Preface. This is a book of review of The Social Conquest of Earth, in which E. O. Wilson answers these questions. Although tribes have invented thousands of creation myths since paleolithic times, Wilson finally has written a book explaining our true creation myth.
We are shaped by both individual and group selection, which forever traps us between the conflict of the poorer and better angels of our nature. Individual selection is responsible for much of what we call sin, while group selection is responsible for the greater part of virtue.
It is fortunate that we are intrinsically imperfectible, because in a constantly changing world, we need the flexibility that only imperfection provides.
Below are some of my kindle notes. This is one of the most profound books you could ever read, and I leave so much out that I hope you’ll simply have to buy the book, and perhaps pass it on to increase the Enlightenment and diminish superstition.
Alice Friedemann www.energyskeptic.com author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer, Barriers to Making Algal Biofuels, and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts: Collapse Chronicles, Derrick Jensen, Practical Prepping, KunstlerCast 253, KunstlerCast278, Peak Prosperity , XX2 report
Wilson, E. O. 2012. The Social Conquest of Earth. Liveright.
There is no grail more elusive or precious in the life of the mind than the key to understanding the human condition. It has always been the custom of those who seek it to explore the labyrinth of myth: for religion, the myths of creation and the dreams of prophets; for philosophers, the insights of introspection and reasoning based upon them; for the creative arts, statements based upon a play of the senses.
Humanity today is like a waking dreamer, caught between the fantasies of sleep and the chaos of the real world.
We have created a Star Wars civilization, with Stone Age emotions, medieval institutions, and godlike technology. We thrash about. We are terribly confused by the mere fact of our existence, and a danger to ourselves and to the rest of life. Religion will never solve this great riddle.
Since Paleolithic times each tribe—of which there have been countless thousands—invented its own creation myth. During this long dreamtime of our ancestors, supernatural beings spoke to shamans and prophets. They identified themselves to the mortals variously as God, a tribe of Gods, a divine family, the Great Spirit, the Sun, ghosts of the forebears, supreme serpents, hybrids of sundry animals, chimeras of men and beasts, omnipotent sky spiders—anything, everything that could be conjured by the dreams, hallucinogens, and fertile imaginations of the spiritual leaders.
They were shaped in part by the environments of those who invented them. In Polynesia, gods pried the sky apart from the ground and sea, and the creation of life and humanity followed. In the desert-dwelling patriarchies of Judaism, Christianity, and Islam, prophets conceived, not surprisingly, a divine, all-powerful patriarch who speaks to his people through sacred scripture.
The creation stories gave the members of each tribe an explanation for their existence. It made them feel loved and protected above all other tribes. In return, their gods demanded absolute belief and obedience. And rightly so. The creation myth was the essential bond that held the tribe together. It provided its believers with a unique identity, commanded their fidelity, strengthened order, vouchsafed law, encouraged valor and sacrifice, and offered meaning to the cycles of life and death. No tribe could long survive without the meaning of its existence defined by a creation story. The option was to weaken, dissolve, and die. In the early history of each tribe, the myth therefore had to be set in stone.
The discovery of the origin and meaning of humanity might explain the origin and meaning of myths, hence the core of organized religion. Can these two worldviews ever be reconciled? The answer, to put the matter honestly and simply, is no. They cannot be reconciled. Their opposition defines the difference between science and religion, between trust in empiricism and belief in the supernatural.
Thinking about thinking is the core process of the creative arts, but it tells us very little about how we think the way we do, and nothing of why the creative arts originated in the first place. Consciousness, having evolved over millions of years of life-and-death struggle, and moreover because of that struggle, was not designed for self-examination. It was designed for survival and reproduction. Conscious thought is driven by emotion; to the purpose of survival and reproduction, it is ultimately and wholly committed. The intricate distortions of the mind may be transmitted by the creative arts in fine detail, but they are constructed as though human nature never had an evolutionary history. Their powerful metaphors have brought us no closer to solving the riddle than did the dramas and literature of ancient Greece.
What science promises, and has already supplied in part, is the following. There is a real creation story of humanity, and one only, and it is not a myth. It answers the questions of where we came from and what we are.
The first question is why advanced social life exists at all, and has occurred so rarely in the history of life. The second is the identity of the driving forces that brought it into existence.
These problems can be solved by bringing together information from multiple disciplines, ranging from molecular genetics, neuroscience, and evolutionary biology to archaeology, ecology, social psychology, and history. To test any such theory of complex process, it is useful to bring into the light those other social conquerors of Earth, the highly social ants, bees, wasps, and termites, and I will do so. They are needed for perspective in developing the theory of social evolution. I realize I can be easily misinterpreted by putting insects next to people. Apes are bad enough, you might say, but insects?
Human beings create cultures by means of malleable languages. We invent symbols that are intended to be understood among ourselves, and we thereby generate networks of communication many orders of magnitude greater than that of any animal. We have conquered the biosphere and laid waste to it like no other species in the history of life.
We are an evolutionary chimera, living on intelligence steered by the demands of animal instinct. This is the reason we are mindlessly dismantling the biosphere and, with it, our own prospects for permanent existence.
A vast array of plant and animal species formed intimate symbioses with the social insects, accepting them as partners. A large percentage came to depend on them entirely for survival, variously as prey, symbionts, scavengers, pollinators, or turners of the soil. Overall, the pace of evolution of ants and termites was slow enough to be balanced by counter-evolution in the rest of life. As a result, these insects were not able to tear down the rest of the terrestrial biosphere by force of numbers, but became vital elements of it. The ecosystems they dominate today are not only sustainable but dependent on them.
In sharp contrast, human beings of the single species Homo sapiens emerged in the last several hundred thousand years and spread around the world only during the last sixty thousand years. There was not time for us to coevolve with the rest of the biosphere. Other species were not prepared for the onslaught. This shortfall soon had dire consequences for the rest of life.
Wherever humans saturated wildlands, biodiversity was returned to the paucity of its earliest period half a billion years previously. The rest of the living world could not coevolve fast enough to accommodate the onslaught of a spectacular conqueror that seemed to come from nowhere, and it began to crumble from the pressure.
Even by strictly technical definition as applied to animals, Homo sapiens is what biologists call “eusocial,” meaning group members containing multiple generations and prone to perform altruistic acts as part of their division of labor.
The necessity for fine-graded evaluation by alliance members meant that the pre-human ancestors had to achieve eusociality in a radically different way from the instinct-driven insects. The pathway to eusociality was charted by a contest between selection based on the relative success of individuals within groups versus relative success among groups. The strategies of this game were written as a complicated mix of closely calibrated altruism, cooperation, competition, domination, reciprocity, defection, and deceit. To play the game the human way, it was necessary for the evolving populations to acquire an ever higher degree of intelligence. They had to feel empathy for others, to measure the emotions of friend and enemy alike, to judge the intentions of all of them, and to plan a strategy for personal social interactions. As a result, the human brain became simultaneously highly intelligent and intensely social. It had to build mental scenarios of personal relationships rapidly, both short-term and long-term. Its memories had to travel far into the past to summon old scenarios and far into the future to imagine the consequences of every relationship.
Thus was born the human condition, selfish at one time, selfless at another, the two impulses often conflicted. How did Homo sapiens reach this unique place in its journey through the great maze of evolution? The answer is that our destiny was foreordained by two biological properties of our distant ancestors: large size and limited mobility.
While eusocial species can dominate the insect world in terms of numbers of individuals, they had to rely on small brains and pure instinct for their conquest. Furthermore, and fundamentally, they were too small to ignite and control fire.
Mammals, especially carnivores, have much larger territories to defend when they settle down to build a nest. Wherever they travel, they are likely to encounter rivals. Females cannot store sperm in their bodies. They must find a male and mate for each parturition. Should the opportunities and pressures of the environment make social grouping profitable, it must be done with personal bonds and alliances based on intelligence and memory. To summarize to this point on the two social conquerors of Earth, the physiology and life cycle in the ancestors of the social insects and those of humans differed fundamentally in the evolutionary pathways followed to the formation of advanced societies.
In every game of evolutionary chance, played from one generation to the next, a very large number of individuals must live and die. The number, however, is not countless. A rough estimate can be made of it, providing at least a plausible order-of-magnitude guess. For the entire course of evolution leading from our primitive mammalian forebears of a hundred million years ago to the single lineage that threaded its way to become the first Homo sapiens, the total number of individuals it required might have been one hundred billion.
The first preadaptation was the aforementioned large size and relative immobility that predetermined the trajectory of mammalian evolution, as distinct from that of the social insects. The second preadaptation in the human-bound timeline was the specialization of the early primates, 70 to 80 million years ago, to life in the trees. The most important feature evolved in this change was hands and feet built for grasping. Moreover, their shape and muscles were better suited for swinging from branches, rather than merely grasping them for support. Their efficiency was increased by the simultaneous appearance of opposable thumbs and great toes. It was increased further by modification of the finger and toe tips into flat nails, as opposed to sharp down curving claws of the kind possessed by most other kinds of arboreal mammals. In addition, the palms and soles were covered by cutaneous ridges that aided in grasping; and they were supplied with pressure receptors that enhanced the sense of touch. Thus equipped, the early primate could use its hand to pick and tease apart pieces of fruit while pulling out individual seeds. The fingernail edges could both cut and scrape objects grasped by the hands. Such an animal, using its hind legs for locomotion, would be able to carry food for considerable distances.
