BEFORE WE GO ANY FURTHER, WE SHOULD EXPLORE PERHAPS the most basic question about the relationship between a man and a woman in today’s society: just how suited are we for monogamy?
SLIGHTLY POLYGAMOUS MAN
You don’t need the last chapter to realize that men—and women—cheat in such astonishing numbers that it makes one wonder how any couple manages the feat of staying together. The truth is that monogamy is a highly unusual arrangement in both the animal kingdom and the human world. Ninety percent of animal species are polygamous. For mammals, the trend is even more pronounced—97 percent are polygamous. A look back through time reveals that monogamy is also extremely rare in human societies. In one study of past and present societies for which anthropologists were able to collect data, they found that 980 out of the 1,154 societies allowed men to have more than one wife. That’s almost 85 percent! Of course, that statistic hides the fact that even in polygamous societies, monogamy is the norm. Multiple wives are expensive, and usually only 5 to 10 percent of the men can afford more than one wife, so most of the men are (and were) monogamous whether they wanted to be or not. And polygamy is not just men with multiple wives (known more precisely as polygyny). You can also find a few examples of societies where women have more than one husband (polyandry). This tends to occur in extremely difficult conditions when several men, usually brothers, are needed to produce enough food to raise one child, such as certain societies in Nepal.
But you don’t have to rely on anthropological evidence to see our proclivity for polygamy. Our polygamous past is literally written onto our bodies. To answer the question of just how monogamous we are, we need to make another foray into the world of biology. One fairly good indicator of the extent of polygamy in a species is the size disparity between males and females—the more polygamous a species, the more males must fight to obtain harems. In the battle for dominance, size is usually the decisive factor, with the larger males monopolizing the females. Their size advantage is then passed along to their offspring so that the males continue to grow larger over time (in biological terms, women’s bodies shouldn’t be considered smaller versions of men’s bodies; rather, women are the norm, and men’s bodies should be considered larger versions of women’s bodies). When a species is monogamous, males and females will be similar in size. For gibbons, a monogamous ape species, the males and females are virtually equal in size. For gorillas, whose successful males typically have harems of three to six females, the males are nearly twice the size of females. You can see this in an even more extreme form with the southern elephant seal. On average, the harem size for a male elephant seal is forty-eight females, so the male is enormous compared to the female—fully three tons compared to seven hundred pounds.
How about human beings? Men are roughly 10 percent taller and 20 percent heavier than women, which indicates mild polygamy. Applying a formula developed by biologists, we can estimate that male body size indicates harems of two to three women. But there is some good news. We appear to be evolving in a more monogamous direction. A few hundred thousand years ago, men used to be one and half times the size of females, so our current 20 percent difference represents a distinct decrease. If we give it another couple of hundred thousand years, we may find that men and women match each other exactly and live in perfect monogamous bliss. Of course, this measurement may no longer be as relevant as it once was. Men don’t go around these days competing for women using feats of strength. The competition tends to be mental, rather than physical, which may also account for the shrinking size differential.
. . . AND SLIGHTLY PROMISCUOUS WOMAN
Before women start bemoaning men’s lackluster commitment to monogamy, they should realize that there are also indicators that women are quite likely to stray from monogamy as well. In this instance, the key measurement is testicle size because testicle size and sperm production vary directly in relation to female promiscuity. The reason for this is quite simple—sperm competition. If a female has sex with multiple partners during ovulation, the more sperm a male can ejaculate increases his chances of being the father. Chimpanzees live in large social groups where there is a high degree of promiscuity among the troop—so much so that male chimps can rarely, if ever, be sure of the paternity of a baby chimp. Not surprisingly, chimps have enormous testicles. Gorillas, on the other hand, live in much different circumstances. A male is the only one to mate with his harem as long as he remains unchallenged. Consequently, a gorilla’s testicles are quite small. The comparison between the two species is nothing short of astonishing. Despite being only a quarter the size of gorillas, chimpanzees have testicles that are roughly four times larger. Adjusted for body weight, the disparity is even greater. Biologists have found a similar link between testicle size and mating systems of birds—the largest testicles were found in species where several males fertilize one female.
