The Insect Societies

Ecological dominance. Wilson opens by establishing that social insects, though comprising only a small fraction of all insect species, dominate terrestrial ecosystems in sheer biomass and ecological impact. Their staggering abundance and their tight organization make them, in his framing, among the most consequential animals on Earth, and therefore a subject fully worthy of the comprehensive synthesis the book undertakes. [QL496.7]

Defining eusociality. The chapter sets out the defining criteria of true sociality—cooperative brood care, overlapping generations within a colony, and a reproductive division of labor. These features together distinguish the highly social insects from merely gregarious or aggregating species, and they frame precisely the phenomena that the remainder of the book will describe, compare across groups, and ultimately try to explain. [QL496]

Convergent evolution of sociality. Wilson notes that advanced sociality has arisen independently in the ants, the termites, and various lineages of bees and wasps. This repeated, convergent origin across unrelated groups strongly implies common selective pressures at work, and it invites a general evolutionary theory of social behavior rather than a series of disconnected, group-specific natural-history accounts. [QH366.2]

Scope of the synthesis. The chapter announces the book's central ambition: to gather the scattered findings of many specialists across many taxa into a single unified science of insect societies. Wilson explicitly positions the work as consolidating a fragmented field and providing a durable foundation for the comparative study of social evolution that he hopes will follow from it. [QL496]

Colony as a unit. Wilson introduces the powerful idea that a colony can be analyzed as an organized whole possessing emergent properties, not merely as a loose collection of individual insects. This organismal perspective recurs throughout the book, shaping how he treats caste, communication, and reproduction, and it anticipates the explicit superorganism concept he would develop decades later with Hölldobler. [QL496]

The central puzzle of altruism. The chapter foregrounds the deep evolutionary paradox of sterile workers that sacrifice their own reproduction for the good of the colony, previewing kin selection as the eventual resolution. By framing altruism as the single most important problem the book must solve, Wilson gives the entire synthesis a clear theoretical spine and a unifying question. [QL775]

Human fascination and analogy. Wilson reflects on humanity's long fascination with insect societies and cautions firmly against naive analogies between insect colonies and human social orders. While acknowledging why such comparisons perennially tempt observers, he insists on rigorous, evolutionarily grounded biology over facile metaphor, a methodological stance that governs how he handles even his most sweeping generalizations. [QL496]

A comparative program. The chapter argues that systematically comparing the four great groups of social insects will reveal both shared underlying principles and instructive, revealing differences among them. This comparative method underlies the whole synthesis and its central search for general laws of social evolution, treating each group as one natural experiment in the recurring evolution of cooperation. [QL496]

Ant diversity. Wilson surveys the extraordinary range of ant species, body forms, and ways of life, establishing ants as the most diverse and ecologically pervasive of all the social insects. Their remarkable variety supplies much of the empirical richness on which the rest of the book draws, and it reflects the group Wilson himself knew more intimately than any other. [QL568.F7]

Colony organization. The chapter describes the basic architecture of an ant colony—queen, sterile workers, and developing brood—and the division of labor that sustains it. This organizational template serves as a recurring reference point throughout the book, against which Wilson repeatedly compares the differing social arrangements found among the bees, the wasps, and the termites. [QL568.F7]

Nesting and habitats. Ants occupy an enormous variety of nests and environments, from soil and rotting wood to elaborate arboreal and highly specialized structures. The chapter links this diversity of nesting ecology directly to colony function and to the specific selective pressures shaping social traits, showing how where ants live shapes how their societies are organized. [QL568.F7]

Life cycle. Wilson traces the ant colony's life cycle from its founding by a single mated queen, through a phase of growth driven by worker production, to eventual reproduction via winged males and future queens. This colony life cycle frames the later discussions of caste determination and population dynamics, grounding those analyses in the concrete developmental history of a colony. [QL568.F7]

Foraging and trophic roles. The chapter examines the many ways ants exploit food, acting as predators, scavengers, seed harvesters, and tenders of honeydew-producing insects. These diverse trophic roles go far toward explaining ants' ecological dominance, since collectively they move enormous quantities of energy and material through the terrestrial ecosystems in which ants are so abundant. [QL496.7]

Communication overview. Ants coordinate their collective activity chiefly through chemical signals, a defining feature that Wilson introduces here and reserves for fuller, more systematic treatment in a later dedicated chapter. Chemical communication is presented from the outset as absolutely central to colony integration, the invisible medium through which thousands of individuals act as a coordinated whole. [QL496.5]

