In the last decade of his life, Edward O. Wilson returned to the questions that had occupied him from the beginning — the origin of societies, the puzzle of altruism, the place of humanity in nature — and gave them a bold and controversial new answer. The result was a pair of late books, The Social Conquest of Earth (2012) and Genesis: The Deep Origin of Societies (2019), in which Wilson set out to trace the deep evolutionary origins of advanced social life and, in doing so, revised the very theory of social evolution he had helped to establish. This chapter examines that late synthesis: Wilson's account of how the rare and momentous condition of advanced sociality arose, his provocative parallel between the social insects and human beings, his contested embrace of group selection over the kin-selection theory he had long championed, and his vision of humanity as a conflicted product of these deep evolutionary forces. It was the most disputed episode of his late career, a scientific quarrel of unusual bitterness, and it represented Wilson's final attempt to answer the largest questions about where societies — including our own — come from.
Wilson framed The Social Conquest of Earth around the three great questions the painter Paul Gauguin had inscribed on his Tahitian masterpiece: Where do we come from? What are we? Where are we going? These questions, Wilson proposed, could now be answered — or at least seriously addressed — by evolutionary biology rather than by religion or philosophy alone. His organizing insight was a striking parallel between the two great conquests of the Earth by social life: that of the social insects, whose colonies dominate the invertebrate world, and that of human beings, who dominate the world of large land animals. Both conquests, Wilson argued, were achieved through the same rare and powerful innovation — advanced social organization, in which members of a group cooperate so thoroughly that the group itself becomes a kind of higher-level individual, able to outcompete the merely solitary. The insects and humanity had arrived at ecological dominance by parallel paths, and comparing the two, Wilson believed, could illuminate the deep principles of social evolution that both exemplify.
Central to Wilson's argument was the emphasis he placed on the extraordinary rarity of advanced social organization in the history of life. Eusociality — the condition, defined by cooperative brood care, overlapping generations, and a reproductive division of labor into fertile and sterile castes, that marks the pinnacle of social evolution — has arisen only a handful of times across all the hundreds of millions of years of animal life. By Wilson's count in Genesis, full eusociality evolved independently only about seventeen times, an astonishingly small number given the immense success of the lineages that achieved it. This rarity posed what Wilson called the central scientific dilemma: if advanced sociality is so overwhelmingly successful — if eusocial insects dominate the invertebrate world and humans dominate the vertebrate world — then why has it evolved so seldom? The answer, he argued, is that crossing the threshold into true sociality is extraordinarily difficult, requiring a rare conjunction of circumstances, but that once the threshold is crossed, the resulting societies are so formidable that they sweep to ecological dominance. The rarity of the achievement and the magnitude of its consequences were, for Wilson, the two facts any theory of social evolution had to explain.
Wilson described the crossing of the eusociality threshold as an evolutionary giant leap — a decisive transition, difficult to achieve, after which there is in effect no going back. Once a lineage crosses into full eusociality, with its sterile helper castes and its reproductive division of labor, natural selection begins to act upon the colony as a whole, elaborating the social instincts and the caste systems that make the society formidable. The colony becomes a unit of selection in its own right, and the evolutionary dynamics shift decisively from the individual to the group. This is why the threshold matters so much in Wilson's account: it is not a gradual slope but a genuine barrier, rarely surmounted, but transformative once it is. The difficulty of the leap explains the rarity of eusociality; the power of what lies on the far side explains the dominance of the lineages that manage it. Before the threshold, evolution works on solitary individuals; after it, a new kind of biological individual — the society itself — has come into being, subject to its own selective pressures and capable of its own evolutionary elaboration.
The social insects, having crossed this threshold, went on to a remarkable series of evolutionary inventions that Wilson catalogued with a specialist's admiration. Nest construction, the elaborate architecture of chambers and galleries; the chemical communication systems by which colonies coordinate the activities of thousands of members; the intricate division of labor among worker castes specialized for foraging, defense, nursing, and construction; the agricultural systems of the fungus-growing ants and termites — all were inventions that advanced the social insects toward their domination of the invertebrate world (these are treated in Chapters 2 through 4). The advantages that colonial life confers were, in Wilson's account, decisive: cooperative defense of the nest, the pooling and sharing of food, the buffering of individuals against misfortune, the capacity to mount collective responses far beyond the power of any solitary insect. The colony could do what no individual could, and this collective capability, once the eusocial threshold had unlocked it, propelled ants, termites, bees, and wasps to a dominance of terrestrial invertebrate life out of all proportion to their small number of origins.
