This week Americans honor National Marriage Week, coinciding with Valentine’s Day, the international holiday for lovers. There’ll be lots to celebrate — romance, fidelity, tying the knot and the lifelong commitment that marriage entails.
This year it might also be worth taking special note of the fundamental role that monogamous marriage has played in the creation of peaceful civilizations and even in the evolution of humanity itself.
In my new book, Marriage and Civilization: How Monogamy Made Us Human, I take note of two recent major developments in anthropological and sociological theory:
• Monogamous marriage has played the key roll in creating the relatively peaceful civilizations of Western Europe, India, China and the other Confucian cultures of the Far East. It’s counterpart in marriage arrangements, polygamy, on the other hand, creates cultures that are violent within and without, eternally unstable and at war with other cultures.
• The male-female pair-bond — the foundation of human marriage — stretches all the way back to the beginning of humanity. Anthropologists now believe that we spent the first five million years of our existence — the hunter-gatherer stage — as pair-bonded monogamous couples. Polygamy, common among more recent tribes subsisting on early agriculture, was a backsliding, a later development that produced smaller cultures that are perpetually at war. Only when Ancient Greece, Rome, India, and China re-established monogamy did the larger, more successful civilizations begin to flourish.
Let’s take the last point first. The thing that differentiates humans from our primate cousins — and from all mammals, for that matter — is that we live as monogamous pairs, cheek-by-jowl with other monogamous pairs. No other mammalian species does this. Ninety-five percent of mammals practice polygamy, where a few dominant males monopolize all the females while unattached males are shunted off into the “bachelor herd” where they spend their entire lives competing with each other to break back into the circle of fertile females.
Monogamy makes it possible for large numbers of males and females to work together in close association. This was crucial for the survival of a species that was three feet tall, couldn’t run fast or climb trees, and was pathetically vulnerable to predators. But it wasn’t easy. Anthropologists now believe that the social demands of this arrangement were the main driver in the development of human intelligence.
Yet this intelligence never could have evolved without the two-parent family. Because our brains were growing bigger, we are all born about two months prematurely, since the larger head cannot fit through the birth canal. Even after that, our brains take so long to develop that we are helpless for another two years. This extended period of neural development never could have occurred without two parents providing nurture and protection.
Yet monogamy offered another great payoff as well. It allowed larger numbers of men to cooperate. In a polygamous society, where men can take as many wives as they can want, there are never enough women to go around. This makes the sexual competition much more intense and inevitably leaves some men unmated. With monogamy, on the other hand, there is always “a girl for every boy and a boy for every girl.” Primitive societies resolve this problem by constantly raiding other tribes for women. Where they have been found in their native state — the “fierce” Yanomamo of the jungles of Brazil or uncontacted tribes discovered in the New Guinea highlands in the 1950s — such tribes are constantly at war with each other over women.
The one major religious culture that has retained polygamy into the modern era — Islam — reveals these same characteristics. Because eligible women are scarce, families charge a “brideprice” for giving them up in marriage. Since they are now valuable, women must be veiled and sequestered so they do not squander their worth on casual romance. Men often work into their 30s to acquire the brideprice. Marriages between cousins are arranged to keep wealth in the family. The search for brides pushes men into younger and younger cohorts and marriages between 35-year-old men and pre-pubescent girls become common. And of course this endless search for more women pushes Islamic societies into constant conflict with their neighbors. There are always plenty of women available in the next village or civilization. If you die in the effort, what is the reward? 72 virgins in heaven. What could be more appropriate?
So you see we have lots to celebrate about monogamous marriage this week. Let’s honor it. And let’s try to find a way to stem the adverse trends that are now eroding marriage among sizable portions of the population in American society.