Monogamy: The Social Technology That Built Civilization

Before we discard it as outdated, we must ask why it has endured for millennia.

There is a peculiar habit in modern society to reject out of hand anything seen as constraining rather than liberating our individual desires—especially if it is something we inherited from the past. A thing appears old—perhaps out of sync with contemporary values, an artifact of a less enlightened past—and so we assume it must be unnecessary, or worse, oppressive. We have no patience for antiquated customs, and even less tolerance for structures that impose obligations upon us. Monogamy, increasingly, is treated as one such relic—an outmoded framework that inhibits personal freedom rather than enhances it.

To be clear, monogamy is not under attack in the sense that governments are banning it or that individuals are consciously revolting against it. Rather, it is being abandoned, quietly but pervasively, in favor of something less rigid, less obligatory, and ultimately less defined. A growing cultural tendency treats lifelong, exclusive partnership as just one relationship model among many—perhaps useful for some, but hardly necessary.

Before we discard monogamy as an outdated constraint, we might do well to heed Chesterton’s Fence—the principle that before tearing down an old institution, we should first understand why it was built in the first place. Monogamy is not simply a personal choice, nor is it simply a religious sacrament—it is a civilizational technology. It has persisted not because it was forced upon humanity, but because it solved a fundamental problem in social organization: how to channel human relationships in a way that promotes stability, trust, and long-term investment in the future. It is, in effect, a structure that tempers our natural impulses in order to aim for something higher—something that makes the values we now take for granted possible.

We live in an age that prizes individual autonomy above all else, and that is a hard-won victory. But we must ask: what counterbalances that autonomy? What institutions remind us that we are part of something larger than ourselves? Historically, religion served that function, as did civic and communal obligations. But before those institutions could instill a sense of communal responsibility, we learned it first at the most personal, intimate level. Monogamous marriage was the first institution where individuals learned responsibility, trust, and the reciprocity required for society to function.

This, more than anything, was the animating force behind the same-sex marriage movement. The fight was not to tear down marriage but to be included within its structure—to gain access to its stabilizing rules and moral obligations. It was, at its core, a battle for recognition of the fact that monogamy and lifelong partnership are not simply heterosexual virtues but human ones. The argument that won the hearts and minds of the public was not about personal freedom or radical sexual autonomy; it was about commitment, responsibility, and belonging—about the necessity of stable, monogamous bonds as the foundation of a good and meaningful life.

And yet, a paradox has emerged. While marriage equality was won by affirming the civilizational importance of marriage, the culture at large is moving in the opposite direction. Instead of reinforcing the very obligations that made marriage a cause worth fighting for, we increasingly treat sex and relationships as purely transactional—as expressions of self-fulfillment rather than commitments to another person and, by extension, the community.

This shift is not merely a matter of private behavior; it has profound consequences for the way trust, social capital, and long-term responsibility are sustained. When sex is stripped of its moral and communal dimensions, when marriage is reduced to a flexible arrangement rather than a binding covenant, the social glue that holds communities together begins to erode. Hyper-individualism makes it harder—not easier—to sustain relationships, to build families, and to cultivate the kind of deep, lasting commitments that make societies flourish.

To dismiss monogamy as a mere preference—one among many possible relationship models—is to misunderstand its deeper significance. It is no coincidence that the societies that have built the most egalitarian, democratic, and high-trust institutions are overwhelmingly monogamous. Nor is it coincidence that societies that have struggled with instability, authoritarian rule, and concentrated wealth tend to have polygamous or kin-based marriage systems. This is not a moral indictment; it is a historical and sociological observation.

If we are to discard monogamy, we should at least be clear-eyed about what we are losing.