Taxonomic and evolutionary context. Wilson situates ants phylogenetically among the Hymenoptera and sketches their evolutionary origin from wasp-like ancestors many millions of years ago. This grounding connects ant sociality firmly to the broader evolution of the order, and it reminds the reader that the ants' elaborate societies represent one particular, spectacularly successful outcome of a much wider evolutionary story. [QL568.F7]

Ants as a model system. The chapter argues that ants, given both Wilson's own deep expertise and their sheer diversity, serve as the book's principal exemplar of insect sociality. Their detailed study anchors many of the general claims the book advances about the mechanisms and evolution of social behavior, functioning as the empirical touchstone against which broader theories are tested. [QL568.F7]

Grades of bee sociality. Wilson emphasizes that bees display a complete spectrum of social organization, from wholly solitary species through communal forms to the highly social, which makes them ideal for studying the very origins of sociality. This graded series lets him infer plausible evolutionary pathways that remain hidden in fully social groups where only the endpoint survives to be observed. [QL568.A6]

The honeybee colony. The chapter details the intricately organized honeybee society, with its single reproductive queen, its sterile female workers, and its sophisticated behavioral coordination. Honeybees supply some of the clearest and best-studied examples of advanced insect social behavior anywhere, and they recur throughout the book as a benchmark for what a fully elaborated insect society can achieve. [QL568.A6]

Bumblebees and intermediate forms. Bumblebees, with their smaller and typically annual colonies, illustrate an instructive intermediate grade of sociality between the solitary bees and the honeybees. Comparing them with the far larger and perennial honeybee societies highlights how colony size, longevity, and permanence relate to the degree of social complexity a group achieves over evolutionary time. [QL568.A6]

The dance language. Wilson discusses the celebrated honeybee waggle dance as a remarkable symbolic communication system that conveys both the distance and the direction of a food source to nestmates. It stands among the most sophisticated communication systems known outside of humans, and Wilson treats it as a striking demonstration of how far insect signaling can be elaborated. [QL496.5]

Caste determination in bees. The chapter examines how nutrition and developmental environment channel genetically similar female larvae into either queen or worker roles. This developmental plasticity connects the biology of individual development directly to the colony's division of labor, showing that caste in bees is an environmentally regulated outcome rather than a rigidly predetermined genetic fate. [QL495]

Origins of worker altruism. Wilson applies careful evolutionary reasoning to the sterility of bee workers, invoking both their genetic relatedness to the queen and the reproductive advantages that accrue to the colony as a whole. Bees thereby furnish key evidence in the book's broader argument about how altruistic, self-sacrificing behavior can evolve and be maintained by natural selection. [QL775]

Solitary-to-social transitions. Using the striking diversity of bee lifeways, the chapter reconstructs plausible incremental steps leading from solitary nesting through communal arrangements to full eusociality. This inferred evolutionary sequence illuminates how sociality can arise gradually, one modest behavioral change at a time, rather than appearing suddenly and inexplicably as a fully formed social system. [QH366.2]

Ecological importance of bees. The chapter notes the pivotal ecological role bees play as pollinators of flowering plants, tying their social biology to wider consequences for whole ecosystems. This connection links the internal organization of bee societies to their outsized external importance, reinforcing Wilson's recurring theme that small social insects have effects far out of proportion to their size. [QK926]

Wasp sociality. Wilson describes the social wasps as yet another independent origin of advanced insect society, offering valuable comparative leverage on the general problem of social evolution. Their colonies and nests parallel yet differ from those of bees and ants in instructive ways, and these systematic differences help Wilson separate the essential features of sociality from the merely incidental. [QL568.V5]

Nest architecture. The chapter examines the intricate paper nests that social wasps construct, whose form reflects both the organization of the colony and its needs for defense and brood-rearing. Nest architecture becomes, in Wilson's hands, a revealing window onto collective behavior and coordination, since the built structure records the combined activity of many cooperating individuals. [QL568.V5]

Dominance hierarchies. Among many social wasps, reproductive roles are settled not by fixed morphological castes but through ongoing dominance interactions among adult females. This behavioral mechanism reveals an alternative evolutionary route to reproductive division of labor, one based on contest and social rank rather than on the irreversible developmental commitment seen in more advanced insect societies. [QL496]

