Why Nonmonogamy Feels So Wrong: A History of Mononormativity

Why does this feel like betrayal even when everyone consented?

Why does my body think one structure is moral and another is wrong?

Is this just human nature, or did someone build this?

Why do I feel disgust at the thought of my partner loving someone else, when I can't explain why?

These are the questions underneath the questions. Before anyone asks me whether they're polyamorous or capable of non-monogamy, they're carrying a quieter belief that they've never examined: that monogamy is simply how love is supposed to work. That anything else is a deviation. A failure of character, commitment, or maturity.

That belief feels like instinct. It is not instinct. It has a paper trail.

What you believe about how love should work is the outermost layer of the three-layer model I use in my practice: ideology, identity, capacity. Ideology is the script you inherited before you knew you'd inherited anything. This post is about where that script actually came from. Not where it claims to come from. Where it came from.

I want to be honest about something before I start. Some of this history is contested. Historians argue about timelines and causes the same way any field argues. I'm not going to smooth that over to make a cleaner case. The case is strong enough to survive the argument intact, and you deserve a true account, not a tidy one.

Why nonmonogamy feels wrong (and why that feeling isn't instinct)

Nonmonogamy feels wrong because the belief that monogamy is the only legitimate way to love was built into you before you were old enough to question it, not because that belief reflects something true about human nature.

The claim isn't that monogamy is bad, or that everyone should be non-monogamous, or that people who choose lifelong partnership with one person are conditioned and unfree. Plenty of people examine the conditioning, keep digging, and land on monogamy as their honest, chosen structure. That's a real and valid outcome of this work.

The claim is narrower and more specific: the belief that monogamy is the only legitimate, moral, "natural" way to love was built by particular people, for particular reasons, at particular points in history. Those reasons were rarely about love. They were about property, paternity, labor, racial control, and the management of populations.

When you understand where a rule came from, you get to decide whether it still serves you. That's the whole point of this. Not demolition. Choice.

Did monogamy start as a way to control property and inheritance?

Yes. The most well documented thread starts with property, not love.

Friedrich Engels published The Origin of the Family, Private Property and the State in 1884, drawing on the anthropological fieldwork of Lewis Henry Morgan. His argument was that monogamous marriage did not emerge from romantic love at all. It emerged from the need to guarantee a clear paternal line so that private property could be passed from a father to his biological sons with no ambiguity. Engels described monogamous marriage as not in any way the fruit of individual sex love, calling it instead the first form of family based not on natural conditions but on economic ones, on the victory of private property over primitive communal property.

Before the accumulation of private property and surplus wealth, descent in many societies was traced through the mother, because maternity is observable and paternity, without enforced fidelity, is not. Once wealth accumulated and inheritance became something worth controlling, the question of who a child's father was stopped being incidental and started being the whole point. Engels argued that the origin of private property created the problem of inheritance, and the solution to that problem was monogamy: a system that let fathers pass property to sons with confidence.

This is worth sitting with. The fidelity requirement that monogamy is built on was never symmetrical. Engels pointed out that the sequestration of women and enforced sexual fidelity applied only to women, never to men, and that this control was the only way to guarantee that property passed through the male line to sons of undisputed parentage. He called the resulting patriarchal monogamous nuclear family the "perfected form" of marriage for the transmission of property and the institutionalisation of male control over women.

This is not a fringe reading. It's foundational to an entire branch of feminist and Marxist historical analysis, and it lines up with what anthropologists have separately documented: Engels described pre-property societies as egalitarian communal kinship groups with no private ownership of wealth, no exploitation, no nuclear family as it exists today, and no systematic oppression of women.

So when the feeling arrives that non-monogamy is a threat to a "real" relationship, one honest question is: a threat to the relationship, or a threat to a system of ownership that got bolted onto the relationship a long time ago, for reasons that had nothing to do with you?

How Christian theology made pleasure itself the sin

Christian theology, largely through Augustine, framed sexual pleasure rather than relationship structure as the actual problem, which is why shame around nonmonogamy often feels older and deeper than any logical objection to it. Property explains the structure. It doesn't fully explain the shame. For that you have to go to the Church.