II. The Biology of Monogamy: Is Monogamy Natural or Unnatural? (It’s Both)

From an evolutionary perspective, strict lifelong monogamy is relatively rare in the animal kingdom. An often-cited statistic is that about 90% of bird species are socially monogamous, whereas at least 95–97% of mammalian species are polygamous or promiscuous in their mating patterns.¹ Humans, as mammals, do not fit neatly into the monogamous category by nature—our primate relatives like chimpanzees and gorillas are not monogamous, and the anthropological record shows that the majority of human societies have permitted polygamy. In the most comprehensive cross-cultural surveys, only around 15% of human societies strictly prescribe monogamy, while at least 85% have allowed men to take multiple wives (polygyny) under some conditions.²

Human evolutionary biology also provides mixed signals about our natural mating inclinations. Humans are characterized by a prolonged period of infant dependency and a high level of paternal investment in offspring relative to most mammals. Unlike our great-ape cousins, human males (in most societies) provide substantial care and provisioning for their children and mates. This suggests an evolutionary payoff to pair-bonding: if a man and woman formed a stable union, their offspring were more likely to survive in the challenging environments of human evolution. Anthropologist C. Owen Lovejoy famously hypothesized that the emergence of strong pair-bonds was a crucial step in human evolution that enabled our ancestors to cooperate and thrive in new niches.³

Humans might be best described as exhibiting facultative monogamy—capable of forming lasting monogamous bonds, especially when ecological or social conditions favor them, but also quite capable of polygamous or serially monogamous behavior under different conditions. Evolutionary psychologists note that human mating patterns are highly flexible and responsive to cultural norms.

Without cultural constraints, high-status males in many societies have historically taken multiple wives or concubines, maximizing their own reproductive success. This is evidenced not only by historical records but even by genetic data—studies of human DNA have found a greater variance in male reproductive success than female, indicating that, over millennia, some men fathered children with multiple women while many other men left few or no offspring.⁴ In other words, polygyny has been a recurrent pattern in human history, meaning that complete sexual equality in mating (one man for one woman) is not the automatic state of nature but rather an achieved state of society.

What, then, could drive the adoption of monogamy despite its apparent contradiction to the unfettered biological interests of powerful men? This question has been termed “the puzzle of monogamous marriage” by evolutionary scholars⁵.

Anthropologist Joseph Henrich points out that from a strictly Darwinian perspective, polygyny benefits successful males—so why would those very men (chiefs, kings, elites) ever agree to limit themselves to one wife? The answer proposed by Henrich’s research is that monogamous marriage norms spread because they conferred group-level advantages that ultimately benefited societies (and even the elites within them) in the long run.⁶

In essence, although individual male elites might gain short-term benefits from polygamy, a society full of unmarried, disenfranchised men and fractious polygamous households tends to experience more conflict and instability, which can threaten everyone’s prosperity and security. On the other hand, a society that institutionalizes monogamy reaps a range of social benefits: lower crime, less internal violence, more cooperative males, greater parental investment in children, and higher overall social trust.

Over time, these advantages could make monogamous societies more successful and cohesive, allowing them to out-compete or outlast more polygamous ones. This is a form of cultural group selection—that norms enforcing one-wife-per-man spread not because they maximized the reproductive output of top men (they didn’t), but because groups that embraced these norms fared better collectively.

From an evolutionary perspective, monogamy is best understood as a cultural innovation that channels human pair-bonding in ways that reduce competition, increase cooperation, and generally promotes social peace and stability. Monogamy does not come naturally to us, but we have evolved to become increasingly predisposed to it under the right conditions. Our psychology, in particular, has likely evolved to make us even more predisposed to monogamy as it confers group selection advantages.

III. Monogamy as “Civilizational Technology”

Looking back at the arc of human history, scholars have increasingly suggested that the advent of institutionalized monogamy was a turning point in the formation of large-scale civilizations. William Tucker, in Marriage and Civilization: How Monogamy Made Us Human, argues that the “pair-bonding of couples within the framework of a larger social group” was foundational for the emergence of complex society.⁷.-

In his view, human civilization was only possible once our ancestors adopted a social contract of sexual fidelity that quelled the disruptive rivalries of an unchecked mating free-for-all. Monogamy, in essence, is seen as a technology for social stability—a set of rules and expectations that allowed humans to shift from small, kin-based bands toward more cooperative, rule-governed societies of strangers.