Founding strategies. Wilson contrasts wasp colonies founded by a single queen with those begun cooperatively by groups of females, carefully analyzing the costs and benefits of each strategy. Founding mode strongly shapes early colony dynamics and the potential for reproductive conflict, and it provides another axis along which the diverse social wasps can be compared and understood. [QL568.V5]

Caste flexibility. In many wasps, castes are behaviorally rather than morphologically distinct, so individuals can shift roles depending on circumstances and colony needs. This flexibility illuminates the likely evolutionary precursors of the rigid, physically differentiated caste systems found in ants and termites, capturing an earlier and more plastic stage in the elaboration of insect division of labor. [QL496]

Aggression and reproductive conflict. The chapter explores the often intense competition among potential reproductives within wasp colonies, exposing the fundamental tension between cooperation and individual self-interest that runs through all social evolution. This visible conflict in wasps foreshadows Wilson's broader recognition that colonies are arenas of both harmony and struggle rather than perfectly integrated wholes. [QL496]

Comparative insights. By comparing wasps with bees and ants, Wilson works to isolate the general principles of sociality from the group-specific idiosyncrasies of any one lineage. The wasps' partial and highly variable sociality proves especially revealing of transitional evolutionary states, offering glimpses of intermediate arrangements that more fully social groups have long since left behind. [QL496]

Evolutionary transitions in wasps. The chapter uses the diversity of wasp social organization to trace probable pathways from solitary through incipiently social to fully social living. This reinforces the book's overarching theme that sociality evolves through a series of intelligible, incremental steps, each individually advantageous, rather than emerging all at once as an improbable and unexplained leap. [QH366.2]

An independent origin. Wilson highlights the termites as the one major group of social insects that arose entirely outside the Hymenoptera, evolving their sociality separately among the cockroach-related insects. Their independence provides a crucial test of which features of insect sociality are truly universal and which are peculiar to the ants, bees, and wasps that dominate the rest of the book. [QL529]

Different genetics of altruism. Because termites are ordinary diploids, with both males and females serving as sterile workers, their sociality cannot rest on the peculiar haplodiploid relatedness so often invoked to explain the Hymenoptera. This difference forces a search for broader explanations of altruism and thereby enriches the book's whole theory of social evolution beyond any single genetic mechanism. [QH455]

Caste systems. The chapter details the elaborate termite caste system—workers, soldiers, and reproductives—and the developmental pathways that produce each type from similar starting material. This polymorphism rivals in complexity anything found among the ants, and it demands the same kind of evolutionary and developmental explanation that Wilson applies to caste throughout the book. [QL529]

Symbiosis and digestion. Termites depend on gut-dwelling microbial symbionts to digest the cellulose in wood, a mutualism that lies at the very foundation of their ecology and success. Wilson links this remarkable nutritional biology directly to the termites' ecological importance and abundance, illustrating how an internal partnership with microbes underwrites an entire lineage's social and ecological achievements. [QL496.4]

Nest construction. Termite mounds and nests rank among the most impressive structures built by any animals, embodying collective construction and sophisticated regulation of the internal environment. The chapter treats these edifices as products of coordinated social behavior, showing how the combined labor of countless individuals, each following simple rules, yields architecture of remarkable scale and functional sophistication. [QL529]

Soldier defense. Specialized soldier castes, often equipped with bizarre and highly modified defensive morphologies, illustrate division of labor carried to an extreme within termite societies. Their sterility and readiness for self-sacrifice pose the central problem of altruism in yet another distinct form, one that Wilson uses to press the general question of how such costly cooperation evolves. [QL529]

Colony founding by royal pairs. Unlike the Hymenoptera, termite colonies are founded by a long-lived king and queen pair that reproduce together over many years, fundamentally altering the colony's reproductive dynamics. The chapter analyzes how this distinctive founding arrangement shapes colony structure, genetic relatedness, and lineage, distinguishing termite societies in important ways from those of the social Hymenoptera. [QL529]

Convergence with ants. Wilson stresses the striking convergence between termites and ants—in caste, nest-building, and ecological role—despite their entirely separate evolutionary origins. He argues that similar ecological pressures have repeatedly produced strikingly similar social solutions, a key comparative lesson that supports the book's search for general, cross-cutting laws governing the evolution of insect societies. [QH366.2]