Augustine of Hippo, writing in the late fourth and early fifth centuries, did more than almost anyone to shape Western Christianity's relationship to sex, and his own writing tells you exactly where his framework came from. He taught that the fall of Adam had placed human sexuality under the compulsive power of concupiscence, the passionate and uncontrolled element of lust, and that all sexual intercourse, even within marriage, was tangled up with this inherited corruption. Marriage itself was "honorable and permissible," and the stated purpose of sex within it was procreation, though Augustine conceded it was "pardonable" if a married couple enjoyed each other without that intention. Celibacy, in his view, remained the higher path.

Later interpreters of Augustine clarified the logical structure underneath this: sex aimed at procreation wasn't sinful, but sex known to be infertile was treated as sin. Pleasure itself, untethered from reproduction, was the problem. Not the relationship. Not the consent. Not the love. The pleasure.

This idea didn't stay in a monastery. Augustine's views became the foundation for much of the Roman Church's teaching on marriage, on why procreation is its central purpose, on why birth control and divorce are forbidden, and on why sexual restraint is the ideal. Centuries of Western sexual ethics, including a great deal of what now gets passed off as "common sense" or "how relationships are supposed to work," sits on this foundation: pleasure is suspect, sex needs a procreative alibi, and your body's wanting is evidence of inherited corruption rather than evidence of being alive.

You don't have to be religious for this to live in you. It got secularised, repackaged as psychology, repackaged again as romantic convention, and handed to you anyway.

How eugenics turned sexual purity into a science

By the late nineteenth century, sexual purity stopped being only a theological project and became a scientific one, or at least one dressed in the language of science, used to justify the control and sterilisation of anyone judged sexually "promiscuous."

The social purity movement, active across English-speaking nations from the late 1860s to around 1910, set out to abolish prostitution and any sexual activity considered immoral by Christian standards, and it became deeply entangled with the contemporaneous feminist, eugenics, and birth control movements. Feminists in the movement were genuinely concerned about the sexual exploitation of women, while eugenicists were concerned with something else entirely: preserving what they called the "fittest" citizens, which in practice required controlling white women's chastity specifically. Two different agendas, one shared mechanism: control of who has sex with whom, and under what conditions.

Through the early twentieth century, sexual purists and birth control advocates, who saw themselves as opposites, were actually linked by a shared belief that unregulated sexual indulgence was dangerous, and the scientific language both sides reached for to make that case was eugenics. Organisations like Anthony Comstock's Society for the Suppression of Vice didn't just go after pornography. They went after birth control information, diaphragms, and any printed material that suggested sex could exist for reasons other than procreation within marriage. The 1873 Comstock Act made distributing contraceptive information a federal crime in the United States, a law that stayed substantially on the books for decades.

The eugenics side of this is harder to look at directly, and worth looking at directly anyway. The early American eugenics movement was, underneath its stated goal of improving the human race, a project for eliminating anyone who didn't fit a white, non-immigrant, upper-class profile, and that included women who were judged sexually promiscuous, alongside Black people, immigrants, poor people, and disabled people. Eugenicists argued openly that sterilising people they judged to carry defective traits would, within a few generations, eliminate problems they listed as criminality, alcoholism, "sexual promiscuity," rebelliousness, and manic depression. The movement peaked in North America through the 1920s, and its German counterpart, which shared its scientific foundations, peaked in the following decade with consequences the world has not forgotten.

This is the part people don't want to trace all the way through, because it's uncomfortable, and it needs to be traced all the way through anyway. The idea that sexual restraint is a sign of moral and even genetic fitness, and that sexual freedom or multiplicity is a sign of degeneracy that threatens the health of the population, was not a metaphor to the people who built it. It was literal population science, and it was used to justify the sterilisation of disabled people, poor people, and people of color on the explicit grounds that their reproduction, and their sexuality, was a danger to be contained.

When shame about wanting more than one partner shows up in your body as something that feels almost eugenic in its intensity, like you are somehow contaminating something by wanting this, that's not paranoia. That association was built on purpose, by people, on record, citing science that has since been thoroughly discredited.

