictive nature of binary logic. In binary logic one sees the world as black or white, up or down, in or out. In fuzzy logic one sees the world in shades of gray, between up and down, in and out. Instead of dividing the world into binary digits of 0 or 1, we can nuance it with shades in between (.1, .2, .3 … .9). Instead of simply saying that humans are moral and animals are not moral (1 and 0), we could describe humans as .9 or .8 moral, the great apes as .7 or .6 moral, monkeys as .5 or .4 moral, whales and dolphins as .3 or .2 moral, and so forth. This is why a scientific analysis of morality can be more fruitful than a philosophical one. An evolutionary perspective grants other animals degrees of morality (or premorality) that allows us to discover how we developed our moral sentiments; it also grants them greater dignity and status than does a nonevolutionary perspective.

  Let us begin with household pets such as dogs and cats, since they are arguably the animals of which we are most intimately knowledgeable. Surely few outside of extreme animal rights’ activists would claim that dogs and cats are moral animals, yet anyone who has had one for a pet for very long recognizes that they quickly learn the difference between right and wrong, and that dogs, especially, feel some sense of shame or guilt when being scolded for bad behavior and openly express joy and pride when being praised for good behavior. That sense of shame and guilt, or joy and pride, is what I mean by moral sentiments. But it appears that dogs and cats are not self-aware and self-conscious of their and other dogs’ and cats’ good and bad behavior—at least to an extent that would allow them to assess a moral judgment upon another member of their species (even if they cannot articulate it due to lack of language and speech apparatus). It might be more appropriate to call these premoral sentiments. (Some would debate this point, noting that wolf parents appear to teach their offspring the difference between right and wrong behavior, at least in terms of survival.) 1

  The difference between dogs and cats in the expression of such premoral sentiments reveals the importance of another component in morality—the social group. Cats are notoriously individualistic and independent, not typically herd or hierarchical social animals, especially when compared to dogs, who in the wild travel in packs with pecking orders (particularly noted in wolves, from which all dogs evolved) and in domestic situations establish social bonds with members of the household. (It is well known among dog trainers that the first rule of obedience is to establish yourself as the alpha member of the home, thereby relegating your dog to a lower rung in the pecking order.)

  Examples of premoral sentiments among animals abound. It has been well documented that vampire bats, for example, exhibit food-sharing behavior and the principle of reciprocity. They go out at night in hordes seeking large sleeping mammals from which they can suck blood. Not all are successful, yet all need to eat regularly because of their excessively high metabolism. On average, older experienced bats fail one night in ten, younger inexperienced bats fail one night in three. Their solution: successful individuals regurgitate blood and share it with their less fortunate comrades, fully expecting reciprocity the next time they come home sans bacon. Gerald Wilkinson, in his extensive study of cooperation in vampire bats, has even identified a “buddy system” among bats, in which two individuals share and reciprocate from night to night, depending on their successes or failures. He found that the degree of affiliation between two bats—that is, the number of times they were observed together—predicted how often they would share food. Since bats live for upwards of eighteen years among the same community, they know who the cooperators are and who the defectors are.2 Of course, the bats are not aware they are being cooperative in any conscious goodwill sense. All animals, including human animals, are just trying to survive, and it turns out that cooperation is a good strategy. This is especially apparent in the primates.

  Psychologist and primatologist Frans de Waal has documented hundreds of examples of premoral sentiments among apes and monkeys. At the Yerkes Field Station where he and his colleagues observe their primate charges from on high, de Waal reveals the high level of conflict among these social spec
ies, as well as how those conflicts are resolved: “These records show that once the dust has settled after a fight, combatants are often approached by uninvolved bystanders. Typically the bystanders hug and touch them, pat them on the back, or groom them for a while. These contacts are aimed at precisely those individuals expected to be most upset by the preceding event.” This is most apparent in the chimpanzees, our closest evolutionary relatives: “When upset, chimpanzees pout, whimper, yelp, beg with outstretched hand, or impatiently shake both hands so that the other will hurry and provide the calming contact so urgently needed. If all else fails, chimpanzees resort to their ultimate weapon, the temper tantrum. They lose control, roll around screaming pathetically, hitting their own head or beating the ground with their fists, regularly checking the effects on the other.”3