It is useful to consider early human groups to grasp this concept. In small hunter-gatherer bands (the context of human life for tens of thousands of years), monogamy was common but not absolute—high-status males might take an extra wife if resources allowed, or serial monogamy (remarriage after death or divorce) occurred. However, on the whole, hunter-gatherers tended toward relatively egalitarian pair-bonding.

This is partly because in nomadic conditions, it is difficult for one man to provision multiple wives and their children. Anthropological studies show that foraging societies usually have low rates of polygyny—most men have one wife, and those that do have more typically have only two, not large harems.⁸

In contrast, when humans developed agriculture and herding (the Neolithic era and later), the dynamics shifted. With accumulated wealth (land, herds) came the ability and desire of successful men to acquire more wives. The archaeological and historical record from early agrarian civilizations (Mesopotamia, ancient China, etc.) indicates significant levels of polygamy among the elite classes. Tucker describes this as an interesting paradox: after millions of years of pair-bonding in hunter-gatherers, “polygamy makes a comeback at the dawn of civilization” once material surpluses permit it.⁹

In ancient agrarian empires, emperors and nobles often had numerous wives and concubines, while lower-status men struggled to find any wives at all. This inequitable distribution of mates sowed the seeds of social tension. The instability of polygamous societies eventually necessitated a new solution—a “male compromise,” as some evolutionary theorists call it, in which men collectively agree to monogamy in order to avoid constant violence and upheaval. In Tucker’s words,

“Civilizations are born when two people trust each other, namely a man and a woman. At this moment, we come out of the cold isolation of nature and begin to construct something that we call human society.”¹⁰

When a man and woman form a stable bond, they create a small sphere of trust and cooperation. Scaling this up, if the norm in a society is that each man and each woman will form such a bond (and not trespass on others’ bonds), it generates a network of micro-alliances that knit the social fabric together. Every family unit becomes a stakeholder in society’s stability; families can make alliances with other families (through kinship, friendship, trade) in a relatively stable way because the marital bonds are stable. Conversely, in polygamous or free-wheeling societies, family units are less stable and inter-family relations are more prone to distrust (e.g., feuds over women or uncertainty about lineage).

One can see the civilizational payoff of monogamy in the historical trajectory of the West. Classical Greece and Republican Rome—often cited as the cradles of Western civilization—both enforced monogamous marriage (for citizens) even while many other ancient societies allowed polygamy.¹¹ The Greek historian Polybius observed that monogamous, family-oriented norms differentiated the early Romans from some of their neighbors, and he believed this contributed to Roman social cohesion.¹² Rome’s Lex Julia de Maritandis Ordinibus under Augustus even imposed penalties on adultery and incentives for marriage, reflecting a policy view that stable monogamy was vital for the state.¹³ Tucker notes that the “founders of Athens and Rome…legislated sexual equity into their founding laws,” requiring one-man-one-wife as the standard.¹⁴

Anthropologist Jack Goody has argued that the Christianization of the Roman Empire, which definitively prohibited polygamy, was one of the key moments solidifying monogamy in the Western world.¹⁵ By the Middle Ages, the Catholic Church had not only forbidden multiple concurrent wives, but also forbidden divorce and remarriage (creating what some call “lifelong monogamy”) and forbidden consanguineous marriages (like marrying cousins) which kept kinship groups smaller. These policies forced society into a structure of small nuclear families and helped break down extended clan loyalties, inadvertently promoting broader social integration.