The key to crossing the threshold, in Wilson's account, was the nest. He identified the defensible, progressively provisioned nest as the crucible of eusociality — the precondition that made advanced social life possible. A nest is a valuable, defensible resource, a fixed point that concentrates the activities of its occupants and rewards those who remain to defend and provision it rather than dispersing. When circumstances favor offspring staying at the nest to help rear their siblings instead of leaving to reproduce on their own, the door opens to a reproductive division of labor, and eventually to the sterile worker castes that define eusociality. The nest, in other words, sets the stage on which the drama of social evolution can unfold; without a defensible site worth staying for, the cooperation that leads to eusociality never gets started. This emphasis on ecological circumstance — on the nest as the material precondition of sociality — was characteristic of Wilson's mature thinking, grounding the abstract puzzle of altruism in the concrete realities of where and how animals actually live.
Wilson set the origin of societies within a still grander framework: the major transitions of evolution, the sequence of great steps by which life ascended to ever-higher levels of organization. Borrowing the framework associated with the biologists John Maynard Smith and Eörs Szathmáry, Wilson traced a series of such transitions — from independent molecules to the first living cells, from simple cells to the complex eukaryotic cell, from single cells to multicellular organisms, and finally from solitary organisms to societies. At each of these transitions, he argued, the same fundamental thing happens: entities that had previously reproduced independently come together to form a larger cooperative whole, sacrificing some of their individual autonomy for the advantages of the collective. The origin of eusocial societies was, in this view, simply the most recent of these great transitions — the same process that had earlier assembled cells into organisms now assembling organisms into superorganistic societies. Wilson thus placed the humble ant colony, and the human tribe, in the deepest possible evolutionary context, as expressions of a creative principle that had operated throughout the history of life.
The unifying thread running through all these transitions, Wilson insisted, was altruism — and this placed the ancient puzzle of altruism, which had launched his whole career, at the very center of the story of life. At each major transition, he argued, cooperation and self-sacrifice at the lower level made possible the emergence of the higher level: molecules had to cooperate to form cells, cells to form organisms, organisms to form societies, and in each case the lower-level entities had to forgo some of their own reproductive interest for the good of the whole. Altruism, far from being a peripheral anomaly, was thus the engine of evolutionary ascent, the thing that made each new level of organization possible. In Genesis especially, Wilson made this the book's central theme: that altruism and cooperation, not competition alone, are the creative forces in the history of life, the means by which nature has repeatedly climbed to new heights of complexity. It was a striking inversion of the popular image of evolution as nothing but ruthless struggle, and it expressed Wilson's mature conviction that cooperation is as fundamental to life as competition.
Wilson pressed this theme toward a general biological principle: that the most cooperative species tend to become the most ecologically dominant. The connection was, he argued, no accident. Cooperation unlocks capabilities unavailable to the solitary — the coordinated defense, the shared labor, the pooled information that let a group accomplish what no individual could — and these capabilities translate directly into ecological success. The eusocial insects dominate the invertebrate world, and humans dominate the vertebrate world, precisely because they are the most thoroughly cooperative species in their respective domains. Yet Wilson also grappled with a second dilemma this raised: if cooperation is so advantageous, why did the great transitions to higher sociality take so long, and occur so seldom? His answer returned to the difficulty of overcoming the pull of individual selfishness — the perpetual threat that defectors will exploit cooperators and unravel the cooperative whole. The transitions took vast stretches of time, and succeeded only a handful of times, because the obstacle they had to overcome — the temptation of individual advantage at the expense of the group — is formidable and ever-present. That the obstacle was nonetheless overcome, solved repeatedly at the deepest transitions and about seventeen times for eusociality specifically, was for Wilson one of the most remarkable facts in all of biology.