The early prehuman primates evolved a larger brain. For the same reason, they came to depend more on vision and less on smell than did most other mammals. They acquired large eyes with color vision, which were placed forward on the head to give binocular vision and a better sense of depth. When walking, the pre-human primate did not move its hind legs well apart in parallel; instead, it alternated its legs almost in a single line, one foot placed in front of the other. The offspring, moreover, were fewer in number and required more time to develop.
When one line of these strange arboreal creatures evolved to live on the ground, as it happened in Africa, the next preadaptation was taken—one more fortunate turn in the evolutionary maze. Bipedalism was adopted, freeing the hands for other purposes.
The pre-humans, now distinguishable as a group of species called the australopithecines, took the trend to bipedal walking much farther. Their body as a whole was accordingly refashioned. The legs were lengthened and straightened, and the feet were elongated to create a rocking movement during locomotion. The pelvis was reformed into a shallow bowl to support the viscera, which now pressed toward the legs instead of being slung, ape-like, beneath the horizontal body.
The bipedal revolution was very likely responsible for the overall success of the australopithecine pre-humans—at least as measured by the diversity they achieved in body form, jaw musculature, and dentition.
Walking with arms swinging at the side in the new, australopith manner conferred speed at minimal energy cost, even as it inflicted back and knee problems in addition to the greater risk imposed by balancing the newly heavy globular head on a delicate vertical neck. For primates whose bodies had been originally crafted for life in the trees, the bipeds could run swiftly. But they could not match the four-legged animals they hunted as prey.
If the early humans, however, could not outsprint such animal Olympians, they could at least outlast them in a marathon. At some point, humans became long-distance runners. They needed only to commence a chase and track the prey for mile after mile until it was exhausted and could be overtaken. The pre-human body, thrusting itself off the ball of the foot with each step and holding a steady pace, evolved a high aerobic capacity. In time the body also shed all of its hair, except on the head and pubis and in the pheromone-producing armpits. It added sweat glands everywhere, allowing increased rapid cooling of the naked body surface.
Meanwhile, the forelimbs of the pre-human ancestors were redesigned for flexibility in the manipulation of objects. The arm, especially that of males, became efficient at throwing objects, including stones, and later spears as well, and so for the first time the pre-humans could kill at a distance. The advantage this ability gave them during conflict with other, less well-equipped groups must have been enormous.
The next step taken on the road to eusociality was the control of fire. The roving pre-humans could not have failed to discover the importance of wildfires as a source of food. Moreover, they found some of the felled animals already cooked, with flesh easy to tear off and eat.
The use of fire was on the other hand forever denied to insects and other terrestrial invertebrates. They were physically too small to ignite tinder or carry a flaming object without becoming part of the fuel.
It was, of course, also denied aquatic animals
A Homo sapiens level of intelligence can arise only on land, whether here on Earth or on any other conceivable planet.
Why is a protected nest so important to eusociality?
The next step, and the decisive one for the origin of human eusociality, was the gathering of small groups at campsites. There is an a priori reason for believing campsites were the crucial adaptation on the path to eusociality: campsites are in essence nests made by human beings. All animal species that have achieved eusociality, without exception, at first built nests that they defended from enemies. They, as did their known antecedents, raised young in the nest, foraged away from it for food, and brought the bounty back to share with others.
Why is a protected nest so important? Because members of the group are forced to come together there. Required to explore and forage away from the nest, they must also return. Chimpanzees and bonobos occupy and defend territories, but wander through them while searching for food. Chimps and bonobos alternatively break into subgroups and re-aggregate. They advertise the discovery of fruit-laden trees by calling back and forth but do not share the fruit they pick. They occasionally hunt in small packs. Successful members of the pack share the meat among their fellow hunters, but charity mostly comes to an end there. Of greatest importance, the apes have no campfire around which to gather.
Carnivores at campsites are forced to behave in ways not needed by wanderers in the field. They must divide labor: some forage and hunt, others guard the campsite and young. They must share food, both vegetable and animal, in ways that are acceptable to all. Otherwise, the bonds that bind them will weaken. Further, the group members inevitably compete with one another, for status of a larger share of food, for access to an available mate, and for a comfortable sleeping place. All of these pressures confer an advantage on those able to read the intention of others, grow in the ability to gain trust and alliance, and manage rivals. Social intelligence was therefore always at a high premium. A sharp sense of empathy can make a huge difference, and with it an ability to manipulate, to gain cooperation, and to deceive. To put the matter as simply as possible, it pays to be socially smart. Without doubt, a group of smart pre-humans could defeat and displace a group of dumb, ignorant pre-humans, as true then as it is today for armies, corporations, and football teams.
Altricial bird species—those that rear helpless young—have a similar preadaptation. In a few species young adults remain with the parents for a while to help care for their siblings. But no bird species has gone on to evolve full-blown eusocial societies. Possessing only a beak and claws, they have never been equipped to handle tools with any degree of sophistication, or fire at all. Wolves and African wild dogs hunt in coordinated packs in the same manner as chimpanzees and bonobos, and African wild dogs also dig out dens, where one or two females have a large litter.
These remarkable canids, although having adopted the rarest and most difficult preadaptation, have not reached full eusociality, with a worker caste or even ape-level intelligence. They cannot make tools. They lack grasping hands and soft-tipped fingers. They remain four-legged, dependent on their carnassial teeth and fur-sheathed claws.
These hominid primates of two million years ago were diverse, yet no more so than the antelopes and circopithecoid monkeys teeming around them. They were rich in potential—as our own presence bears witness. Nevertheless, from one generation to the next their continued existence was precarious. Their populations were sparse in comparison with the large herbivores, and they were less abundant than some of the human-sized carnivores that hunted them.
Smaller mammals on average were able to buffer themselves better than large mammals, including humans, against extreme environmental changes. Their methods included burrowing, hibernation, and prolonged torpor, adaptations not available to large mammals. Paleontologists have determined that the turnover in species is still higher in mammals that form social groups. They have pointed out that social groups tend to stay apart from each other during breeding, thus creating smaller populations, making them subject to both quicker genetic divergence and higher extinction rates.
As continental glaciers advanced south across Eurasia, Africa suffered a period of prolonged drought and cooling. Much of the continent was covered by arid grassland and desert. In these times of stress the death of a few thousand individuals, possibly even just a few hundred, could have snapped the line to Homo sapiens altogether.
What drove the hominins on through to larger brains, higher intelligence, and thence language-based culture? That, of course, is the question of questions.
One of the australopith species shifted to the consumption of meat. More precisely, it became omnivorous by adding meat to an already existing vegetable and fruit diet.
Homo habilis became smarter than the other hominins around them.
Perhaps, the traditional argument goes, the challenges of new environments gave an advantage to genetic types able to discover and use novel resources to avoid enemies, as well as the capacity to defeat competitors for food and space. Those genetic types were able to innovate and learn from their competitors. They were the survivors of hard times. The flexible species evolved larger brains. How well does this familiar innovation-adaptiveness describe other animal species? One analysis made of 600 bird species introduced by humans into parts of the world outside their native ranges, and hence into alien environments, seems to support the idea. Those species with larger brains relative to their body size were on average better able to establish themselves in the new environments. Further, there is evidence that it was done by greater intelligence and inventiveness.
Every other kind of animal known that evolved eusociality started with a protected nest from which forays can be made to collect food. Other species of relatively large animals that have advanced almost as far as ants into eusociality are the naked mole rats (Heterocephalus glaber) of East Africa. They, too, obey the protected-nest principle.
It seems now possible to draw a reasonably good explanation of why the human condition is a singularity, why the likes of it has occurred only once and took so long in coming. The reason is simply the extreme improbability of the pre-adaptations necessary for it to occur at all. Each of these evolutionary steps has been a full-blown adaptation in its own right. Each has required a particular sequence of one or more pre-adaptations that occurred previously. Homo sapiens is the only species of large mammal—thus large enough to evolve a human-sized brain—to have made every one of the required lucky turns in the evolutionary maze. The first preadaptation was existence on the land. Progress in technology beyond knapped stones and wooden shafts requires fire.
The second preadaptation was a large body size, of a magnitude attained in Earth’s history only by a minute percentage of land-dwelling animal species. If an animal at maturity is less than a kilogram in weight, its brain size would be too severely limited for advanced reasoning and culture. Even on land, its body would be unable to make and control fire. That is one reason why leafcutter ants, although the most complex of any species other than humans, and even though they practice agriculture in air-conditioned cities of their own instinctual devising, have made no significant further advance during the twenty million years of their existence. Next in line of pre-adaptations was the origin of grasping hands tipped with soft spatulate fingers that were evolved to hold and manipulate detached objects. This is the trait of primates that distinguishes them from all other land-dwelling mammals.