The essence of sociality. Wilson identifies the division of labor, both reproductive and behavioral, as the single defining achievement of insect societies and the source of their success. How a colony partitions its many tasks among specialized members becomes the chapter's central analytical problem, and Wilson treats it as the key to understanding what makes an insect society more than a mere aggregation. [QL496]

Morphological castes. The chapter examines physically distinct castes—soldiers, majors, and minors—and analyzes how their differing body forms suit them to particular colony functions. Morphological specialization is treated as an evolved efficiency of colony labor, a way of matching workers to tasks that increases the colony's overall productivity and, ultimately, its reproductive success as a unit. [QL494.5]

Temporal castes. Wilson describes age polyethism, the widespread pattern in which individual workers shift through a sequence of tasks as they age, typically moving from nursing brood inside the nest to foraging outside it. This temporal division of labor allocates work efficiently without requiring physically distinct body forms, achieving specialization through behavioral change over an individual's lifetime. [QL496]

Caste determination. The chapter analyzes how nutrition, hormones, and environmental cues channel developing larvae into different castes, integrating developmental biology directly with social organization. Caste is shown to be a flexible, actively regulated outcome rather than a fixed genetic destiny, so that colonies can adjust the kinds of individuals they produce in response to their changing needs. [QL495]

Ergonomics of the colony. Wilson introduces an explicitly ergonomic view of the colony, treating it as a system that optimizes the allocation of its workers among competing tasks to maximize overall productivity. This economic framing, unusual for its time, anticipates the later optimization and cost-benefit models of social insect biology and reflects Wilson's drive to make the field quantitative and predictive. [QL496]

Flexibility and response. Colonies continually adjust the proportions of workers performing various tasks in response to changing needs, disturbances, and opportunities. This adaptive plasticity reveals a decentralized system of workforce regulation, in which colony-level responsiveness emerges from the collective behavior of many individuals rather than from any central controller directing the allocation of labor from above. [QL496]

Efficiency and specialization. The chapter carefully weighs the productivity benefits of specialization against its costs in reduced flexibility, exploring why colonies typically balance dedicated specialist castes with more versatile generalist workers. This trade-off between efficiency and adaptability recurs across social insect groups and helps explain the particular mix of caste rigidity and flexibility each species has evolved. [QL496]

Evolution of complex castes. Wilson considers how selection acting at the level of the whole colony elaborates caste systems over evolutionary time, favoring arrangements that enhance colony survival and reproduction. This links the division of labor directly to the reproductive success of the colony as a unit, reinforcing the organismal, colony-centered perspective that runs throughout the entire book. [QH366.2]

Pheromones as language. Wilson presents chemical signals as the primary medium of communication in insect societies, arguing that pheromones effectively function as a chemical language that integrates and coordinates all colony activity. This chapter systematizes what was then an emerging field, assembling scattered findings into a coherent framework for understanding how thousands of insects act together as one. [QL496.5]

Classification of pheromones. He classifies pheromones by their function—alarm, recruitment, recognition, and trail-marking among them—providing a durable and widely adopted framework for analyzing chemical communication. This functional taxonomy of signals gave researchers a common vocabulary and a systematic way to organize the bewildering diversity of chemical messages that pass constantly among the members of an insect colony. [QL496.5]

Trail pheromones. The chapter details how ants lay chemical trails to guide their nestmates to food sources, enabling the mass recruitment that makes ant foraging so effective. Trail communication exemplifies how a very simple signal, deposited and followed by individuals, can generate complex, adaptive collective foraging behavior at the level of the whole colony without any central coordination. [QL496.5]

Alarm and defense signals. Alarm pheromones rapidly mobilize colony defense, spreading quickly through the nest to summon and orient defenders toward a threat. The chapter shows how such volatile, fast-acting chemical signals coordinate urgent collective responses, their physical properties—rapid diffusion and quick decay—being well matched to the demands of the defensive function they serve within the colony. [QL496.5]

Recognition systems. Colony-specific chemical labels allow insects to distinguish their own nestmates from intruders, underpinning both colony integrity and defense against parasites and social parasites. Recognition is shown to be fundamental to social cohesion, since a colony can only function as a cooperative unit if its members can reliably tell friend from foe at the level of individual encounters. [QL496.5]

Multimodal communication. Beyond chemical signals, Wilson discusses the tactile, acoustic, and vibrational channels that supplement pheromonal communication in many social insects. Communication is portrayed as an integrated, multichannel system in which different modalities carry different kinds of information, together enabling the rich coordination that colony life requires across varied contexts and over both short and long distances. [QL496.5]