How, though, does altruism itself evolve, when natural selection would seem to punish the self-sacrificing and reward the selfish? This is the dilemma of altruism, and Wilson's answer in his late work marked a dramatic and controversial reversal. For decades, the dominant explanation — which Wilson himself had done much to promote — had been kin selection, the theory that altruism evolves because it benefits relatives who share the altruist's genes (the theory is treated fully in Chapter 5). But in his late work, beginning around 2010, Wilson turned against kin selection, mounting a direct challenge to the theory he had long championed and arguing that it was inadequate to explain the origin of eusociality. In its place he advanced multilevel selection — the idea that natural selection acts simultaneously at more than one level, on individuals within groups and on groups within populations — as the true explanation of how altruism and eusociality arise. This was a startling public reversal by one of the theory's most famous proponents, and it set the stage for one of the most acrimonious scientific disputes of the era.
The logic of multilevel selection, as Wilson deployed it, turns on a permanent tension between two levels of natural selection pulling in opposite directions. At the level of the individual within a group, selection favors selfishness: the individual who takes more and gives less out-reproduces its more generous neighbors. But at the level of the group competing against other groups, selection favors altruism: the group whose members cooperate and sacrifice for one another out-competes and outlasts the group of selfish individuals. Groups containing altruists, Wilson argued, prevail over groups without them, so that altruism can spread through group-level selection even as it is disfavored within each group. The two forces are perpetually in conflict, and it is this unresolved tension between individual and group selection, in Wilson's view, that shapes all social life. He captured the individual-level danger with a vivid analogy: selfish defection within a cooperative whole is like cancer, in which cells reproduce for their own benefit at the expense of the organism they compose. Society, like the body, is perpetually threatened from within by the selfish interests of its own members, and held together only by the countervailing force of selection among groups.
Wilson was careful to situate full eusociality within a broader spectrum of cooperation, for advanced sociality did not spring up from nothing but emerged from a long prior history of cooperative living. Cooperation pervades biological systems from the bacteria upward, he emphasized, long predating the advanced societies that represent its pinnacle, and the living world displays a whole range of grades of social organization, from loose aggregations through intermediate stages to the tightly integrated eusocial colony. The mechanisms that foster cooperation are correspondingly various — kin selection among relatives, direct reciprocity between partners who exchange favors, and the group-level selection Wilson came to emphasize — and these mechanisms are not necessarily exclusive but may operate together. Wilson's late position was not that kin selection plays no role whatever, but that it is insufficient by itself to explain the origin of eusociality, and that group selection must be added to the account. The picture he painted was of cooperation as a deep and pervasive feature of life, arising by multiple mechanisms and reaching, in a few rare lineages, the extraordinary heights of full eusociality.
One biological detail played a quiet but crucial role in Wilson's account of how societies assemble themselves: phenotypic plasticity, the capacity of a single genome to produce different forms and behaviors depending on circumstance. The sterile worker and the fertile queen of an ant colony are often genetically identical, their dramatic differences a product not of different genes but of different developmental pathways switched on by environment and circumstance. This plasticity, Wilson emphasized, is what makes the division of labor possible: a single genome can encode an entire society, producing the whole range of castes and behaviors that a functioning colony requires. The colony is not a collection of genetically specialized types but the expression, in many bodies, of a single flexible genetic program, deployed differently in different individuals according to the colony's needs. This insight connected the origin of societies to the deeper biology of development, showing how the raw material for social complexity lay latent in the plasticity of the individual organism, waiting to be organized by the selective pressures that the crossing of the eusocial threshold unleashed.
Wilson's challenge to kin selection did not go unopposed; on the contrary, it provoked a scientific controversy of remarkable intensity. When Wilson, together with the mathematical biologists Martin Nowak and Corina Tarnita, published a 2010 paper attacking the foundations of inclusive-fitness theory, the response from the community of evolutionary biologists was swift and overwhelmingly hostile: well over a hundred scientists signed a rebuttal defending kin selection, and many of Wilson's longtime colleagues regarded his new position as simply mistaken. Wilson acknowledged the intensity of the opposition — that his position remained contested, that many biologists rejected it — but he did not retreat, insisting to the end of his life that multilevel selection offered a better account of the origin of eusociality than the kin-selection orthodoxy. The dispute was painful and personal, pitting Wilson against scientists who had built on his own earlier work, and it remains unresolved; the majority of evolutionary biologists continue to favor inclusive-fitness theory, while Wilson's camp maintains that group selection has been unjustly neglected. This chapter does not attempt to adjudicate the quarrel, which turns on technical questions of evolutionary modeling, but presents it as the genuine and ongoing scientific dispute it is.