To use such hands and fingers effectively, candidate species on the path to eusociality had to free them from locomotion in order to manipulate objects easily and skillfully. That was accomplished early by the first prehominids who, as far back as when our presumed ancient forebear Ardipithecus, climbed out of the trees, stood up, and began walking entirely on hind legs.
Claws and fangs, the ordinary armamentaria of the species, are ill suited for the development of technology.
The subsequent step—the next correct turn in the evolutionary maze—was a shift in diet to include a substantial amount of meat. Theadvantages of cooperation in the harvesting of meat led to the formation of highly organized groups.
About a million years ago the controlled use of fire followed, a unique hominid achievement. Meat, fire, and cooking, campsites lasting for more than a few days at a time, and thus persistent enough to be guarded as a refuge, marked the next vital step. Such a nest, as it can also be called, has been the precursor to the attainment of eusociality by all other known animals. With fireside campsites came a division of labor.
By the time of Homo erectus, all of the steps that led this species to eusociality, save the use of controlled fire, had also been followed by modern chimpanzees and bonobos. Thanks to our unique pre-adaptations, we were ready to leave these distant cousins far behind.
Even though tiny in biomass—all of its more than seven billion members could be log-stacked into a cube two kilometers on each edge—the new species had become a geophysical force. They had harnessed the energies of the sun and fossil fuel, diverted a large part of the fresh water for their own use, acidified the ocean, and changed the atmosphere to a potentially lethal state.
The origin of modern humanity was a stroke of luck—good for our species for a while, bad for most of the rest of life forever.
Kin selection says parents, offspring, and their cousins and other collateral relatives are bound by the coordination and unity of purpose made possible by selfless acts toward one another. Altruism actually benefits each group member on average because each altruist shares genes by common descent with most other members of its group. Due to the sharing with relatives, its sacrifice increases the relative abundance of these genes in the next generation. If the increase is greater than the average number lost by reducing the number of genes passed on through personal offspring, then the altruism is favored and a society can evolve. Individuals divide themselves into reproductive and nonreproductive castes as a manifestation in part of self-sacrificing behavior on behalf of kin.
The foundations of the general theory of inclusive fitness based on the assumptions of kin selection have crumbled, while evidence for it has grown equivocal at best. The beautiful theory never worked well anyway, and now it has collapsed. A new theory of eusocial evolution provides separate accounts for the origin of eusocial insects on the one hand and the origin of human societies on the other. In the case of ants and other eusocial invertebrates, the process is perceived as neither kin selection nor group selection, but individual-level selection, from queen (in the case of ants and other hymenopteran insects) to queen, with the worker caste being an extension of the queen phenotype. Evolution can proceed in this manner because in the early stages of colonial evolution the queen travels far away from her natal colony and creates the members of the colony on her own.
The creation of new groups by humans, at the present time and all the way back into prehistory, has been fundamentally different. Their evolutionary dynamics is driven by both individual and group selection.
The multilevel process was first anticipated by Darwin in The Descent of Man: if one man in a tribe, more sagacious than the others, invented a new snare or weapon, or other means of attack or defense, the plainest self-interest, without the assistance of much reasoning power, would prompt the other members to imitate him; and all would thus profit. The habitual practice of each new art must likewise in some slight degree strengthen the intellect. If the new invention were an important one, the tribe would increase in number, spread, and supplant other tribes. In a tribe thus rendered more numerous there would always be a rather better chance of the birth of other superior and inventive members. If such men left children to inherit their mental superiority, the chance of the birth of still more ingenious members would be somewhat better, and in a very small tribe decidedly better. Even if they left no children, the tribe would still include their blood-relations; and it has been ascertained by agriculturists that by preserving and breeding from the family of an animal, which when slaughtered was found to be valuable, the desired character has been obtained. Multilevel selection consists of the interaction between forces of selection that target traits of individual members and other forces of selection that target traits of the group as a whole. The new theory is meant to replace the traditional theory based on pedigree kinship or some comparable measure of genetic relatedness.
The precursors of Homo sapiens, formed well-organized groups that competed with one another for territory and other scarce resources. In general, it is to be expected that between-group competition affects the genetic fitness of each member (that is, the proportion of personal offspring it contributes to the group’s future membership), whether up or down. A person can die or be disabled, and lose his individual genetic fitness as a result of increased group fitness during, for example, a war or under the rule of an aggressive dictatorship. If we assume that groups are approximately equal to one another in weaponry and other technology, which has been the case for most of the time among primitive societies over hundreds of thousands of years, we can expect that the outcome of between-group competition is determined largely by the details of social behavior within each group in turn. These traits are the size and tightness of the group, and the quality of communication and division of labor among its members. Such traits are heritable to some degree; in other words, variation in them is due in part to differences in genes among the members of the group, hence also among the groups themselves. The genetic fitness of each member, the number of reproducing descendants it leaves, is determined by the cost exacted and benefit gained from its membership in the group. These include the favor or disfavor it earns from other group members on the basis of its behavior. The currency of favor is paid by direct reciprocity and indirect reciprocity, the latter in the form of reputation and trust. How well a group performs depends on how well its members work together, regardless of the degree by which each is individually favored or disfavored within the group.
The genetic fitness of a human being must therefore be a consequence of both individual selection and group selection. But this is true only with reference to the targets of selection. Whether the targets are traits of the individual working in its own interest, or interactive traits among group members in the interest of the group, the ultimate unit affected is the entire genetic code of the individual. If the benefit from group membership falls below that from solitary life, evolution will favor departure or cheating by the individual. Taken far enough, the society will dissolve. If personal benefit from group memberships rises high enough or, alternatively, if selfish leaders can bend the colony to serve their personal interests, the members will be prone to altruism and conformity. Because all normal members have at least the capacity to reproduce, there is an inherent and irremediable conflict in human societies between natural selection at the individual level and natural selection at the group level.
Alleles (the various forms of each gene) that favor survival and reproduction of individual group members at the expense of others are always in conflict with alleles of the same and alleles of other genes favoring altruism and cohesion in determining the survival and reproduction of individuals. Selfishness, cowardice, and unethical competition further the interest of individually selected alleles, while diminishing the proportion of altruistic, group-selected alleles. These destructive propensities are opposed by alleles predisposing individuals toward heroic and altruistic behavior on behalf of members of the same group. Group-selected traits typically take the fiercest degree of resolve during conflicts between rival groups. It was therefore inevitable that the genetic code prescribing social behavior of modern humans is a chimera. One part prescribes traits that favor success of individuals within the group. The other part prescribes the traits that favor group success in competition with other groups.
Natural selection at the individual level, with strategies evolving that contribute maximum number of mature offspring, has prevailed throughout the history of life. It typically shapes the physiology and behavior of organisms to suit a solitary existence, or at most to membership in loosely organized groups. The origin of eusociality, in which organisms behave in the opposite manner, has been rare in the history of life because group selection must be exceptionally powerful to relax the grip of individual selection. Only then can it modify the conservative effect of individual selection and introduce highly cooperative behavior into the physiology and behavior of the group members. The ancestors of ants and other hymenopterous eusocial insects (ants, bees, wasps) faced the same problem as those of humans. They finessed it by evolving extreme plasticity of certain genes, programmed so that the altruistic workers have the same genes for physiology and behavior as the mother queen, even though they differ drastically from the queen and among one another in these traits. Selection has remained at the individual level, queen to queen. Yet selection in the insect societies continues at the group level, with colony pitted against colony. This seeming paradox is easily resolved. As far as natural selection in most forms of social behavior is concerned, the colony is operationally only the queen and her phenotypic extension in the form of robot-like assistants. At the same time, group selection promotes genetic diversity among the workers in other parts of the genome to help protect the colony from disease. This diversity is provided by the male with whom each queen mates. In this sense, the genotype of an individual is a genetic chimera. It contains genes that do not vary among colony members, with castes being plastic forms created from the same genes, and genes that do vary among colony members as a shield against disease.
In mammals such a finesse was not possible, because their life cycle is fundamentally different from that of insects. In the key reproductive step of the mammal life cycle, the female is rooted to the territory of her origin. She cannot separate herself from the group in which she was born, unless she crosses over directly to a neighboring group—a common but tightly controlled event in both animals and humans. In contrast, the insect female can be mated, then carry the sperm like a portable male in her spermatheca long distances. She is able to start new colonies all by herself far from the nest of her birth. The overpowering of individual selection by group selection has not only been rare in mammals and other vertebrates; it has never been and will likely never be complete. The fundamentals of the mammalian life cycle and population structure prevent it. No insect-like social system can be created in the theater of mammalian social evolution.
The expected consequences of this evolutionary process in humans are the following:
• Intense competition occurs between groups, in many circumstances including territorial aggression.