Joseph Henrich’s recent work The WEIRDest People in the World (2020) makes a strong case that the Church’s Marriage and Family Program was essentially a grand social experiment that reconfigured European society. By banning polygamy and incestuous marriage, and promoting free choice of partners, the Church undermined the large, patriarchal kin networks that had dominated kinship in early Europe.¹⁶

The result was a society where individuals were less bound by extended family ties and more free to trust and cooperate with others. In Henrich’s words, “the Church’s distinctive marriage and family norms…dissolved the densely interconnected clans of Western Europe into small, weak, and disparate nuclear families.”¹⁷

Monogamous marriage was a centerpiece of this new social order. The cultural “technology” at work was to channel all sexual and reproductive activity into exclusive, permanent bonds sanctioned by religion and law. This had profound second-order consequences: it reduced the salience of lineage and ancestry (since people stopped marrying cousins and creating big clans), increased people’s mobility and willingness to interact with strangers (you had to find spouses outside your kin group), and fostered impersonal social institutions. Over centuries, those monogamous, nuclear-family-based societies developed what we recognize as hallmarks of “civilization”: free markets, rule of law, democratic governance, and individual rights.

Historical analysis suggests that enforcing monogamy was a precondition or at least a co-factor for these developments. For example, it is noteworthy that monogamous marriage generally preceded the advent of democracy and political liberalization in Europe. Conversely, no country with widespread polygyny has ever sustained a liberal democracy on a large scale—monogamy appears to be part of the cultural package that supports equal citizenship. This makes intuitive sense: polygamy is fundamentally unequal, concentrating familial power in the hands of a male elite, whereas monogamy’s “one man, one wife” norm is intrinsically more equal and might nurture egalitarian ethos in the political sphere.

Political scientist Rose McDermott argues that polygyny is fundamentally at odds with liberal democracy because it entrenches patriarchal hierarchies and tends toward authoritarian control to manage the inherent conflicts. In polygamous societies, political power is often literally an extension of familial (patriarchal) power—think of tribal or clan-based governance. Monogamous societies, by breaking large kinship blocs, encourage more impersonal and meritocratic governance systems.¹⁸

Monogamy also functions as an economic leveling mechanism and growth promoter. In polygynous societies, wealthy men can use their resources to acquire wives, which is a form of wealth concentration (wives and their fertility are “assets” in a sense). In monogamous societies, even rich men can’t legally take more wives than poorer men; thus, they often invest their surplus resources in other ways—supporting community projects or investing in businesses—rather than in maintaining an oversized household.

At the same time, poorer young men in a monogamous society are not categorically cut out of the marriage market; they have a chance to marry if they are hardworking and law-abiding, which incentivizes productive behavior. Economists have modeled how monogamy can lead to higher per capita economic output because it more evenly distributes the opportunity to form a family, thereby motivating a broad base of males to engage in the economy and save for the future.¹⁹

By shifting male competition from fighting over mates to striving in commerce or professional domains, monogamy arguably channelled human ambition into less destructive avenues. Max Weber, in The Protestant Ethic, even hinted at the connection between the disciplined family life encouraged by certain religions and the rise of capitalism; monogamy underpins that disciplined family life.²⁰

Furthermore, governance and rule of law seem to flourish better under monogamous norms. Polygamous systems often intertwine with nepotism and patrimonial rule. Rulers in polygamous societies may have dozens of sons, sparking succession conflicts and power struggles (a pattern seen in the Ottoman Empire, Chinese dynasties, etc., which often had bloody conflicts among sons of different mothers). Monogamous succession (as in medieval Europe’s primogeniture norms) created clearer lines of inheritance and perhaps more stable governance structures.

Monogamy can be viewed as a technology or tool that societies discovered and refined to address a fundamental collective-action problem: how to reduce internal competition and violence to enable larger-scale cooperation. By solving the problem of distributing mates fairly (or at least, more fairly than in a polygamous setup), monogamy enabled societies to “lower the temperature” of young male competition, thereby achieving internal peace and cohesion.

Monogamy provided a stable domestic sphere, which in turn became the foundation for broader social stability. As Tucker succinctly states, “Sexual equity creates better societies.” By “sexual equity,” he means the relatively equitable access to marriage that monogamy offers.²¹However, some have even suggested that gender equality itself may be another (unintended ) consequence of monogamy.