When Wilson turned from the insects to humanity, he applied the same framework, and reached conclusions no less provocative. Human beings, he argued, are a fundamentally social — indeed, in a meaningful sense, a eusocial — species, whose ecological dominance, like that of the ants, rests on advanced cooperation. The human breakthrough he traced through a series of prehuman steps: the descent of ancestral apes to the ground, the freeing of the hands, the use of tools, the growth of the brain, and above all the control of fire and the establishment of defensible campsites. The campsite, Wilson proposed, played for human evolution the role that the nest plays for insects — a defensible, provisioned home base around which intense cooperation could develop, the human equivalent of the crucible of eusociality. He argued, strikingly, that social bonding, more than tool use, was the key driver of the evolution of human intelligence: the demands of living in complex cooperative groups, of tracking allies and rivals and obligations, drove the expansion of the human brain. Humanity's conquest of the Earth, like the insects', was in this account a social achievement, made possible by the same deep evolutionary logic of cooperation.
The decisive human innovation, layered atop this social foundation, was language. Wilson examined the origin of language as the breakthrough that enabled human culture and cooperation to reach their extraordinary heights — the capacity to share detailed information, to coordinate complex collective action, to transmit knowledge across generations, and to construct the shared imagined worlds of myth, religion, and art. With language, human culture could evolve, accumulating innovations over generations in a way no other species could match, made possible by the large brain and the capacity for symbolic thought. Wilson understood this cultural evolution as coupled to biological evolution through gene-culture coevolution, in which biological and cultural inheritance shape each other across the generations (the mechanism is treated in Chapter 14). Human nature and human culture, on this view, cannot be understood apart, for culture is the product of a mind built by evolution, and the mind is in turn reshaped by the cultural environments it creates. The cultural variation that distinguishes human societies from one another is real and vast, but it is patterned, Wilson argued, by the underlying regularities of an evolved human nature common to all.
From the multilevel-selection framework Wilson derived his central and haunting image of human nature: humanity as an evolutionary chimera, a creature permanently torn between two opposed sets of impulses. Because human beings are shaped by selection at both the individual and the group level, Wilson argued, we are built with contradictory drives: individual selection has made us selfish, competitive, and self-serving, while group selection has made us altruistic, cooperative, and capable of virtue. We are neither wholly good nor wholly evil but irreducibly both, a mixture of saint and sinner written into us by the two levels of selection that shaped our ancestors. This inner conflict, Wilson maintained, is not a flaw to be corrected but the permanent condition of human nature, the source of both our noblest aspirations and our darkest tendencies. Individual selection favors the sins — selfishness, greed, cowardice — while group selection favors the virtues — courage, generosity, loyalty — and human moral life is the ceaseless struggle between them. In this image Wilson found a biological account of the age-old religious intuition that human beings are divided against themselves, at war within their own natures.
From this conflicted human nature, Wilson argued, flow the great institutions of human culture, each an expression of our evolved social instincts. Morality, he proposed, originates not in divine command but in the evolved social instincts produced by multilevel selection — the moral sense a biological adaptation, arising from the tension between our selfish and our altruistic dispositions. Religion he analyzed as a product of evolution, arising from the human predispositions toward group belonging, obedience, and the search for meaning, and serving above all the function of binding groups together — while, in the same motion, dividing them from outsiders, for the tribal instinct that unites the in-group also sets it against the out-group. The creative arts, too, he traced to evolved human nature, to the mind's capacity for language, metaphor, and the sharing of imagined worlds. And underlying all of them was tribalism, the deep human tendency to form groups and favor one's own, which Wilson regarded as among the most powerful and most dangerous of human instincts — the root of loyalty and solidarity, but also of xenophobia, war, and the endless conflict between human groups (these themes connect to the treatment of human nature in Chapter 16 and of religion in Chapter 23).