• Group composition is unstable, because of the advantage of increasing group size accruing from immigration, ideological proselytization, and conquest, pitted against the opportunities to gain advantage by usurpation within the group and fission to create new groups.
• An unavoidable and perpetual war exists between honor, virtue, and duty, the products of group selection, on one side, and selfishness, cowardice, and hypocrisy, the products of individual selection, on the other side.
• The perfecting of quick and expert reading of intention in others has been paramount in the evolution of human social behavior.
• Much of culture, including especially the content of the creative arts, has arisen from the inevitable clash of individual selection and group selection.
In summary, the human condition is an endemic turmoil rooted in the evolution processes that created us. The worst in our nature coexists with the best, and so it will ever be. To scrub it out, if such were possible, would make us less than human.
To form groups, drawing visceral comfort and pride from familiar fellowship, and to defend the group enthusiastically against rival groups—these are among the absolute universals of human nature and hence of culture. Once a group has been established with a defined purpose, however, its boundaries are malleable. Families are usually included as subgroups, although they are frequently split by loyalties to other groups. The same is true of allies, recruits, converts, honorary inductees, and traitors from rival groups who have crossed over. Identity and some degree of entitlement are given each member of a group. Conversely, any prestige and wealth he may acquire lends identity and power to his fellow members.
People must have a tribe. It gives them a name in addition to their own and social meaning in a chaotic world. It makes the environment less disorienting and dangerous. The social world of each modern human is not a single tribe, but rather a system of interlocking tribes, among which it is often difficult to find a single compass. People savor the company of like-minded friends, and they yearn to be in one of the best—a combat marine regiment, perhaps, an elite college, the executive committee of a company, a religious sect, a fraternity, a garden club—any collectivity that can be compared favorably with other, competing groups of the same category.
People around the world today, growing cautious of war and fearful of its consequences, have turned increasingly to its moral equivalent in team sports. Their thirst for group membership and superiority of their group can be satisfied with victory by their warriors in clashes on ritualized battlefields. The fans are lifted by seeing the uniforms and symbols and battle gear of the team, the championship cups and banners on display, the dancing seminude maidens appropriately called cheerleaders. Some of the fans wear bizarre costumes and face makeup in homage to their team. They attend triumphant galas after victories. Many, especially of warrior and maiden age, shed all restraint to join in the spirit of the battle and the joyous mayhem afterward.
“Celts Supreme!” The social psychologist Roger Brown, who witnessed the aftermath, commented, “It was not just the players who felt supreme but all their fans. There was ecstasy in the North End. The fans burst out of the Garden and nearby bars, practically break dancing in the air, stogies lit, arms uplifted, voices screaming. The hood of a car was flattened, about thirty people jubilantly piled aboard, and the driver—a fan—smiled happily. An improvised slow parade of honking cars circled through the neighborhood. It did not seem to me that those fans were just sympathizing or empathizing with their team. They personally were flying high. On that night each fan’s self-esteem felt supreme; a social identity did a lot for many personal identities.” Brown then added an important point: “Identification with a sports team has in it something of the arbitrariness of the minimal groups. To be a Celtic fan you need not be born in Boston or even live there, and the same is true of membership on the team. As individuals, or with other group memberships salient, both fans and team members might be very hostile. So long as the Celtic membership was salient, however, all rode the waves together.”
Experiments conducted over many years by social psychologists have revealed how swiftly and decisively people divide into groups, and then discriminate in favor of the one to which they belong. Even when the experimenters created the groups arbitrarily, then labeled them so the members could identify themselves, and even when the interactions prescribed were trivial, prejudice quickly established itself. Whether groups played for pennies or identified themselves groupishly as preferring some abstract painter to another, the participants always ranked the out-group below the in-group. They judged their “opponents” to be less likable, less fair, less trustworthy, less competent. The prejudices asserted themselves even when the subjects were told the in-groups and out-groups had been chosen arbitrarily.
In its power and universality, the tendency to form groups and then favor in-group members has the earmarks of instinct. It could be argued that in-group bias is conditioned by early training to affiliate with family members and by encouragement to play with neighboring children. But even if such experience does play a role, it would be an example of what psychologists call prepared learning, the inborn propensity to learn something swiftly and decisively. If the propensity toward in-group bias has all these criteria, it is likely to be inherited and, if so, can be reasonably supposed to have arisen through evolution by natural selection. Other cogent examples of prepared learning in the human repertoire include language, incest avoidance, and the acquisition of phobias. If groupist behavior is truly an instinct expressed by inherited prepared learning, we might expect to find signs of it even in very young children. And exactly this phenomenon has been discovered by cognitive psychologists.
The elementary drive to form and take deep pleasure from in-group membership easily translates at a higher level into tribalism. People are prone to ethnocentrism. It is an uncomfortable fact that even when given a guilt-free choice, individuals prefer the company of others of the same race, nation, clan, and religion. They trust them more, relax with them better in business and social events, and prefer them more often than not as marriage partners. They are quicker to anger at evidence that an out-group is behaving unfairly or receiving undeserved rewards. And they grow hostile to any out-group encroaching upon the territory or resources of their in-group.
Literature and history are strewn with accounts of what happens at the extreme, as in the following from Judges 12: 5–6 in the Old Testament: The Gileadites captured the fords of the Jordan leading to Ephraim, and whenever a survivor of Ephraim said, “Let me go over,” the men of Gilead asked him, “Are you an Ephraimite?” If he replied, “No,” they said, “All right, say ‘Shibboleth.’ ” If he said, “Sibboleth,” because he could not pronounce the word correctly, they seized him and killed him at the fords of the Jordan. Forty-two thousand Ephraimites were killed at that time.
When in experiments black and white Americans were flashed pictures of the other race, their amygdalas, the brain’s center of fear and anger, were activated so quickly and subtly that the conscious centers of the brain were unaware of the response. The subject, in effect, could not help himself. When, on the other hand, appropriate contexts were added—say, the approaching black was a doctor and the white his patient—two other sites of the brain integrated with the higher learning centers, the cingulate cortex and the dorsolateral preferential cortex, lit up, silencing input through the amygdala. Thus different parts of the brain have evolved by group selection to create groupishness.
Our bloody nature, it can now be argued in the context of modern biology, is ingrained because group-versus-group was a principal driving force that made us what we are. In prehistory, group selection lifted the hominids that became territorial carnivores to heights of solidarity, to genius, to enterprise. And to fear. Each tribe knew with justification that if it was not armed and ready, its very existence was imperiled. Throughout history, the escalation of a large part of technology has had combat as its central purpose. Today, the calendars of nations are punctuated by holidays to celebrate wars won and to perform memorial services for those who died waging them. Public support is best fired up by appeal to the emotions of deadly combat,
Any excuse for a real war will do, so long as it is seen as necessary to protect the tribe. Hence the war against terrorism and axis of evil. Remembrance of past horrors has no effect.
From April to June in 1994, killers from the Hutu majority in Rwanda set out to exterminate the Tutsi minority, which at that time ruled the country. In a hundred days of unrestrained slaughter by knife and gun, 800,000 people died, mostly Tutsi. The total Rwandan population was reduced by 10%. When a halt was finally called, two million Hutu fled the country, fearing retribution.
The immediate causes for the bloodbath were political and social grievances, but they all stemmed from one root cause: Rwanda was the most overcrowded country in Africa. For a relentlessly growing population, the per capita arable land was shrinking toward its limit. The deadly argument was over which tribe would own and control the whole of it. Many of those who attacked their neighbors were promised the land of the Tutsi they killed.
Once a group has been split off and sufficiently dehumanized, any brutality can be justified, at any level, and at any size of the victimized group up to and including race and nation. Russia’s Great Terror under Stalin resulted in the deliberate starvation to death of more than three million Soviet Ukrainians during the winter of 1932–33. In 1937 and 1938, 681,692 executions were carried out for alleged “political crimes,” of which more than 90% were peasants considered resistant to collectivization. The U.S.S.R. as a whole soon itself suffered equally from the brutal Nazi invasion, the stated purpose of which was to subdue the “inferior” Slavs and make room for expansion of the racially “pure” Aryan peoples.
If no other reason is convenient for waging a war of territorial expansion, there has always been God. It was the will of God that brought the Crusaders to the Levant.
It should not be thought that war, often accompanied by genocide, is a cultural artifact of a few societies. Nor has it been an aberration of history, a result of the growing pains of our species’ maturation. Wars and genocide have been universal and eternal, respecting no particular time or culture. Since the end of the Second World War, violent conflict between states has declined drastically, owing in part to the nuclear standoff of the major powers (two scorpions in a bottle writ large). But civil wars, insurgencies, and state-sponsored terrorism continue unabated. Overall, big wars have been replaced around the world by small wars of the kind and magnitude more typical of hunter-gatherer and primitively agricultural societies. Civilized societies have tried to eliminate torture, execution, and the murder of civilians, but those fighting little wars do not comply.