Information and mass action. The chapter explores how individually simple signals aggregate through mass action into colony-level information processing, producing adaptive collective behavior without any central decision-maker. This early articulation of distributed coordination anticipates modern ideas about self-organization and collective intelligence, framing the colony as a system that computes solutions through the summed simple actions of its members. [QL496]

Evolution of signals. Wilson considers how communication systems themselves evolve, tending to become more elaborate as colonies grow larger and more socially complex. Signal evolution is tied directly to the escalating coordination demands of large societies, so that the sophistication of a species' chemical and other communication reflects the organizational challenges its particular way of life imposes. [QL496.5]

The colony as a population. Wilson analyzes colony growth, maturation, and reproduction using the tools of population biology, treating the colony's demographic trajectory as central to understanding its evolutionary success. This deliberately quantitative approach distinguishes the synthesis from earlier natural-history accounts and reflects Wilson's conviction that social insects can be studied with the same rigor as any other population. [QL752]

Founding and early growth. The chapter examines the highly vulnerable founding stage, when a lone queen must survive and produce her first workers, and the exponential growth that follows once a worker force is established. These early dynamics strongly influence whether a colony survives at all, making the founding period a critical bottleneck in the colony life cycle. [QL496]

Colony size and complexity. Larger colonies tend to exhibit more elaborate caste systems and more sophisticated coordination than small ones, linking demography directly to social complexity. Wilson explores this scaling relationship across species, showing that as colonies grow in size they typically also grow in organizational intricacy, so that size and social elaboration tend to evolve together. [QL496]

Reproductive investment. Mature colonies shift their resources from further growth toward producing winged reproductive males and future queens, timing this investment to maximize the chances of successful dispersal and colony founding. The chapter analyzes this fundamental trade-off between continued colony growth and current reproduction, a decision that shapes the whole life history of the social insect colony. [QL496]

Life history strategies. Wilson compares the differing schedules of growth and reproduction across species, relating them to ecology, competition, and environmental predictability. Colony life history thereby becomes another axis of comparative analysis, allowing the many social insects to be arrayed and understood according to how they allocate effort between building the colony and producing the next generation of colonies. [QL752]

Density and regulation. The chapter considers how competition and limited resources regulate both colony size and the density of colonies in a population, connecting social insects to general ecological principles of population control. This integration situates colony dynamics within the broader framework of population ecology, treating colonies as units subject to the same regulatory forces as individual organisms. [QL752]

Colony mortality. Colonies, much like individual organisms, face characteristic risks and have characteristic lifespans, and Wilson examines the causes of colony death along with their evolutionary implications. Patterns of colony mortality shape the selection pressures acting on colony traits, since features that improve a colony's chances of surviving to reproduce will be favored over evolutionary time. [QL752]

Superorganism demography. By treating the colony as a reproductive unit that is born, grows, matures, and dies, Wilson frames its demography in explicitly organismal terms. This reinforces the superorganism analogy that runs quietly through the book and would later become explicit, casting the colony's life cycle as directly comparable to the life cycle of a single multicellular organism. [QL496]

The social environment as habitat. Wilson observes that colonies create rich, stable, resource-filled environments that many other organisms have evolved to exploit, making insect societies major hubs of symbiosis. This ecological insight opens a wide-ranging survey of the interspecies relationships that cluster around colonies, revealing the nest not as a sealed fortress but as a bustling habitat teeming with guests, partners, and parasites. [QL496.4]

Myrmecophiles and termitophiles. The chapter catalogs the astonishing diversity of guests—beetles, mites, and countless other arthropods—that live within ant and termite nests, often chemically disguised to escape detection. These intimate associations reveal the surprising permeability of colony boundaries, showing that even the well-defended societies of social insects are routinely penetrated and inhabited by specialized outsiders exploiting their resources. [QL496.4]

Social parasitism. Wilson analyzes ants that parasitize the colonies of other ants, ranging from temporary parasites that need a host only to found a colony, to permanent inquilines that live wholly within a host society. Social parasitism represents a striking evolutionary exploitation of sociality itself, in which one species hijacks the cooperative labor that another has evolved. [QL496.4]

Slave-making ants. The chapter examines dulotic, or slave-making, ants that raid the colonies of other species to capture brood, which then mature and labor for the raiders. This dramatic form of interspecies exploitation involves intricate behavioral adaptations on the part of the raiders, and Wilson treats it as a vivid illustration of how far the exploitation of social insects can be carried. [QL568.F7]