Wilson was unsparing about the dangers this evolutionary inheritance poses in the modern world. The tribal instincts that served our ancestors well in the competition between small groups have become, in an age of global interconnection and terrible weapons, a source of grave peril, driving the wars, hatreds, and divisions that scar human history and threaten human survival. He captured the predicament in a memorable and mordant image: humanity, he wrote, has created a Star Wars civilization, with Stone Age emotions, medieval institutions, and godlike technology — a species whose technological power has raced far ahead of the ancient emotional constitution that still governs its behavior. This mismatch between our evolved nature and our created circumstances Wilson regarded as the central danger of the human condition, the source of our tendency to turn our godlike powers to tribal and destructive ends. Yet he did not counsel despair. The same self-understanding that reveals the danger, he believed, also offers the means of managing it: a species that comprehends the evolutionary roots of its own tribalism and aggression is, for the first time, in a position to rise above them, to use its reason to check the ancient instincts that reason has at last laid bare.
Wilson marveled at the speed of humanity's ascent once the essential innovations were in place. From small bands of hunter-gatherers, the human species had sprinted, in a few tens of thousands of years — a geological eyeblink — to villages, agriculture, cities, and finally the global technological civilization of the present, a rate of change without precedent in the history of life. This sprint to civilization was made possible by culture and cooperation, by the capacity to accumulate and transmit innovations that biological evolution alone could never have matched. But it had also outrun our biological evolution entirely, leaving us with the emotional and instinctual constitution of Paleolithic hunter-gatherers in a world transformed beyond recognition. Turning at last to Gauguin's final question — where are we going? — Wilson considered humanity's future in the light of its evolved and conflicted nature. He offered no confident prophecy, but he insisted that the answer depended on whether our species could achieve the self-understanding needed to govern its ancient instincts wisely, and could summon the will to preserve the living world from which it had sprung and on which it still depended.
Underlying Wilson's willingness to reduce the great questions to biology was a conviction he stated with characteristic boldness: that the religious creeds and philosophical mysteries by which humanity has always sought to understand itself could, in the end, be traced to genetic and evolutionary origins. The deepest questions of human existence — what we are, what created us — were, for Wilson, at bottom biological questions, answerable through the evolutionary study of our species and its social relatives rather than through revelation or metaphysics. This was a hard saying, and Wilson knew it would offend those who held such questions to lie forever beyond the reach of science. But it followed directly from the naturalism that had guided his entire career: the conviction that human beings are wholly a part of nature, that their minds and cultures and moral intuitions are products of evolution, and that the same methods which had illuminated the origin of the ant colony could illuminate the origin of the human soul. Genesis, his final book, was the distilled expression of this faith — an old scientist's last testament to the power of evolutionary biology to answer the questions that matter most.
Wilson's late synthesis was, in the end, a characteristically audacious attempt to answer the largest questions with the tools of evolutionary biology. He believed that the deep evolutionary story of social behavior — the story of the major transitions, of the rare crossing into eusociality, of the tension between individual and group selection — was, in the main, all that is needed to understand where societies come from and what human beings fundamentally are. Where religion offered myth and philosophy offered speculation, Wilson offered a naturalistic account grounded in the comparative study of social species, insisting that the only way to fully understand human behavior is to study its evolutionary history alongside that of the other social animals. Genesis, his final statement, framed this as a short, bold synthesis rather than an exhaustive treatise — a distillation, at the end of a long life, of his deepest convictions about the origin and nature of society. Whether or not his controversial embrace of group selection ultimately prevails, the questions he pressed and the framework he built represent the culmination of a lifetime's thought about the deepest of all biological problems: how, out of the struggle of individuals, the cooperation that makes societies possible ever came to be.
The Social Conquest of Earth and Genesis stand as the summation of Wilson's lifelong effort to understand social life, from the ant colonies of his boyhood to the human species itself. In them he drew together the threads of his entire career — the study of the social insects, the puzzle of altruism, the biology of human nature, the vision of consilience — into a single grand narrative of how cooperation conquered the Earth, twice, in the insects and in ourselves. That the narrative rested on a contested theory of selection does not diminish its ambition or its coherence; Wilson was staking out, in the boldest terms, a position on the deepest question in the science of social behavior, and he did so with the same synthesizing daring that had marked his work from the first. Whatever the ultimate verdict of evolutionary biology on group selection, Wilson's late books pose the right questions with unmatched clarity and force, and they leave us with an image of humanity — the conflicted, tribal, godlike, endangered evolutionary chimera — that is as challenging as it is unforgettable. In them, the boy who had watched the ants and wondered how their societies could exist arrived, at the end of his life, at his fullest answer to that ancient question, and at its application to the strangest social species of all: our own.