If cooperative groups were more likely to prevail in conflicts with other groups, has the level of intergroup violence been sufficient to influence the evolution of human social behavior? The estimates of adult mortality in hunter-gatherer groups from the beginning of Neolithic times to the present, shown in the accompanying table, support that proposition. Nonlethal violence is far higher in the chimps, occurring between a hundred and possibly a thousand times more often than in humans.
Males are more gregarious than females. They are also intensely status conscious, frequently engaging in displays that lead to fighting. They form coalitions with others and use a wide array of maneuvers and deceptions to exploit or altogether evade the dominance order. The patterns of collective violence in which young chimp males engage are remarkably similar to those of young human males. Aside from constantly vying for status, both for themselves and for their gangs, they tend to avoid open mass confrontations with rival troops, instead relying on surprise attacks. The purpose of raids made by the male gangs on neighboring communities is evidently to kill or drive out its members and acquire new territory.
Uganda’s Kibale National Park. The war, conducted over ten years, was eerily human-like. Every 10 to 14 days, patrols of up to 20 males penetrated enemy territory, moving quietly in single file, scanning the terrain from ground to the treetops, and halting cautiously at every surrounding noise. If a force larger than their own was encountered, the invaders broke rank and ran back to their own territory. When they encountered a lone male, however, they piled on him in a crowd and pummeled and bit him to death. When a female was encountered, they usually let her go. This latter tolerance was not a display of gallantry. If she carried an infant, they took it from her and killed and ate it.
There is no certain way to decide on the basis of existing knowledge whether chimpanzee and humans inherited their pattern of territorial aggression from a common ancestor or whether they evolved it independently in response to parallel pressures of natural selection and opportunities encountered in the African homeland. Humans and chimpanzees are intensely territorial. That is the apparent population control hardwired into their social systems.
I believe, however, that the evidence best fits the following sequence. The original limiting factor, which intensified with the introduction of group hunting for animal protein, was food. Territorial behavior evolved as a device to sequester the food supply. Expansive wars and annexation resulted in enlarged territories and favored genes that prescribe group cohesion, networking, and the formation of alliances. For hundreds of millennia, the territorial imperative gave stability to the small, scattered communities of Homo sapiens, just as they do today in the small, scattered populations of surviving hunter-gatherers. During this long period, randomly spaced extremes in the environment alternately increased and decreased the population size that could be contained within territories. These “demographic shocks” led to forced emigration or aggressive expansion of territory size by conquest, or both together. They also raised the value of forming alliances outside of kin-based networks in order to subdue other neighboring groups.
Ten thousand years ago, the Neolithic revolution began to yield vastly larger amounts of food from cultivated crops and livestock, allowing rapid growth in human populations. But that advance did not change human nature. People simply increased their numbers as fast as the rich new resources allowed. As food again inevitably became the limiting factor, they obeyed the territorial imperative. Their descendants have never changed. At the present time, we are still fundamentally the same as our hunter-gatherer ancestors, but with more food and larger territories. Region by region, recent studies show, the populations have approached a limit set by the supply of food and water. And so it has always been for every tribe, except for the brief periods after new lands were discovered and its indigenous inhabitants displaced or killed. The struggle to control vital resources continues globally, and it is growing worse. The problem arose because humanity failed to seize the great opportunity given it at the dawn of the Neolithic.
Homo erectus, with a culture advanced well beyond that of its apish ancestors, and more adaptable to new and difficult environments, expanded its range to become the first cosmopolitan primate. It failed to reach only the isolated continents of Australia and the New World and the far-flung archipelagoes of the Pacific Ocean. Its great range buffered the species against early extinction. One of its genetic lines acquired potential immortality by evolving into Homo sapiens. The ancestral Homo erectus still lives. It is us.
In combination, some of our traits are unique among all animals:
- A productive language based on infinite permutations of arbitrarily invented words and symbols.
- Music, comprising a wide array of sounds, also in infinite permutations and played in individually chosen mood-creating patterns; but, most definitively, with a beat.
- Prolonged childhood, allowing extended learning periods under the guidance of adults.
- Anatomical concealment of female genitalia and the abandonment of advertisement of ovulation, both combined with continuous sexual activity. The latter promotes female-male bonding and biparental care, which are needed through the long period of helplessness in early childhood.
- Uniquely fast and substantial growth in the brain size during early development, increasing 3.3 times from birth to maturity.
- Relatively slender body form, small teeth, and weakened jaw muscles, indicative of an omnivorous diet.
- A digestive system specialized to eat foods that have been tenderized by cooking.
Perhaps the time has come, in light of this and other advances in human genetics, to adopt a new ethic of racial and hereditary variation, one that places value on the whole of diversity rather than on the differences composing the diversity. It would give proper measure to our species’ genetic variation as an asset, prized for the adaptability it provides all of us during an increasingly uncertain future. Humanity is strengthened by a broad portfolio of genes that can generate new talents, additional resistance to diseases, and perhaps even new ways of seeing reality. For scientific as well as for moral reasons, we should learn to promote human biological diversity for its own sake instead of using it to justify prejudice and conflict.
This scenario of slow initial advance by a very few followed by local population growth is supported by two lines of evidence assembled by independent groups of researchers during the past ten years. First is the great genetic diversity of present-day southern Africans, suggesting that only a small part of the whole African population participated in the breakout.
To envision more precisely how the out-of-Africa pattern began, between 135,000 and 90,000 years ago, a period of aridity gripped tropical Africa far more extreme than any that had been experienced for tens of millennia previously. The result was the forced retreat of early humanity to a much smaller range and its fall to a perilously low level in population. Death by starvation and tribal conflict, both of which were to become routine in later historical times, must have been widespread in prehistory. The size of the total Homo sapiens population on the African continent descended into the thousands, and for a long while the future conqueror species risked complete extinction.
Then, finally, the great drought eased, and from 90,000 to 70,000 years ago tropical forests and savanna slowly expanded back to their previous ranges. Human populations grew and spread with them. At the same time, other parts of the continent became more arid, and the Middle East as well. With intermediate levels of rainfall prevailing throughout most of Africa, an especially favorable window of opportunity opened for the demographic expansion of pioneer populations out of the continent altogether. In particular, the interval was long enough to maintain a corridor of continuous habitable terrain up the Nile to Sinai and beyond, bisecting the arid land and allowing a northward sweep of colonizing humans. A second possible route was eastward, across the Bab el Mandeb Strait onto the southern Arabian Peninsula. There followed the penetration of Homo sapiens into Europe by no later than 42,000 years before the present. Anatomically modern humans spread up the Danube River,
The question of exactly when anatomically modern Homo sapiens arrived in the New World, with its catastrophic impact on the virgin fauna and flora, has gripped the attention of anthropologists for many years. From genetic and archaeological studies across Siberia and the Americas, it now appears that a single Siberian population reached the Bering land bridge no sooner than 30,000 years ago, and possibly as recently as 22,000 years. Around 16,500 years before the present, the retreat of the ice sheets cleared the way south, and a full-scale invasion through Alaska began. By 15,000 years before the present, as revealed by archaeological discoveries in both North and South America, the colonization of the Americas was well under way. It appears likely that the first populations dispersed along the recently deglaciated Pacific coastline, along land still exposed by the incomplete withdrawal of the ice sheets but nowadays mostly underwater.
A more realistic view is that the creative explosion was not a single genetic event but the culmination of a gradual process that began in an archaic form of Homo sapiens as far back as 160,000 years. This view has been supported by recent discoveries of the use of pigment that old, as well as personal ornaments and abstract design scratched on bone and with ocher dating from between 100,000 and 70,000 years ago.
For the immediate future, however, emigration and ethnic intermarriage have taken over as the overwhelmingly dominant forces of microevolution, by homogenizing the global distribution of genes. The impact on humanity as a whole, even while still in this current early stage, is an unprecedented dramatic increase in the genetic variation within local populations around the world. The increase is matched by a reduction in differences between populations. Theoretically, if the flow continues long enough, the population of Stockholm could come to be the same genetically as that in Chicago or Lagos. Overall, more kinds of genotypes are being produced everywhere. This change, unique in human evolutionary history, offers a prospect of an immense increase in different kinds of people worldwide, and thereby newly created physical beauty and artistic and intellectual genius.
With all its quirks, irrationality, and risky productions, and all its conflict and inefficiency, the biological mind is the essence and the very meaning of the human condition.
Chiefs or “big men” rule by prestige, largesse, the support of elite members below them—and retribution against those who oppose them. They live on the surplus accumulated by the tribe, employing it to tighten control upon the tribe, to regulate trade, and to wage war with neighbors. Chiefs exercise authority only on the people immediately around them or in nearby villages, with whom they interact as needed on a daily basis. In practice this means subjects who can be reached within half a day traveling by foot. The reach is thus a maximum of 25 to 30 miles. It is to the advantage of chiefs to micromanage the affairs of their domain, delegating as little authority as possible in order to reduce the chance of insurrection or fission. Common tactics include the suppression of underlings and the fomenting of fear of rival chiefdoms.