Chemical deception. Many symbionts and social parasites penetrate colonies by mimicking or actively acquiring their hosts' chemical recognition cues, thereby defeating the colony's chemical defenses. This chemical deception illustrates an ongoing coevolutionary arms race between colonies and the intruders that exploit them, with recognition systems and the means of subverting them continually escalating against one another over evolutionary time. [QL496.4]

Mutualisms. Not all of the associations Wilson surveys are exploitative; the chapter also discusses genuine mutualisms, such as ants tending honeydew-producing insects in exchange for food and protection, that benefit both partners. These mutualistic partnerships broaden the ecological reach of colonies, embedding them in webs of cooperation with other species alongside the many parasitic relationships they also sustain. [QL496.4]

Coevolutionary dynamics. The chapter frames host–symbiont relationships as coevolving systems, in which the defenses of colonies and the counter-adaptations of their exploiters escalate against one another over long stretches of evolutionary time. Social insects thus act as powerful selective forces driving evolution in many associated lineages, shaping the traits of the guests, parasites, and partners that depend upon them. [QH366.2]

Evolution of parasitic strategies. Wilson traces how social parasitism may evolve gradually from ancestral free-living habits or from facultative associations with other colonies, linking the most extreme specialized exploiters back to their less specialized relatives. This evolutionary reconstruction renders even the strangest parasitic strategies intelligible as endpoints of comprehensible sequences rather than as inexplicable oddities of nature. [QH366.2]

Kin selection. Wilson presents Hamilton's theory of kin selection as the central explanation for altruism in insect societies: by helping close relatives to reproduce, a sterile individual propagates copies of its own genes indirectly. This theory resolves the long-standing paradox of sterile workers and anchors the book's whole evolutionary argument, supplying the mechanism that makes self-sacrificing cooperation Darwinian rather than mysterious. [QL775]

Haplodiploidy and relatedness. The chapter explains how the unusual haplodiploid genetics of the Hymenoptera can make sisters more closely related to one another than to their own offspring, strongly favoring the evolution of sterile worker sisterhoods. This mechanism helps account for the striking fact that advanced sociality has arisen repeatedly within the Hymenoptera, connecting a genetic peculiarity to a major evolutionary pattern. [QH455]

Inclusive fitness. Wilson articulates the concept of inclusive fitness—an individual's own reproduction plus its effects on the reproduction of its relatives, each weighted by relatedness—as the quantity that natural selection actually maximizes. This reframing accommodates altruistic behavior comfortably within Darwinian theory, showing that helping relatives can be favored by selection whenever the genetic benefits sufficiently outweigh the costs. [QH375]

The termite exception. Because termites lack haplodiploidy, the chapter candidly acknowledges that relatedness alone cannot explain their equally advanced sociality, prompting Wilson to appeal to ecological factors, inbreeding, and other considerations. This tension enriches rather than undermines the genetic theory, forcing recognition that kin selection, while powerful, operates alongside other forces in the evolution of insect societies. [QL529]

Conflict within colonies. Wilson notes that the genetic interests of colony members are shared only imperfectly, so that genetic conflict over reproduction can and does arise even within highly cooperative colonies. Recognizing this potential for conflict alongside cooperation foreshadows later work on reproductive disputes within colonies and tempers any picture of the colony as a perfectly harmonious and conflict-free unit. [QL775]

Levels of selection. The chapter weighs selection acting on individuals against selection acting on whole colonies, an issue Wilson would return to and substantially revise across his long career. He grapples here with how colony-level advantage relates to gene-level accounting, an unresolved tension that would eventually lead him, decades later, toward a controversial re-embrace of group selection. [QH375]

Predictions and tests. Kin selection yields specific, testable predictions about worker behavior and especially about the sex ratios colonies should produce, and the chapter surveys the entomological evidence bearing on them. This linkage of abstract theory to concrete, measurable observations exemplifies Wilson's insistence that the genetic theory of social behavior be empirically accountable rather than merely plausible. [QL775]

Toward a general theory. Wilson closes the book by proposing that the principles developed here for insects can be extended toward a much broader science of social behavior encompassing all animals. This concluding call is the explicit seed of the sociobiology synthesis he would publish just four years later, marking The Insect Societies as the launching point for his most ambitious project. [QL775]