  Aristotle described humans as political animals. De Waal has discovered that chimpanzees are political animals as well (figure 1). When he shifted his research from macaques to chimps, he writes, “I was totally unprepared for the finesse with which these apes con each other. I saw them wipe undesirable expressions off their face, hide compromising body parts behind their hands, and act totally blind and deaf when another tested their nerves with a noisy intimidation display.”4 Politics—human and chimp—depends on reciprocity, and this too has been cleverly studied by de Waal in experiments whereby in order to obtain a heavy bucket of food two chimps must work together to pull it up with ropes. Although both are needed to haul the bucket up to the cage (where they are separated by a barrier), only one gets the food. De Waal discovered that if the recipient of the food did not share it with his companion, the companion refused to cooperate in the rope pulling in subsequent trials. In the long run, however, “cooperative behavior between two primates leads to greater food sharing after the task in which the cooperation occurred.”5 Quid pro quo.

  Figure 1. Food Sharing in Chimpanzees

  As documented by psychologist Frans de Waal at the Yerkes Field Station, four chimpanzee adults and one infant (seen in the food pile) participate in a vital social exchange process of food sharing that encourages cooperation and reciprocal altruism. In this group, the exchange process is controlled by the possessor female in the upper right corner. The female in the lower left reaches for food; whether it will be granted or not depends on her relationship to the possessor female. (Photograph by Frans de Waal)

  Other scientists have documented premoral sentiments in other higher mammals. Dolphins have been seen to push sick or wounded members of a pod to the surface so that they may catch their breath. Whale fishermen know—and capitalize on the fact—that whales will put themselves in harm’s way by coming to the defense of a wounded member of their group, circling them and striking the water with their flukes (thereby alerting the hunters to their whereabouts). One theory for why whales beach themselves in what often appears to be mass suicide is that, in fact, one member is disoriented and gets beached, and the others follow trying to help. In 1976 a pod of thirty false killer whales heaved themselves up on a Florida beach where they remained for three days; after one of their members died, the rest returned to the sea (able to do so because of a fortunate timing of the tides).6 Cynthia Moss recorded the responses of a community of elephants to one of their members being shot by a poacher. As the struck elephant’s knees buckled and she began to go down, her elephant comrades struggled to keep her upright. “They worked their tusks under her back and under her head. At one point they succeeded in lifting her into a sitting position but her body flopped back down. Her family tried everything to rouse her, kicking and tusking her, and Tallulah even went off and collected a trunkful of grass and tried to stuff it into her mouth.” After she died, her friends and family members covered the corpse in dirt and branches.7

  Hundreds of such examples exist in the scientific literature, and thousands more in popular literature.8 The following characteristics appear to be shared by humans and other mammals, including and especially the apes, monkeys, dolphins, and whales: attachment and bonding, cooperation and mutual aid, sympathy and empathy, direct and indirect reciprocity, altruism and reciprocal altruism, conflict resolution and peacemaking, deception and deception detection, community concern and caring about what others think about you, and awareness of and response to the social rules of the group. Species differ in the degree to which they express these sentiments, and with our exceptionally large brains (especially the well-developed and highly convoluted cortex) we clearly express most of them in greater degrees than other species. Nevertheless, the fact that such premoral sentiments exist in our nearest evolutionary cousins may be a strong indication of their evolutionary origins. Still, something profound happened in the last 100,000 years that made us—and no other species—moral animals to a degree unprecedented in nature.

  The Evolution of Morality

  For the first 90,000 years of our existence as a species—that is, as anatomically modern humans distinct from other hominid species such as the Neanderthals—humans lived in small bands of tens to hundreds of individuals. In the last 10,000 years—only 10 percent of Homo sapiens’ existence—some bands evolved into tribes of thousands of individuals, some tribes developed into chiefdoms of tens of thousands of individuals, some chiefdoms coalesced into states of hundreds of thousands of individuals, and a handful of states conjoined together into empires of millions of individuals. Within a rough order of magnitude comparison, the evolution of our species proceeded as depicted in table 2. (Recent fossil finds in Ethiopia by paleoanthropologist Tim White and his team indicate that anatomically modern humans may date to 160,000 years. The DNA evidence also supports this claim, although such figures come equipped with some error, meaning that the rough estimates presented here are legitimate.)9