States, the final step up in the cultural evolution of societies, have a centralized authority. Rulers exercise their authority in and around the capital, but also over villages, provinces, and other subordinate domains beyond the distance of a one day’s walk, hence beyond immediate communication with the rulers. The domain is too far-flung, the social order and communication system holding it together too complex, for any one person to monitor and control. Local power is therefore delegated to viceroys, princes, governors, and other chief-like rulers of the second rank. The state is also bureaucratic. Responsibility is divided among specialists, including soldiers, builders, clerks, and priests. With enough population and wealth, the public services of art, sciences, and education can be added—first for the benefit of the elite and then, trickling down, for the general public. The heads of state sit upon a throne, real or virtual. They ally themselves with the high priests, and clothe their authority with rituals of allegiance to the gods.
There are five basic human personality traits: extroversion versus introversion, antagonism versus agreeableness, conscientiousness, neuroticism, and openness to experience. Within populations each of these domains contains substantial heritability, mostly falling between one-third to two-thirds. This means that of the total variation of scores in each domain—the fraction due to differences in genes among individuals—falls somewhere between one-third and two-thirds. So from inheritance alone we would expect to find substantial variation in a population such as that in the Burkina Faso village. Added to differences in experience from one person to the next, especially during the formative periods of childhood, we should expect to find even greater variation, but more or less consistently from village to village, and from country to country. Does such substantial variation exist universally, and is it the same from one population to the next, or different? The variation turns out to be consistently great and universally to the same degree across populations. Such was the result of an extraordinary study conducted by a team of 87 researchers and published in 2005. The degree of variation in personality scores was similar across all of 49 cultures measured. The central tendencies of the five domains of personality differed only slightly from one to the next, in a way that was not consistent with prevailing stereotypes held by those outside the cultures.
It is highly unlikely that primary states emerged around the world as the result of convergent genetic evolution. It is all but certain that they appeared autonomously as elaborations of already existing genetic predispositions shared by human populations through common ancestry and dating back to the breakout period some 60,000 years ago.
Animals of the land environment are dominated by species with the most complex social systems. The second phenomenon is that these species have evolved only rarely in evolution.
The most complex systems are those possessing eusociality—literally “true social condition.” Members of a eusocial animal group, such as a colony of ants, belong to multiple generations. They divide labor in what outwardly at least appears to be an altruistic manner. Some take labor roles that shorten their life spans or reduce the number of their personal offspring, or both. Their sacrifice allows others who fill reproductive roles to live longer and produce proportionately more offspring. The sacrifices within the advanced societies go far beyond those between parents and their offspring. They extend to collateral relatives, including siblings, nieces, and nephews, and cousins at various degrees of remove. Sometimes they are bestowed on genetically unrelated individuals. A eusocial colony has marked advantages over solitary individuals competing for the same niche. Some of the colony members can search for food while others protect the nest from enemies. A solitary competitor belonging to another species can either hunt for food or defend its nest, but not do both at the same time. The colony can send out multiple foragers and stay home all at the same time, forming a webwork of surveillance both within and around the nest. When food is found by one colony member, it can inform the others, who then converge on the site like a closing net. When assembled, the nestmates have the ability to fight as a group against rivals and enemies. They can transport large quantities of food more rapidly to the nest, before competitors arrive. With multiple individuals serving as construction workers, the nest can quickly be made larger, its structure architecturally more efficient, and its entrances more easily defended. The nest can also be climate-controlled to some extent.
Large colonies of some species can also apply military-like formations and mass attacks to overcome prey that are invulnerable to solitary individuals.
The 20,000 known species of eusocial insects, mostly ants, bees, wasps, and termites, account for only 2% of the approximately one million known species of insects. Yet this tiny minority of species dominate the rest of the insects in their numbers, their weight, and their impact on the environment.
I have very crudely estimated the number of ants living today to be, at the nearest power of ten, 1016, ten thousand trillion. If each ant on average weighs one-millionth as each human on average, then, because there are a million times more ants than humans (at 1010), all the ants living on Earth weigh roughly as much as all the humans. This figure is not so impressive as it may sound. Consider: if every living person could be collected and log-stacked, we would make a cube less than one mile on each side. So if all the ants could be similarly collected and log-stacked, they would make a cube of similar size.
Eusociality, the condition of multiple generations organized into groups by means of an altruistic division of labor, was one of the major innovations in the history of life. It created superorganisms, the next level of biological complexity above that of organisms. It is comparable in impact to the conquest of land by aquatic air-breathing animals. It is equivalent in importance to the invention of powered flight by insects and vertebrates.
But the achievement has presented a puzzle not yet solved in evolutionary biology: the rarity of its occurrence.
In the last part of the Jurassic period, some 175 million years ago, the first termites, primitively cockroach-like in anatomy, appeared, followed about 25 million years later by ants. Even then, and continuing to the present time, the origin of other eusocial insects, or eusocial animals of any kind, has been rare. Today there are approximately 2,600 recognized taxonomic families of insects and other arthropods, such as the common fruit flies of the family Drosophilidae, orb-weaving spiders of the family Argiopidae, and land crabs of the family Grapsidae. Only 15 of the 2,600 families are known to contain eusocial species. Six of the families are termites, all of which appear to have been descended from a single eusocial ancestor. Eusociality arose in ants once, three times independently in wasps, and at least four times—probably more, but it is hard to tell—in bees.
A single case of eusociality is known in ambrosia beetles, and others have been discovered in aphids and thrips. Amazingly, eusocial behavior has originated three times in shrimps of the genus Synalpheus of the family Alphaeidae, which build nests in marine sponges. Such rare or relatively unstable originations could easily have gone undetected in the fossil record. Also, the multiplicity of eusocial origins in the Synalpheus shrimps has been discovered only recently.
Still rarer than in the invertebrates has been the appearance of eusociality in the vertebrates. It has occurred twice in the subterranean naked mole rats of Africa. It has occurred once in the line leading to modern humans, and in comparison with the invertebrate origins, only very recently in geological times—as recently as 3 million years ago. It is approached in helper-at-the-nest birds, in which the young remain with the parents for a time, but then either inherit the nest or leave to build one on their own. Eusociality is closely approached by African wild dogs, when an alpha female stays at the den to breed while the pack hunts for prey.
During Mesozoic times many evolving lines of dinosaurs attained at least some of the necessary prerequisites: human-sized, fast-moving carnivores, pack hunters, bipedal gait, and free hands. None took the final step to reach even primitive eusociality.
The sequence had two steps. First, in all of the animal species that have attained eusociality—all of them, without known exception—altruistic cooperation protects a persistent, defensible nest from enemies, whether predators, parasites, or competitors. Second, this step having been attained, the stage was set for the origin of eusociality, in which members of groups belong to more than one generation and divide labor in a way that sacrifices at least some of their personal interests to that of the group.
In the old, conventional image, that of kin selection and the “selfish gene,” the group is an alliance of related individuals that cooperate with one another because they are related. Although potentially in conflict, they nonetheless accede altruistically to the needs of the colony. Workers are willing to surrender some or all of their personal reproductive potential this way because they are kin and share genes with them by common descent. Thus each favors its own “selfish” genes by promoting identical genes that also occur in its fellow group members. Even if it gives its life for the benefit of a mother or sister, such an insect will increase the frequency of genes it shares with the relatives. The genes increased will include those that produced the altruistic behavior. If other colony members behave in similar manner, the colony as a whole can defeat groups composed of exclusively selfish individuals.
Among its basic flaws is that it treats the division of labor between the mother queen and her offspring as “cooperation,” and their dispersal from the mother nest as “defection.” But, as we pointed out, the fidelity to the group and the division of labor are not an evolutionary game. The workers are not players. When eusociality is firmly established, they are extensions of the queen’s phenotype, in other words alternative expressions of her personal genes and those of the male with whom she mated. In effect, the workers are robots she has created in her image that allow her to generate more queens and males than would be possible if she were solitary.
