When most of us hear the word “marriage,” we think of a monogamous union between a man and woman. And this is a perfectly reasonable inference considering we live in a world where some 75% of the population lives in countries where polygamy is illegal.
But this wasn’t always the case.
In fact, for almost all of written human history, the vast majority of humans lived in polygamous societies.
Noah’s father, Lamech, and his two wives are the first polygamists mentioned in the Old Testament, but they are by no means the last. Abraham conceives his first son, Ishmael, with his first wife’s servant Hager, and Abraham later went on to take a third wife, Keturah.
Abraham’s grandson, Jacob, did him one better, taking four wives while King David managed to end up with eight. These men were all lightweights compared to King Solomon who had a reported 700 wives.
Evidence supporting the ubiquity of polygamy in the ancient world goes back even further than that. Stone tablets recovered from the ruins of a palace destroyed by Hammurabi notes the local king inherited a 350-woman harem from his predecessor and managed to add another 300 to that.
We also know that these concubines were not limited to just the kings of ancient Mesopotamia. The Code of Hammurabi, one of the first written legal codes in human history, set detailed laws governing the relations between husband, wife, concubine, slave, and master.
Under the Hammurabi code, if a wife produced no children, the wife could allow her husband to conceive with one of her servants instead. But if the wife refused sexual access to her servants, then the husband was allowed to take a second wife.
Wealthy men who could afford slaves were also allowed to have sex with their slaves whenever they wanted and were even given the option of adopting their slave offspring if they wanted to make them legitimate.
Moving forward in history, we see that virtually all large human civilizations were polygamous. The rulers of ancient China, India, Africa, the Americas, and even Europe all kept hundreds, sometimes thousands, of women at their disposal. Anthropologist Dr. Laura Betzig has noted that in each of these societies “powerful men mate with hundreds of women, pass their power on to a son by a legitimate wife, and take the lives of men who get in their way.”
This didn’t really start to change until some 2000 years ago, and even then, change was slow. It is a tough sell getting the wealthy and powerful men who control society to give up their privilege of monopolizing female companionship.
But ultimately monogamous communities ended up out-breeding and out-competing polygamous ones. In some cases, like the Aztecs, polygamous male leadership came to a violent end. For others, like Japan, which banned polygamy in 1880, the process was more of emulation than capitulation. It is only in the past 100 years or so that the majority of humanity came to live in societies where polygamy was illegal.
The big disadvantage that all polygamous societies face is a simple numbers game.
Consider a society of 200 adults with an even split of 100 men and 100 women. The top 60 wealthiest men each take one wife. Then, of those 60 wealthiest men, the top 25 take a second wife, leaving 35 monogamous marriages. Then the top 10 of those men take a third wife and the top five take a fourth. Now all 100 women have a husband. And of the 60 married men in this society, most (35) are married monogamously. This is a typical distribution of mates for a real-world polygamous society.
But this also leaves 40% of all men unmarried. And it is these unmarried men that are part of polygamy’s undoing. Studies have shown that unmarried men are more likely than married men to commit murder and rape. Another analysis found that the greater the percentage of unmarried men in a population, the greater the rates of rape, murder, assault, theft, and fraud.
Many polygamous societies do manage to find a way to project some of the violence of their unmarried men outwards. But that kind of expansive conquest can only last so long.
The Islamic explorer Ibn Fadlan described a Viking chieftain who had 40 slave girls that “were destined for his bed,” while his 400 warriors were given two slave girls each, in addition to their other wives.
But if Viking chiefs had 40-plus concubines and wives, and his favored warriors had an additional four or five women each as well, then where did that leave the vast majority of Viking men who wanted a mate? It left them on a Viking longship headed towards an Irish village where they could capture a woman and sell her husband off into slavery.
In addition to decreasing both internal and external violence, monogamy also encourages peaceful cooperation within a society. Across cultures, those communities with stronger monogamous bonds and increased parent certainty show more male investment in their children. By channeling male effort from fighting each other for control of as many women as possible, and towards investment in children’s development, a monogamous community can spend more time cooperating and becoming more productive as a unit.
No institution has a better track record of binding people together into a larger successful community than the radical egalitarianism of monogamy.
Thanks in no small part to monogamy, our world today is far more peaceful and prosperous than it was in ancient times or the Viking age. But if humanity has been polygamous for most of written history, then why aren’t we better adapted to either: 1) living without mates (as unmarried men in polygamous societies must do) or 2) not experiencing jealousy when our mate is with another person (as married women, and some men, in polygamous societies or relationships often do)?
The answer is that we lived in monogamous hunter gatherer tribes for hundreds of thousands of years before we learned to settle down and domesticate plants and animals. In contrast, consider that gorillas and chimpanzees are all polygynous. Alpha-male apes maintain harems and actively deny other adult males sexual access to his females. Chimpanzees live in larger groups, so alpha-male chimpanzees must be more coalitional- minded, granting sexual access of females to almost all males in the group with preferred access for his most loyal supporters.
Our human ancestors broke away from all this polygynous mating. Since everyone mates with everyone, male chimpanzees have no idea which offspring are theirs and they make no effort to help female chimpanzees raise them
By forming intense pair bonds, our human ancestors brought men into the caring and provisioning of moms and their children. This extra help gave moms the calorie boost they needed to help their offspring grow larger, calorie-intensive brains. These bigger brains then enabled the unique social learning capabilities that made us what we are today.
In other words, monogamy is a big part of what makes us human. Our more recent polygamous past, which began with the agricultural revolution, was just a short blip on a much larger monogamous timeline.
This brief history of human sexual relations shows us three things: 1) we are hardwired to form monogamous pair bonds; 2) the privileged among us will always try to monopolize more mates; and 3) we can check the privilege of the powerful by enforcing monogamous cultural norms.
It is this last point that brings us to an unfortunately growing movement to undermine our culture’s monogamous norms: polyamory.
Proponents of polyamory are a diverse group with different definitions of what polyamory means to them and what they want to see changed legally and culturally. But to the extent the polyamory movement is coherent, what unites them is a desire to make non-monogamous sexual relationships more socially acceptable.
This is the exact opposite of what our society needs right now.
Polyamory advocates say their movement is all about consent and spreading love. But what little research there is on non-monogamous relationships shows that two-thirds of them are non-consensual. Other research shows that it is the men who most often ask for non-monogamy, and it is women who often feel pressured into either agreeing to it, or tolerating it. Either way, people in both consensual non-monogamous relationships and non-consensual non-monogamous relationships report lower relationship satisfaction than people in monogamous relationships. To the extent polyamory sought to improve people’s lives, it is failing.
The simple fact is no institution has a better track record of binding people together into a larger successful community than the radical egalitarianism of monogamy.
Conn Carroll is a former Senate Communications Director and currently works as a freelance writer in suburban Virginia.