To suggest that monogamous marriage is responsible for female empowerment sounds absurd on its face. Marriage is, after all, one of the most important instruments of patriarchy; effectively institutionalizing religious and cultural prescriptions of the inherently unequal roles assigned to the sexes. And yet, on one level, monogamy can be seen as protective of women’s interests: it guarantees each wife the exclusive sexual access and support of one husband, rather than having one man’s resources and attention divided among multiple wives.

Moreover, some historians argue that the Christian-Western monogamous model (at least in its ideal) elevated the status of women by emphasizing the partnership of husband and wife and by condemning extramarital sexual exploitation. Alexis de Tocqueville noted in the 1830s that American women, under strict monogamous norms, enjoyed a respect and moral authority in the home that was unusual by global standards of the time. He famously remarked that the “well-ordered” monogamous family was the bedrock of American democracy, and that many of the “disorders of society are born around the domestic hearth” when that order breaks down.²²

Women’s formal equality improved markedly in the West only in the last 150 years, even though monogamy was the norm for centuries prior. That said, it is arguable that monogamy was a precondition for the kind of gender-equality reforms we eventually saw. For instance, the suffrage and women’s rights movements first gained traction in monogamous societies; one reason is that when each man is tied to one woman in family life, men as a class have more incentive to listen to women’s concerns.²³ Henrich found that monogamy also tends to raise the age of marriage for females and increase their decision-making power in the household, which correlates with better outcomes in education and rights.²⁴

IV. The First School of Social Capital

Social capital refers to the networks of trust and reciprocity among people that enable cooperation for mutual benefit. Monogamous marriage is the first school of social capital – the initial institution where individuals learn to trust, commit, and sacrifice for others, thereby developing habits that extend to the broader society.

Monogamous societies, especially those with small nuclear families, have had to develop “generalized trust”—trust extended to people beyond one’s immediate kin. In societies organized around polygamous extended families or clans, trust tends to be very localized: you trust your kin group but are suspicious of outsiders. In many respects, polygamous, clan-based societies operate on that logic; loyalty to family trumps all, making it hard to sustain large-scale cooperation like honest bureaucracy, impartial courts, or community organizations that include unrelated members.

Monogamy, by breaking down large kin clusters, forces individuals to engage with non-kin in various institutions (from the marketplace to the town hall). This fosters a habit of treating others according to universal rules rather than nepotism. Indeed, one of the striking correlations Jonathan Schulz and colleagues (2019) found is that regions with a longer history of monogamous, Church-sanctioned marriage have higher levels of trust and fairness in anonymous social interactions.²⁵

This suggests that monogamy is not just about marriage per se, but radiates outward to affect the culture of trust. A man who grows up expecting to collaborate with a spouse as an equal partner and to deal with his in-laws as people rather than acquisitions may also be more amenable to norms of fair play and rule of law in society. Additionally, monogamy reduces the stark divides between haves and have-nots in the marriage market, which otherwise can breed resentments that carry over into other social cleavages.

Renowned observer of American democracy Alexis de Tocqueville wrote in 1835 that the strength of the United States was rooted in the strength of its marriages and families. He noted that the commitments and responsibilities learned in family life – between husband and wife, parents and children – were critical in fostering the “habits of the heart” necessary for a free, civic-minded people.²⁶ Marriage was thus not just a private arrangement but a public good, cultivating citizens who could engage in community and democratic governance.

Monogamous marriage – especially in its ideal form of a lifelong, exclusive union – demands virtues like loyalty, reliability, patience, and forgiveness. These virtues are exactly the kinds of personal qualities that translate into good citizenship and community involvement. A person who has learned to keep their word to a spouse, to work through conflicts at home, and to think of someone else’s wellbeing as tied to their own is arguably better prepared to cooperate with neighbors or colleagues in civic endeavors.