The origin and evolution of eusocial insects can be viewed as processes driven by individual-level natural selection. It is best tracked from queen to queen from one generation to the next, with the workers of each colony produced as phenotypic extensions of the mother queen. The queen and her offspring are often called superorganisms, but they may equally be called organisms. The worker of a wasp colony or ant colony that attacks you when you disturb its nest is a product of the mother queen’s genome. The defending worker is part of the queen’s phenotype, as teeth and fingers are part of your own phenotype. There may immediately seem to be a flaw in this comparison. The eusocial worker, of course, has a father as well as a mother, and therefore partly a different genotype from that of the mother queen. Each colony comprises an array of genomes, while the cells of a conventional organism, being clones, compose only the one genome of the organism’s zygote. Yet the process of natural selection and the single level of biological organization on which its operations occur are essentially the same. Each of us is an organism made up of well-integrated diploid cells. So is a eusocial colony. As your tissues proliferated, the molecular machinery of each cell was either turned on or silenced to create, say, a finger or a tooth. In the same way, the eusocial workers, developing into adults under the influence of pheromones from fellow colony members and other environmental cues, are directed to become one particular caste. It will perform one or a sequence of tasks out of a repertory of potential performances hardwired in the collective brains of the workers. For a period of time, rarely throughout its life, it is a soldier, a nest builder, a nurse, or an all-purpose laborer. Of course, it is a fact that genetic diversity of traits among the workers of eusocial colonies not only exists but functions on behalf of the colony—as documented for disease resistance and climate control of the nest. Would this make the colony a group of individuals, each of whom (in the perspective of kin selection theory) seeks to maximize the fitness of its own genes? That such need not be the case becomes apparent if one views the queen’s genome as consisting of parts relatively low in the variety of its alleles (different forms of each gene) whenever the traits they prescribe need to be inflexible, and yet in the same genome other parts are high in the variety of its alleles whenever those traits need to be flexible. Genetic inflexibility is a necessity of worker caste systems and the means by which they are organized and their personal labor distributed. In contrast, genetic flexibility in worker response is favored in disease resistance by the colony and in climate control inside the nest. The more genetic types that exist in a colony, the more likely that at least a few will survive if a disease sweeps through the nest. And the greater the breadth of sensitivity in detecting deviations from the desired temperature, humidity, and atmosphere, the closer these components of the nest environment can be held to their optimum for life of the colony. There is no important genetic difference between the queen and her daughters in the potential caste they can become. Each fertilized egg, from the moment the queen and male genomes unite, can become either a queen or a worker. Its fate depends on the particularities of the environment experienced by each colony member during its development, including the season in which it is born, the food it eats, and the pheromones it detects. In this sense the workers are robots, produced by the mother queen as ambulatory parts of her phenotype.
A state of conflict often results when workers try to reproduce on their own. The other workers typically thwart the usurpers, thus protecting the queen’s primacy. They may just drive her away from the brood chamber whenever she tries to lay eggs. They may pile on the offender to punish her, perhaps severely enough to cripple or kill her. If she manages to sneak her eggs into the brood chamber, her co-workers recognize their different odor and remove and eat them. [and more about insect colonies not included, as well as why kin selection isn’t true and other detailed complexities of his theory]
Cheaters may win out within a group, gaining a larger share of resources, avoiding dangerous tasks, and breaking rules; but colonies of cheaters lose to colonies of cooperators.
Individual-versus-group selection results in a mix of altruism and selfishness, of virtue and sin among members of a society. If one member devotes its life to service over marriage, the individual is of benefit to society despite no offspring. A soldier going into battle will benefit his country, but runs a higher risk of death than one who doesn’t. a cheater saves his own energy and reduces bodily risk and passes the social cost to others.
Wilson sees controlled fire, bipedal locomotion, hunting and so on as important innovations in human evolution, but not prime movers.
What is human nature?
The very existence of human nature was denied during the last century by most social scientists. They clung to the dogma, in spite of mounting evidence, that all social behavior is learned and all culture is the product of history passed from one generation to the next. Leaders of conservative religions, in contrast, have been prone to believe that human nature is a fixed property vouchsafed by God—to be explained to the masses by those privileged to understand his wishes.
Human nature is not the genes underlying it. They prescribe the developmental rules of the brain, sensory system, and behavior that produce human nature. Nor can the universals of culture found across all societies: age-grading, athletic sports, bodily adornment, calendar, cleanliness training, community organization, cooking, cooperative labor, cosmology, courtship, dancing, decorative art, divination, division of labor, dream interpretation, education, eschatology, ethics, ethnobotany, etiquette, faith healing, family feasting, fire making, folklore, food taboos, funeral rites, games, gestures, gift giving, government, greetings, hair styles, hospitality, housing, hygiene, incest taboos, inheritance rules, joking, kin groups, kinship nomenclature, language, law, luck superstitions, magic, marriage, mealtimes, medicine, obstetrics, penal sanctions, personal names, population policy, postnatal care, pregnancy usages, property rights, propitiation of supernatural beings, puberty customs, religious ritual, residence rules, sexual restrictions, soul concepts, status differentiation, surgery, tool making, trade, visiting, weaving, and weather control.
Human nature is the epigenetic rules, the inherited regularities of mental development. These rules are the genetic biases in the way our senses perceive the world, the symbolic coding by which we represent the world, the options we open to ourselves, and the responses we find easiest and most rewarding psychologically to make. In ways that are beginning to come into focus at the physiological and, in a few cases, the genetic level, the epigenetic rules alter the way we see and linguistically classify color, for example. They determine the individuals we as a rule find sexually most attractive. They cause us to evaluate the aesthetics of artistic design according to degree of complexity. They lead us differentially to acquire fears and phobias concerning dangers in the environment (as from snakes and heights), they induce us to communicate with certain facial expressions and forms of body language, to bond with infants, and so on across a wide range of categories in behavior and thought. Most, like incest avoidance, are evidently very ancient, dating back millions of years in mammalian ancestry. Others, such as the stages of linguistic development, are uniquely human and probably only hundreds of thousands of years old.
The behaviors created by epigenetic rules are not hardwired like reflexes. It is the epigenetic rules instead that are hardwired, and hence compose the true core of human nature. These behaviors are learned, but the process is what psychologists call ‘prepared.’ In prepared learning, we are innately predisposed to learn and thereby reinforce one option over another. We are “counter prepared” to make alternative choices, or even actively to avoid them. For example, we are prepared to learn a fear of snakes very quickly yet not prepared by instinct to treat other reptiles like turtles and lizards with such a degree of revulsion.
The elaboration of culture depends upon long-term memory, and in this capacity humans rank far above all animals. The vast quantity stored in our immensely enlarged forebrains makes us consummate storytellers. We summon dreams and recollections of experience from across a lifetime and use them to create scenarios, past and future. We live in our conscious mind with the consequence of our actions, whether real or imagined. Placed out in alternative versions, our inner stories allow us to override immediate desires in favor of delayed pleasure. By long-range planning we defeat, for a while at least, the urging of our emotions. This inner life is why each person is unique and precious. When one dies, an entire library of both experience and imaginings is extinguished.
The crucial difference between human cognition and that of other animal species, including our closest genetic relatives, the chimpanzees, is the ability to collaborate for the purpose of achieving shared goals and intentions.
Homo erectus advanced to sociality — a level of cooperation among groups. Small groups had begun to establish campsites. They selected defensible sites and fortified them, with some members of the group staying for extended periods to protect the young while others hunted.
The human specialty is intentionality, fashioned from an extremely large working memory. We have become the experts at mind reading, and the world champions at inventing culture. We not only interact intensely with one another, as do other animals with advanced social organizations, but to a unique degree we have added the urge to collaborate. We express our intentions as appropriate to the moment and read those of others brilliantly, cooperating closely and competently to build tools and shelters, to train the young to plan foraging expeditions, to play on teams, to accomplish almost all we need to do to survive as human beings.
Humans are successful not because of an elevated general intelligence that addresses all challenges, but because they are born to be specialists in social skills. By cooperating through the communication and the reading of intention, groups accomplish far more than the effort of any one solitary person.
The highest level of social intelligence was aquired when our ancestors acquired a combination of three particular attributes. They developed shared attention – the tendency to pay attention to the same object as others. They acquired a high level of the awareness they needed to act together to achieve a common goal or thwart others. And they acquired a “theory of mind,” the recognition that their own mental states would be shared by others.
After that, languages comparable to those today were invented at least 60,000 years ago. Language was the trail of human social evolution. It bestowed almost magical powers on the human species by using arbitrary symbols and words to convey meaning and an infinite number of messages. It can express to at least a crude degree everything we can perceive, dream or experience we can imagine, and every mathematical statement our analyses can construct.
Wilson then goes on the explain why the bee waggle dance and other communications of other animals is not a language. Some reasons why human language is are that we can make reference to objects and events not in the vicinity or that even exist. We emphasize particular words to invoke emphasis and mood. We can be indirect and insinuate instead of saying something baldly and leave open plausible deniability.
Turn-taking during conversations turns out to the similar no matter what the culture – the conversational gaps tend to avoid overlap, but not interruption.
Are people innately good, but corruptible by the forces of evil? Or, are they instead innately wicked, and redeemable only by the forces of good? People are both. And so it will forever be unless we change our genes, because the human dilemma was foreordained in the way our species evolved, and therefore an unchangeable part of human nature. Human beings and their social orders are intrinsically imperfectible and fortunately so. In a constantly changing world, we need the flexibility that only imperfection provides.
The dilemma of good and evil was created by multilevel selection, in which individual selection and group selection act together on the same individual but largely in opposition to each other. Individual selection is the result of competition for survival and reproduction among members of the same group. It shapes instincts in each member that are fundamentally selfish with reference to other members. In contrast, group selection consists of competition between societies, through both direct conflict and differential competence at exploiting the environment. Group selection shapes instincts that tend to make individuals altruistic toward one another but not toward members of other groups.
