Feb 6, 2026 5 min read

An Imperfect Union | How Monogamous Marriage Made Modern Civilization

“[W]hoever destroys human marriage destroys the home, the city, and the whole human race.” ¹ - Gaius Musonius Rufus

Marriage is one of the cornerstones of civilization. Yet, despite centuries of its widespread practice in almost every known culture, it is a puzzling phenomenon given the prevalence of divorce and infidelity. Why develop a law-binding system whereby one man and one woman must remain exclusive to each other when, biologically, humans have been documented as slightly polygynous? ² To answer this, we must study the function of marriage and who the primary benefactors are. Certainly, many of the advantages are self-evident such as love and support from a partner, whether financially or emotionally, but what is often overlooked is the stability marriage creates for families, carrying over to the larger whole of society.

Pairing men and women into a legally binding union mitigates a number of common issues that would otherwise guarantee unhealthy chaos for multiple parties. These include the possibility of sex-ratio imbalance where either a large subset of men or women remain perpetually single, resulting in a sexual marketplace where a low supply of eligible bachelors and bachelorettes have access to all the demand. Those who take advantage of this will have more opportunities to capitalize on this instability, increasing the frequency of mate-poaching and infidelity. The more pertinent problem, however, is the well-being of children who are the most at risk when both biological parents have no legal obligation to each other. Marriage has less to do with convention and more to do with finding an adequate solution to what evolutionary psychologists call men's and women’s competing mating strategies.

Men, on average, desire variety and quantity of sexual partners, whereas women prefer quality and stability. These competing desires have evolved and, as a result, developed two different paths of sociosexuality, which is one’s willingness to have uncommitted sexual relationships. Men, for example, tend to be higher in sociosexuality compared to women. ³ This dynamic creates scenarios where the reproductive success of one can potentially come at the expense of the other. Marriage, essentially, rectifies this issue by offering a compromise: men will remain faithful as long as the women they’re with give them exclusive sexual access and bear only their children, and women will remain faithful so long as they and their children are protected and provided for. It is an agreement that redirects men’s and women’s competing desires towards a mutual self-interest, allowing society to not only survive—but thrive. From this perspective, monogamous marriage, is essential to the rapid growth and stability of modern civilization.

In “The WEIRDest People in the World,” American Anthropologist Joseph Henrich states that:

“Monogamous marriage changes men psychologically, even hormonally, and has downstream effects on societies. Although this form of marriage is neither ‘natural’ nor ‘normal’ for human societies and runs directly counter to the strong inclinations of high-status or elite men—it nevertheless can give religious groups and societies an advantage in intergroup competition. By suppressing male-male competition and altering family structure, monogamous marriage shifts men's psychology in ways that tend to reduce crime, violence, and zero-sum thinking while promoting broader trust, long-term investments, and steady economic accumulation. Rather than pursuing impulsive or risky behaviors aimed at catapulting themselves up the social ladder, low-status men in monogamous societies have a chance to marry, have children, and invest in the future. High-status men can and will still compete for status, but the currency of that competition can no longer involve the accumulation of wives or concubines.” ⁴

British journalist and author Louise Perry also echoes these sentiments in, “The Case Against the Sexual Revolution,” arguing that:

“While the monogamous marriage model may be relatively unusual, it is…spectacularly successful. When monogamy is imposed on a society, it tends to become richer. It has lower rates of both child abuse and domestic violence, since conflict between co-wives tends to generate both. Birth rates and crime rates both fall, which encourages economic development, and wealthy men, denied the opportunity to devote their resources to acquiring more wives, instead invest elsewhere: in property, businesses, employees, and other productive endeavours.” ⁵

In short, monogamous marriage levels the playing field for everyone, stabilizing the sexual marketplace while, at the same time, redirecting resources towards the economic growth of our society. It places checks and balances on men’s and women’s competing mating strategies through social enforcement and civil law. Moreover, it gives the next generation a better chance for success, having children with the investments of both biological parents to help them excel in life.

The breakdown of the monogamous marriage system will have downturn effects, ultimately weakening the foundations of our modern civilization. Already, we see cracks forming with the rise of singledom and single-parent households. In the U.S. alone, 23% of children are raised by a single parent, and across the world in many countries, the rates have been increasing. ⁶ Alternative mating styles such as polyamory have become popular in certain circles, particularly among young adults, and are often described as ethical monogamy despite higher relationship instability due to lower commitment levels and stigmatization. ⁷ Ultimately, we have become a society that wishes to have the benefits of civilization with none of the sexual restraints required in keeping it. We put so much value on individual freedom, at any cost, that we failed to instill the virtues needed to use it wisely. We have become, as anthropologist J.D. Unwin states in Sex and Culture:

“[T]he foolish boy who desires both to keep his cake and to consume it. Any human society is free to choose either to display great energy or to enjoy sexual freedom; the evidence is that it cannot do both.” ⁸

Monogamous marriage is an imperfect union, but it is the only solution that reconciles the competing sexual strategies of men and women. It is not for the direct benefit of either sex; rather, it is an institution designed to stabilize unions for the protection and long-term success of the next generation by having both biological parents raise their offspring together. The nuclear family, despite its critics, has been one of the greatest achievements of the human race. While it might seem old, outdated, or unfashionable for some, its necessity outweighs any of its flaws. In hindsight, it serves an essential, yet often overlooked, function—maintaining the social order by preserving society at its most fundamental level—the family unit.

“Whoever attacks marriage…undermines the basis of all moral society…Marriage is the beginning and the pinnacle of all culture.” ⁹ - Johann Wolfgang von Goethe