Sociologist Robert Putnam, in Bowling Alone (2000), documented the decline of social capital in late 20th-century America and noted that the retreat from marriage was one contributing factor. He found that married individuals are more likely to be involved in community associations, volunteer work, and even voting than their never-married counterparts, even after controlling for age and other factors.²⁷ Part of this is because marriage often connects people to community institutions (parents get involved in schools and youth sports, families attend religious services, etc.). But part is a selection effect too – people who are oriented toward commitment may both marry and join civic groups. Either way, monogamy aligns with greater social participation.

Marriage is often the formative experience of learning commitment. In a monogamous marriage, one must often sublimate immediate selfish desires for the sake of the relationship or family. This might mean compromising on decisions, providing care during a spouse’s illness, or investing in a future together rather than personal short-term gratification. Such experiences build what psychologists call social trust – the expectation that others can be reliable and that cooperation is worthwhile.

Children raised in stable monogamous families also internalize norms of trust and reciprocity. They see, modeled in their parents, a partnership of mutual obligation and (ideally) love. This provides them with a secure base to venture out and form their own trusting relationships. In contrast, children raised in very unstable family environments (e.g. serial breakups or fatherless households) may learn opposite lessons – that relationships are transient and trust is easily betrayed. Numerous studies have shown that children from stable two-parent families have higher levels of trust and social adjustment on average than those from broken homes, even controlling for income.²⁸

Consider also how monogamy reinforces a norm of reciprocity between the sexes. In a monogamous marriage, there is an expectation (in modern times, at least) of a partnership of equals, each contributing in complementary ways and respecting each other’s rights. This mutual respect, when carried into the public arena, supports the idea of equal dignity of all individuals. A husband and wife who learn to solve problems together set an example for cooperation that can scale up to town meetings and PTA boards. Indeed, de Tocqueville observed that American men consulted their wives on moral and even political questions, valuing their insight – a far cry from societies where women (especially multiple wives) are kept sequestered with little public voice.²⁹

All this is not to say that monogamous marriage automatically creates perfect citizens—clearly, unhealthy marriages or dysfunctional families can do the opposite. But on balance, the normative commitment of monogamy sets a tone for pro-social behavior. When society holds up the ideal of a faithful, cooperative marriage, it is simultaneously holding up an ideal of faithful, cooperative citizenship. This is why many philosophers (from Confucius to Locke) placed marriage and family at the heart of their visions of a good society. They recognized that marriage is a microcosm of the social contract: an agreement to share one’s life and restrain one’s impulses for the good of the union, paralleling how citizens agree to cede some freedoms and abide by laws for the common good. Monogamy sharpens that parallel by making the spousal relationship exclusive and enduring, thus more closely mirroring the loyalty one owes to country or community (as opposed to divided loyalties in polygamy).

V. Hyper-Individualism and the Decline in Trust

Modern liberal societies prize individual freedom – the right of each person to pursue happiness in their own way, so long as it doesn’t harm others. This freedom has yielded immense benefits in creativity, economic dynamism, and personal fulfillment. Yet, taken to an extreme, individualism can morph into hyper-individualism, where social bonds and communal responsibilities are weakened in favor of personal autonomy above all.

Many social critics have noted that Western societies today struggle with atomization: people feeling disconnected, institutions from family to churches losing authority, and a general ethos of “looking out for oneself” often eclipsing duty to others. In this context, monogamy stands out as a voluntary commitment that inherently limits individual freedom for a greater mutual good. When two people marry, they willingly give up some of their personal latitude – agreeing to forsake all others romantically, to share finances, to care for one another even in hardship. This is a self-imposed check on one’s autonomy, motivated by love, loyalty, and often a sense of societal expectation. In doing so, monogamy serves as a cultural counterbalance to pure individualism, reminding society that true freedom is not merely the absence of ties, but the ability to choose one’s obligations wisely and embrace them.