  TABLE 2

  The Social Evolution of Humans Over the Past 100,000 Years

  100,000–10,000 years Bands 10s–100s of individuals

  10,000–5,000 years Tribes 100s–1,000s of individuals

  5,000–3,000 years Chiefdoms 1,000s–10,000s of individuals

  3,000–1,000 years States 10,000s–100,000s of individuals

  1,000–present Empires 100,000s–1,000,000s of individuals

  Somewhere along the way, moral sentiments evolved out of the premoral sentiments of our primate and hominid ancestors and moral codes were created. Generally speaking, moral sentiments as expressed in thoughts and behaviors evolved during those first 90,000 years when we lived in bands. In the last 10,000 years, these moral thoughts and behaviors were codified into moral rules and principles by religions that arose as a direct function of the shift from tribes to chiefdoms to states.10 How and why did this happen?

  The human story begins roughly six to seven million years ago when a hominid primate branched off from the common ancestor shared by our primate contemporary, the chimpanzees. Two to three million years ago hominids in Olduvai Gorge in east Africa began chipping stones into tools and altering their environment. Around one million years ago Homo erectus added controlled fire to hominid technology, and between half a million and 100,000 years ago other hominids, such as Homo neanderthalensis and Homo heidelbergensis, lived in caves, had relatively elaborate tool kits, and developed throwing spears with finely crafted spear points. The evidence is now overwhelming that many hominid species lived simultaneously, and at present we can only speculate what speciation pressures these changing technologies put on natural selection.11

  Sometime around 35,000 years ago one hominid species improved its tool kit dramatically, making it noticeably (in the fossil record) more complex and varied. Suddenly clothing covered their bodies, art adorned their caves, bones and wood formed the structure of their living abodes, and, perhaps most significantly, language produced sophisticated symbolic communication. They even buried their dead in prepared grave sites with burial ceremonies (figure 2). By 13,000 years ago our species had spread to nearly every region of the globe and all people everywhere lived in a condition of hunting, fishing, and gathering
(HFG). Most were nomadic, staying in one place for no longer than a few weeks at a time. Small bands grew into larger tribes, and with this shift, possessions became valuable, rules of conduct grew more complex, and population numbers climbed steadily upward. When population pressures in numerous places around the globe grew too intense for the HFG lifestyle to support, an agricultural revolution sprouted.12 New food-production technologies allowed populations to increase dramatically. With those increased populations came new social technologies for governance and conflict resolution. The creation of tribes from bands began around 13,000 years ago. Archaeological evidence indicates that the coalition of tribes into chiefdoms occurred in the Fertile Crescent of western Asia around 7,500 years ago. Within 2,000 years—roughly 5,500 years ago—chiefdoms began to merge into states in the same general area.

  Figure 2. The Evolutionary Origins of Morality 100,000 Years Ago

  The moral sentiments evolved roughly 100,000 years ago among bands of hunter-gatherers who learned to cooperate with each other and compete with other hominid groups. Depicted here is the burial of a child at Qafzeh Cave in Israel, the oldest-known decorated grave site in the world, where paleoanthropologists discovered the skeleton of a child grasping the skull of a fallow deer. (Courtesy of W. W. Norton)

  The concomitant leap in food production and population that accompanied the shift to chiefdoms and states allowed for a division of labor to develop in both economic and social spheres. Full-time artisans, craftsmen, and scribes worked within a social structure organized and run by full-time politicians, bureaucrats, and, to pay for it all, tax collectors. Organized religion came of age—along with these other social institutions—to fill many roles, not the least of which was the justification of power for the ruling elite. The “divine right of kings” is not the invention of early-modern European monarchs. In fact, every chiefdom and state society known to archaeologists from around the world, including those in the Middle East, Near East, Far East, North and South America, and the Polynesian Pacific islands, justified political power through divine sanction, in which the chief, pharaoh, king, queen, monarch, emperor, sovereign, or ruler of whatever title claimed a relationship to God or the gods, who allegedly anointed them with the power to act on behalf of the divinity. In a type of reciprocal exchange program, the masses would pay for this divine connection through taxes, loyalty, and service to the chiefdom or state (for example, through military inscription). As states evolved into bona fide civilizations and the centuries witnessed small cults evolve into world religions, behavior commitments evolved into standardized rituals, accompanied by the appropriate architectural displays of both political and religious power.13 Organized religion as we know it was born.