Is the nuclear family natural, or was it built?

Neither answer is fully right. The household shape is older than industrial capitalism, but the belief that it's the only moral way to live is a much more recent invention, and that distinction matters more than either side of the popular debate admits.

The popular version says: the nuclear family was invented by the Industrial Revolution, full stop, end of story, ancient humans lived in extended kin groups and capitalism atomised us into isolated breadwinner households. That story is partly true and partly wrong, and the wrong part matters.

Historians Peter Laslett and Alan MacFarlane, working through English parish records and other demographic sources, found that the nuclear family, meaning a mother, father, and children in a single household, was actually the dominant arrangement in England stretching back to at least the thirteenth century, centuries before industrialisation. The "we used to live in extended multigenerational households until factories ruined everything" story doesn't hold up as a universal claim, at least not for England.

What industrialisation did do is something more specific and, I'd argue, more useful to understand. As industrialisation and early capitalism advanced, men, who were viewed as the strongest source of labor for an industrial economy, left the home to work in factories, while women were assigned to stay home and manage the household and children. Smaller family units became practically necessary for urban living conditions and the demands of factory-based economic shifts, and the Industrial Revolution reinforced rigid gender roles, with men as breadwinners and women as unpaid domestic labor.

So the nuclear family unit itself may be older than the factory system. But the ideology that turned it into a moral ideal, the breadwinner husband and the domestic wife as the only correct configuration of adult life, is much more recent and much more traceable. Sociologist Talcott Parsons theorised in 1951 that industrialisation had driven the development of the nuclear family as the functionally ideal unit for an industrial economy, a theory that became extremely influential in shaping how mid-century Western society talked about what families were "supposed" to look like. Historian Stephanie Coontz has spent much of her career documenting how the 1950s nuclear family, the version most people actually picture when they imagine "traditional," was not a return to some ancient pattern but a historically specific, economically engineered arrangement that depended on a postwar economic boom that has not existed since.

Coontz put it directly: to mourn the decline of the two-heterosexual-parent nuclear family is to be nostalgic for "the way we never were," for a situation that never included everyone and by which few were actually well served. It was, in her words, an edifice designed to keep women's labor cheap or free.

Here's the honest synthesis. The household shape (two parents, their children, one roof) has older and more tangled roots than the single-cause story admits. But the belief that this shape is the only correct, moral, complete way to organise adult intimate life, with one breadwinner and one domestic partner and total emotional and sexual exclusivity, that belief is a specific twentieth-century production, built to fit a specific economic system, sold back to us as eternal truth.

Knowing this doesn't require you to reject the nuclear household if that's genuinely what you want. It requires you to notice that "this is just how families are supposed to be" was manufactured, marketed, and is still being marketed, by people who needed you to believe it.

How colonisation criminalised other ways of loving

Colonisation didn't just spread compulsory monogamy through culture, it enforced it through law, criminalising existing kinship structures and tying legal and economic survival to the monogamous nuclear household. The last thread is the one I think gets buried the deepest, and it's the one that connects everything else to power on a global scale.

Compulsory monogamy was not just an internal Western development. It was exported, by force, as part of colonisation.

Kim TallBear, an Indigenous studies scholar and enrolled member of the Sisseton Wahpeton Oyate, has built much of her academic work around this history. In her lecture "Settler Love Is Breaking My Heart," she argued that compulsory monogamy functioned as a tool of the settler-colonial system, and that relationships extending beyond monogamy can function as a tool for decolonisation and the restoration of Indigenous ways of life.

TallBear has described how, at the same time settler monogamy and marriage were being solidified as central to American and Canadian nation building, Indigenous peoples in those countries were being physically and conceptually restrained inside colonial institutions, including residential schools, churches, and missions, explicitly designed to "save the man and kill the Indian." Part of that "saving" meant coercing and indoctrinating Indigenous people into the monogamous, couple-centric nuclear family. She notes that Kim Anderson, a Cree and Métis feminist scholar, has written that one of the central targets of colonialism was the Indigenous family structure itself, in which women had often held positions of authority and controlled property, a power the colonial state specifically targeted by tying legal standing to marriage over other, older forms of kinship obligation.