Individual selection is responsible for much of what we call sin, while group selection is responsible for the greater part of virtue. Together they have created the conflict between the poorer and the better angels of our nature.
Individual selection, defined precisely, is the differential longevity and fertility of individuals in competition with other members of the group. Group selection is differential longevity and lifetime fertility of those genes that prescribe traits of interaction among members of the group, having arisen during competition with other groups.
How to think out and deal with the eternal ferment generated by multilevel selection is the role of the social sciences and humanities. How to explain it is the role of the natural science, which if successful, should make the pathways to harmony among the three great branches of learning easier to create. The social sciences and humanities are devoted to the proximate, outwardly expressed phenomena of human sensations and thought. In the same way that descriptive natural history is related to biology, the social sciences and humanities are related to human self-understanding. They describe how individuals feel and act, and with history and drama they tell a representative fraction of the infinite stores that human relationships can generate. All of this, however, exists within a box. It is confined there because sensations and thought are ruled by human nature, and human nature is also in a box. It is only one of a vast number of possible natures that could have evolved. The one we have is the result of the improbably pathway followed across millions of years by our genetic ancestors that finally produced us. To see human nature as the product of this evolutionary trajectory is to unlock the ultimate causes of our sensations and thought. To put together both proximate and ultimate causes is the key to self-understanding, the means to see ourselves as we truly are and then to explore outside the box.
An iron rule exists in social evolution. It is that selfish individuals beat altruistic individuals, while groups of altruists beat groups of selfish individuals. The victory can never be complete; the balance of selection pressures cannot move to either extreme. If individual selection were to dominate, societies would dissolve. If group selection were to dominate, human groups would come to resemble ant colonies.
Each individual is linked to a network of other group members. Its own survival and reproductive capacity are dependent in part on its interaction with others in the network. What counts is the propensity to form the myriad alliances, favors, exchanges of information, and betrayals that make up daily life in the network.
When villages and chiefdoms emerged around 10,000 years ago, the nature of networks changed, growing in size dramatically. Groups became overlapping, hierarchical, and porous. Social existence became far less stable than when we were hunter gatherers. In industrialized nations, networks grow to a complexity that is bewildering to the Paleolithic mind we inherited. Our instincts still desire the tiny, united band-networks, unprepared for civilization.
This trend has thrown confusion into the joining of groups, one of the most powerful human impulses. Every person is a compulsive group-seeker, hence an intensely tribal anima. This need is satisfied in a extended family, organized religion, ideology, ethnic group, or sports club in combination.
To be human is also to level others, especially those who appear to receive more than they have earned. To steer through jealous rivals, people try to be modest in demeanor as a stratagem. And to enhance reputation with reciprocity so that altruism and cooperativeness are achieved, as the expression “do good and talk about it” states. Since everyone knows the game, people are willing to counter it if they can, acutely sensitive to hypocrisy and read to to level those with less than impeccable credentials. Levelers have a formidable armament of roasts, jokes, parodies, and mocking laughter to weaken the haughty and overly ambitious. Some studies suggest that leveling is beneficial. Societies that do best for their citizens in quality of life, from education, medical car, and crime control also have the lowest income differential between the wealthy and poor.
People also enjoy seeing punishment of those who don’t cooperate, the freeloaders and criminals or idle rich. They’re also willing to administer justice, scolding motorists running a red light, whistle-blowing their employer, and so on.
Societies are mistaken to disapprove of homosexuality because gays have different sexual preferences and reproduce less. Their presence should be valued instead for what they contribute constructively to human diversity. A society that condemns homosexuality harms itself.
SCIENCE & RELIGION
The conflict between science and religion began in earnest during the late 20th century when scientists saw humans as a product of evolution by natural selection. By 1998, members of the U.S. National academy of sciences, an elite elected group, were approaching complete atheism. Only 10% testified to a belief in either God or immortality, with just 2% of them biologists.
But in the late 1990s, over 95% of Americans believed in God or some kind of universal life force, and 45% attend church more than once a week. Europeans are puzzled over this widespread biblical literalism and denial, by half the U.S. population, of biological evolution.
The evidence in great abundance points to organized religion as an expression of tribalism. Every religion teaches its adherents that they are a special fellowship and that their creation story, moral precepts, and privilege from divine power are superior to those claimed in other religions. Their charity and other acts of altruism are concentrated on their coreligionists; when extended to outsiders, it is usually to proselytize and strengthen the size of the trip and its allies. No religious leader ever urges people to consider rival religions and choose the one they find best for their person and society. The conflict among religions is often instead an accelerant, if not a direct cause of war. Devout believers value their faith above all else and are quick to anger if it is challenged. The power of organized religious is based upon their contribution to social order and personal security, not the search for truth. Acceptance of bizarre creation myths binds the members together.
[and a great deal more about religion, the arts, music]
Where are we going?
By any conceivable standard, humanity is far and away life’s geat achievement. We are the mind of the biosphere, the solar system, and who can say – perhaps the galaxy. Our ancestors were one of the few to ever evolve eusociality, with group members across two or more generations staying together, cooperating, caring for the young, and dividing labor that favors some over others. We hit upon symbol-based language, literacy, and science-based technology that gave us an edge over the rest of life. We are godlike.
How did we get here? Apparently multilevel natural selection of group and individual selection combined. This is why we are conflicted – feeling the pull of conscience, of heroism against cowardice, of truth against deception, of commitment against withdrawal. It isour fate to be tormented with large and small dilemmas as we daily wind our way through the risky, fractious world that gave us birth. We have mixed feelings. We are not sure of this or that course of action. We know too well that no one is immune from making a catastrophic mistake or any organization free of corruption.
We are pleased to endlessly watch and analyze our relatives, friends, and enemies. Gossip has always been the favorite occupation in every society. To weigh as accurately as possible the intentions and trustworthiness of those who affect us is very human and highly adaptive. And to judge the impact of others on the welfare of the group as a whole. We are geniuses at reading intentions of others as they struggle with their own angels and demons. Civil law is how we moderate the damage of inevitable failures.
Confusion is compounded by humanity living in a largely mythic, spirit-haunted world which we owe to our early history. When our ancestors realized their mortality about 100,000 years ago, they sought an explanation of who they were and the meaning of the world. They must have asked where do the dead go and most decided they went to the spirit world. And we could see the dead again in dreams, with drugs or self-inflicted privation.
The best, the only way our forebears could explain existence was a creation myth, which without exception, affirmed the superiority of the tribe that invented it over all other trips. Every religious believer saw himself as a chosen person. To question the sacred myths is to question the identity and worth of those who believe them. That is why skeptics, even those committed to equally absurd myths, are disliked and can risk imprisonment or death.
Organized religions preside over the rites of passage, from birth to maturity, from marriage to death. They offer the best a tribe has to offer: a committed community that gives heartfelt emotional support, and welcomes, and forgives. These beliefs in immorality and divine justice give comfort and steel resolution and bravery. Religions have been the source of much of the best of creative arts.
Why then is it wise to openly question the myths and gods of organized religions? Because they are stultifying and divisive. Because each is just one version of a competing multitude of scenarios that possibly can be true. Because they encourage ignorance, distract people from recognizing problems of the real world, and often lead them in wrong directions into disastrous actions. True to their biological origins, they passionately encourage altruism within the membership.
A good first step toward the liberation of humanity from the oppressive forms of tribalism would be to repudiate the claims of those in power who say they speak for God, are a special representative of god, or have exclusive knowledge of God’s divine will. Among these purveyors of theological narcissism are would-be prophets, the founders of religious cults, impassioned evangelical minsters, ayatollahs, imams of the grand mosques, chief rabbis, Rosh yeshivas, the Dalai Lama and the pope. The same is true for dogmatic political ideologies based on unchallengeable precepts, left or right, and especially where justified with the dogmas of organized religions.
Another argument for a new Enlightenment is that we are alone on this planet with whatever reason and understanding we can muster, and hence solely responsible for our actions as a species. The planet we have conquered is not just a stop along the way to a better world out there in some other dimension. Surely one moral precept we can agree on is to stop destroying our birthplace, the only home humanity will ever have. The evidence for climate warming, the industrial pollution as the principal cause is now overwhelming. Also evident is the rapid disappearance of tropical forests and grasslands and other habitats where most of the diversity of life exists. Half of living species could be extinct by the end of the century.
Science is not just another enterprise like medicine or engineering or theology. It is the wellspring of all the knowledge we have of the real world that can be tested and fitted to preexisting knowledge. It is the arsenal of technologies and inferential math needed to distinguish the true from the false. It formulates the principles and formulas that tie all this knowledge together. Science belongs to everybody. Its constituent parts can be challenged by anybody in the world who has sufficient information to do so. It is not just another way of knowing, making it coequal with religious faith. The conflict between scientific knowledge and the teachings of organized religions is irreconcilable. The chasm will continue to widen and cause no end of trouble as long as religious leaders go on making unsupportable claims about supernatural causes of reality.