Think of liberal democracy as a delicate system that needs a communal glue to function. If everyone simply pursues their own interest with no regard for collective well-being, democracy degrades into factionalism or anomie. Traditionally, institutions like religion, civic associations, and family provided the glue – they inculcated virtues of self-restraint, empathy, and responsibility. Of these, the family (and particularly the bonded marital pair at its core) is arguably the most fundamental. A society of intact families can moderate the excesses of individualism because almost every individual is embedded in a small unit where they are not the sole center of the universe; they must consider spouses and children.

On the flip side, if monogamy declines and fewer people have these binding commitments, a liberal society can tilt towards excessive individualism or even what sociologist Emile Durkheim called anomie (a lack of social norms and connections). Durkheim’s classic study on suicide (1897) found that unmarried individuals, especially unmarried men, had significantly higher suicide rates than married men, which he attributed to the “egoism” of being unattached – having less meaning and fewer obligations in life.³⁰ While times have changed, recent data still show that single, especially never-married, adults report lower levels of happiness and higher levels of loneliness on average than married adults. Beyond personal well-being, the worry is that a society of isolated individuals may not defend institutions of liberty when challenged, or may not cooperate in crises, because their primary loyalties are thin

In recent decades, many societies, particularly in the West, have seen a marked decline in monogamous marriage. Fewer people are marrying³¹, those who do marry later in life, and more relationships are short-term or informal. Divorce, while leveling off in some countries, remains high,³² and the rise of phenomena like “serial monogamy” (multiple marriages or partnerships over a lifetime), single parenthood, and openly non-monogamous arrangements all point to a weakening of the once-dominant norm of one life, one spouse. It is worth examining the social consequences of this trend. Do the predictions of theorists like Tucker and Henrich hold true in reverse—i.e., as monogamy recedes, do we see reductions in social trust, stability, and prosperity? While it’s an ongoing story, early indicators raise cause for concern that the retreat from monogamy is indeed connected to some negative outcomes at the societal level.

One clear consequence is the emergence of more “transactional” relationships, especially in contexts like dating apps and casual dating culture. When marriage is viewed as optional or postponable, the dating market can start to resemble a low-commitment marketplace where individuals treat partners as interchangeable commodities. Such attitudes, if widespread, can bleed into a general wariness in social interactions. If one learns early on that intimacy can be fleeting and others might discard you when inconvenient, that doesn’t bode well for trusting fellow citizens or forming lasting friendships either.

It may be no coincidence that surveys show trust in institutions and in other people has declined in tandem with the decline of marriage rates in many Western countries since the 1970s.³³ While many factors contribute to declining social trust (economic inequality, social media, etc.), family fragmentation is one often overlooked piece. Sociologist Charles Murray, in Coming Apart (2012), illustrated how the decline of marriage among the working class in America corresponded with a host of community-level problems: fewer stable homes meant more youth crime, drug use, and a collapse of civic organizations in those communities.³⁴ In contrast, communities where marriage remained commonplace retained greater social cohesion and civic life.

With monogamy’s decline, we also face the loss of a shared cultural script for intimate life. In the past, the vast majority of people expected to follow a life script of finding a mate, marrying, and raising a family within that bond. Not everyone did so successfully, but it was a common aspiration that provided direction and meaning. Now, young people face a dizzying array of choices and little consensus: Should they prioritize career or family? Is marriage worth it or should one just focus on self? The absence of a clear social norm can create anxiety and analysis paralysis, leading some to opt out altogether (hence rising lifelong singlehood).

Moreover, when people do want marriage, the dating culture shaped by low-commitment norms can actually make it harder to achieve, creating a mismatch of expectations (e.g., those looking for a serious partner get discouraged in a casual scene). This in turn can feed cynicism about relationships, a sense that stable monogamy is “unrealistic” or old-fashioned. A kind of cultural feedback loop can set in: as monogamy becomes less common, people have fewer role models of it working well, making them less likely to attempt it themselves. Societies like Japan, where marriage rates and birth rates have plummeted, illustrate a possible endgame: large portions of the population simply disengaging from romantic and family life.³⁵

Ultimately, the weakening of monogamy raises the question of what will sustain the social trust and cohesion needed for complex society. If intimate trust between spouses is harder to come by, will people compensate with other forms of association? Or will we drift into greater isolation? Already, policymakers and scholars voice concern about declining social trust in many democracies, evidenced by lower interpersonal trust survey scores and eroding confidence in institutions. While not solely due to family change, it’s interwoven.