This wasn't unique to North America. Nana Darkoa Sekyiamah, author of The Sex Lives of African Women, has explained that in Ghana, British colonisers explicitly framed the multiplicity of relationship structures that already existed there as immoral, while institutionalized heterosexual monogamous marriage was promoted as the "civilized" form of kinship. The result, she says, was the loss of an entire diversity of relationship types, replaced by a form of relationship that was never native to the culture at all but became treated as the norm.

The mechanism repeats across very different colonised regions: by criminalising plural marriage and other existing relational structures, colonisers weakened Indigenous communities and disrupted their social cohesion, which made monogamy not a moral upgrade but a practical necessity for survival under colonial law. This legal enforcement reinforced gender hierarchies that had not previously existed in the same form, and embedded European cultural norms directly into the colonised society's legal and social fabric. Christian missionaries did much of the on-the-ground work of this, spreading the specific theological claim that monogamy was the only morally acceptable form of intimate relationship, the very claim that traces back to Augustine.

This is the part where all five threads meet. The same property logic that shaped European marriage law was used as the justification for dismantling Indigenous land tenure and kinship systems, because land tenure rights were attached to marriage in ways that tied people's economic survival directly to that institution, and enforcing monogamous heterosexual coupledom alongside the privatised single-family household became, by the late nineteenth century, an explicit official national ideal enforced through interlocking state policy. By individualising people into small marriage-based household units, this process broke apart collective Indigenous identities along with collective land, dividing both into smaller individualised units that could be allotted and seized, a process through which much Indigenous land was ultimately lost and existing kinship structures were rendered legally illegitimate.

This isn't a story about one culture being more "evolved" than another in how they structured intimacy. It's the opposite. Even the foundational anthropological theory used to justify ranking societies by their family structures, the idea that humans progressed from "primitive promiscuity" through matrilineal kinship and finally "advanced" to monogamy, has been recognised by anthropologists as deeply flawed, built explicitly to position Indigenous groups as less developed in order to justify settler colonialism.

If your body carries a quiet, unexamined association between monogamy and civilisation, and between other relational structures and primitiveness or moral disorder, that association has an actual history. It was built to do exactly that work.

What this means for the shame you're carrying

None of this is offered as an argument that you should be non-monogamous. Some people will read all of this, sit with it, and still choose monogamy, freely and completely. That's not a failure of the argument. That's the argument working correctly. The goal was never to replace one mandatory structure with another. It was to show you that there was never a mandatory structure to begin with, only a series of specific historical actors with specific historical interests who needed you to believe there was.

What I want you to take from this is much simpler. The shame, the disgust, the gut-deep sense that wanting more than one partner makes you morally compromised: none of that arrived in your body as pure, unconditioned truth. It arrived through a transmission line that runs through property law, a particular bishop's theology of original sin, a pseudoscience that justified forced sterilisation, a mid-century economic arrangement sold to you as eternal nature, and a colonial project that destroyed entire kinship systems and called the destruction civilisation.

That doesn't mean the feeling isn't real. It is real. Your nervous system doesn't know the difference between an old wound and an inherited one. It just knows it's activated.

What it means is that the feeling is not evidence of moral truth. It's evidence of successful transmission. And transmissions can be examined. Beliefs that survive examination get to stay, fully and honestly yours. Beliefs that don't survive examination can be put down, and you don't have to carry them out of obligation to people who built them for reasons that had nothing to do with you and everything to do with property, control, and the management of bodies they had decided didn't belong to themselves.

Work with me on this

If this history is landing somewhere in your body, that's worth paying attention to. Examining the inherited beliefs underneath your relationship choices is the first layer of the work I do with clients, alongside the deeper layers of identity and capacity. You don't have to do this excavation alone.

I offer relationship coaching for people exploring relational diversity, whether you're questioning monogamy, navigating non-monogamy, or simply trying to understand which of your beliefs about love are actually yours. I work in single sessions (55 minutes) and double sessions (1 hour 55 minutes), in-person from my studio in Salt River, online with clients worldwide, and through home visits. Every new client gets a free 15-minute exploratory call to check fit before we begin.

Amy Nelson, Shamanic Therapist and Relationship Coach Salt River, Cape Town

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FAQ

Does this mean monogamy itself is a colonial or oppressive structure?

No. Monogamy as a relationship two people freely choose is not the same thing as mononormativity, the belief that monogamy is the only legitimate way to love and that everyone owes it to each other by default. Plenty of people, across plenty of cultures and historical periods, have chosen pair bonding for reasons that have nothing to do with property or control. What this history targets is the compulsory, default, unquestioned status of monogamy, not the structure itself.

If the nuclear family predates industrialisation, doesn't that undermine the whole argument?

It complicates one specific claim, that the household shape was invented wholesale by capitalism. It doesn't undermine the larger argument, because the household shape and the ideology around the household shape are two different things. The structure may be older. The belief that it's the only moral structure, enforced through law, religion, and economic incentive, is the part with the more recent and well documented history.

Why does this matter if I'm not interested in non-monogamy?

Because mononormativity doesn't just regulate non-monogamy. It regulates anyone who deviates from the script in any direction: people who divorce, people who co-parent without romantic partnership, people who prioritize friendship over romance, people who are single by choice. Understanding where the script came from gives everyone more room to build a life that actually fits them, inside or outside a monogamous structure.

Isn't it possible that monogamy also has evolutionary or biological roots, separate from all this social history?

There's ongoing scientific debate about pair bonding in human evolutionary history, and that debate is real and unresolved. What's not seriously contested is that the moral and legal mandate for monogamy, the idea that it's the only acceptable structure and that violating it makes you a bad person, is a social and historical product layered on top of whatever biological tendencies exist underneath. Biology might explain an inclination. It doesn't explain a law.

How is this different from just blaming religion or colonialism for my personal feelings?

It's not about blame. It's about accuracy. Knowing that a belief was constructed by specific historical actors doesn't erase the belief or insult the people who hold it. It just gives you the option of asking whether the belief is actually yours, examined and chosen, or whether it's running on autopilot from a source you never agreed to.

Where do I start if I want to actually examine my own conditioning around this?

Start with noticing, not changing. Notice when the word "should" shows up in your thinking about relationships. Notice where disgust or moral judgment arises and ask where you first learned that response. This is slow work, and it benefits enormously from support, whether that's a therapist, a coach, or a community of people doing the same excavation.

References

Engels, Friedrich. The Origin of the Family, Private Property and the State. 1884.

TallBear, Kim. "Settler Love Is Breaking My Heart." Harper Lecture, University of Chicago, November 2020. Also see TallBear, "Couple-centricity, Polyamory and Colonialism," Unsettle (Substack newsletter).

Anderson, Kim. Cited in TallBear, "Disrupting Settlement, Sex, and Nature."

Sekyiamah, Nana Darkoa. The Sex Lives of African Women. Interview in Novara Media, "Challenging Monogamy Is a Political Act," 2022.

Coontz, Stephanie. Marriage, a History: How Love Conquered Marriage. Viking, 2005.

Laslett, Peter, and Alan MacFarlane. Demographic research on English household structure, cited in "The Real Roots of the Nuclear Family," Institute for Family Studies.

Parsons, Talcott. The Social System. 1951.

Clark, Elizabeth A., ed. St. Augustine on Marriage and Sexuality. Catholic University of America Press, 1996.

Bouche, T., and Rivard, L. "America's Hidden History: The Eugenics Movement." 2014.

"Social Purity Movement." Historical overview of the 1860s-1910 movement and its entanglement with eugenics and birth control advocacy.

Kim, Ji-Youn. "A Decolonial, Queer Praxis of Anti-Mononormativity in Therapeutic Practice." Includes citation of Rifkin, Mark, on settler state policy and monogamous couplehood as national ideal.