For example, if fewer people are married or have close family ties, they may turn to more identity-based affiliations (like political tribes or online communities) to find belonging³⁶. These are often more polarized and less bridging than the traditional ties of family and neighborhood. Thus, a potential consequence of monogamy’s decline is a society that is both more fragmented and more polarized – fragmented in personal life and polarized in public life, as people seek solidarity in narrower identity groups rather than in the broad, cross-cutting institution of family which historically connected different families and generations.³⁷

Most indicators suggest that the retreat from monogamy has not produced a utopia of liberated individuals with rich social lives; rather, it has coincided with rising loneliness, mistrust, and instability. In light of this, some thinkers advocate a cultural renewal of monogamy—not as a coercive mandate, but as a valued norm to be encouraged for those who are open to it.

VI. Conclusion

Monogamy, when viewed through the wide lens of history and across culture, emerges as far more than a private arrangement between couples. It is one of the great technologies of social organization that humans have developed—a set of norms and commitments that harness basic human impulses (love, sexuality, pair-bonding, parental care) and direct them toward the creation of resilient social structures. The institution of monogamous marriage played a pivotal role in fostering civilizational achievements: it helped reduce internecine conflict, enabled governance based on equality and consent, improved the welfare of women and children, undergirded economic development, and generated the trust and social capital necessary for democracy and modern life. Monogamy solved deep problems around how to regulate and channel the single most powerful human drive necessary for the survival of the species: how to allocate mates fairly, how to bind males to the rearing of offspring, how to extend cooperation beyond kinship, and how to instill habits of commitment and reciprocity in each generation.

Critics are correct that monogamy is not an innate biological imperative; it is not entirely “natural.” It must be learned, culturally transmitted, and reinforced by culture and norms. It has its trade-offs and discontents (not all marriages are happy; not all individuals thrive in pair-bonds). Yet, the weight of scholarly evidence underscores that societies which have embraced monogamy have, on balance, outpaced those that have not in terms of social stability, equity, and flourishing.

Monogamy has been one of the most successful social innovations in human history. It exists within the most personal and private sphere of our lives, yet exerts enormous influence on civilization itself. Because it is far too important, it should remain lightyears away from the coercive power of the state. At the same time, no liberal society can survive in the absence of culture that inculcates virtue. Monogamy is not only a private virtue codified in vows and sealed by ancient rituals, it is also a public virtue enforced by norms and expectations.

Monogamy transforms us in fundamental ways. It teaches us responsibility, mutual sacrifice, and the discipline of commitment. It orients us toward seeing others not as instruments of personal gratification but as persons with equal dignity and intrinsic worth. It shifts our perspective from fleeting self-interest to a broader, long-term investment in community and shared destiny.

A culture that embraces monogamy inculcates these values not just through moral instruction, but through the lived experience of individuals bound together in a commitment that shapes character. Monogamy teaches patience, trustworthiness, and the ability to subsume individual desires for a greater shared purpose—traits essential not just for stable families, but for the foundations of democracy itself. When marriage is treated as merely an arrangement of convenience or an avenue for self-fulfillment, these deeper transformations are lost, and in their place emerges a culture that prioritizes autonomy over duty, pleasure over permanence, and personal gratification over relational responsibility. Doesn’t that feel awfully familiar in the state of the world today?

If monogamy fosters an ethic of responsibility and mutual obligation, what happens when a culture is structured around sexual freedom without commitment? Does a society that encourages transactional relationships erode the very trust and meaning that human beings crave? These are the questions we must grapple with as we consider not only how monogamy has shaped civilization, but how its decline may shape who we become.

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