So just where do human beings fall on this scale? Somewhere in the middle, although closer to the big ball end of the spectrum. Men’s testes weigh in at an average of two and a half ounces. Our testicles are roughly the size of a gorilla’s, even though a gorilla weighs roughly 450 pounds, and the average man weighs only 175 pounds. A chimpanzee’s testicles are almost twice as large as our own, even though a male chimpanzee weighs on average one hundred pounds. To give a rough approximation based on body size, male gorillas’ testicles are only .02 percent of their body weight. Human males are .08 percent, and chimps’ testicles are a whopping .03 percent. Although we fall far short of our chimpanzee cousins, the size of our testes is a clear indication that throughout our history women have typically had more than one simultaneous sexual partner and that sperm competition was a regular part of our past. Of course, the king of balls is not Stephen Colbert but the right whale. The females mate with multiple males, so the males have developed big balls. I’m talking really big balls—each testicle weighs roughly a quarter of a ton.
Again, though, there is some evidence that humans are evolving in a more monogamous direction. Given the size of a man’s testicles, the amount of sperm that he produces is on the lower end of the scale compared to other mammals, which means that our ancestors’ testicles were probably producing a lot more sperm than we are today. This is likely a sign of decreasing sexual competition and stronger pair-bonds. Men also store fewer sperm than other animals, and fully 25 percent of a man’s sperm is defective on average compared to only 5 percent for chimps. When it comes to multiple ejaculations, men are the ninety-eight-pound weaklings of the animal kingdom. A male chimpanzee can ejaculate five times in five hours and still have more than half his sperm stored in his testicles. The mighty and aptly named ram can ejaculate thirty to forty times a day, and each ejaculation contains more than eight times the amount of sperm that the average man produces in one ejaculation (and that’s leaving aside the fact that the man will need a nap before he even thinks about round two, let alone round forty).
On a side note, despite their anxieties, men can be quite proud of how their penises stack up against the primate competition. The average erect penis is a little under six inches with a circumference slightly under five inches (although most studies of male penis size are exaggerated because they rely on self-reported measurements). By comparison, the chimp has an erect penis of three inches. The orangutan measures a measly one and a half inches. And the mighty gorilla weighs in with a tiny one-and-a-quarter-inch penis (if you go outside the primate world, the lowly slug turns out to be the genital giant of our planet—at least in relation to body size—having a penis that is several times longer than its actual body!). Biologists are still arguing about why men have such large penises. It seems that the most likely answer has nothing to do with procreation but is about what is called a “threat display.” In other words, the penis probably once functioned much as a stag’s antlers do—as a visible display of masculinity (at least until pants became widespread).
But to return to the original question, why has our society chosen monogamy when there are so many signs of our tendency toward polygamy? The answer is the same as that discussed in the last chapter: the survival of children. Monogamy becomes more prevalent in an environment where food is scarce, and predators are common. By increasing the bonds between husband and wife, monogamy also increases the certainty of the paternity of the children, which in turn increases the willingness of the father to play a larger role in providing for his family.
MONOGAMY’S WINNERS AND LOSERS
Most women reading this are probably thinking what a good thing it is that polygamy was ditched in favor of monogamy. And there are probably a few men reading this who are feeling nostalgic for a time when men could be men and have as many wives as they could support. But the irony is that monogamy tends to benefit most men and hurt most women. One economist has even called anti-polygamy laws a kind of male cartel undermining women’s bargaining ability. On the other hand, polygamy benefits most women and hurts most men. I realize most women would not consider it a dating triumph to be some man’s second wife. When I say “benefit,” what I mean is how valuable a mate one can attract. You see, it’s all a question of numbers. With polygamy, low-status men are the worst off. They have to struggle to secure any sort of mate. One of the social problems of polygamous societies is the murderous competition that they create among low-status men (incidentally, they also help explain the appeal of suicide bombing to young Muslim men of low status, since part of their promised reward is a harem of seventy-two virgins in the afterlife). Our founding myths are a testament to the struggle to secure the best females. The epic conflict in Homer’s
Iliad
is over the possession of a single woman.
For women, though, polygamy offers them tremendous opportunities to upgrade their spouses. An average-looking woman can settle for an average husband, or she can choose to be the second wife of a high-status man. Women might initially scoff at this idea, but if you presented them with a choice between being Brad Pitt’s second wife or Homer Simpson’s first wife, I think we know which one most of them would choose.
In a monogamous society, though, the competition among women is vastly increased, while the competition among men is significantly lessened. And if the population in a monogamous society shifts slightly so that there are more women than men, the competition between females can become as fierce as any in the animal kingdom. I’m not suggesting that women agitate for a repeal of bigamy laws, but it helps to understand how the rules and values of our society can have unrealized consequences for the competition to secure a mate.
Our sometimes wobbly commitment to monogamy should not be surprising. Notice the way that major institutions—the church and the state to name the big ones—have been mobilized to strengthen the bonds of matrimony. Even so, there are many ways to make end runs around the system. Many people engage in a kind of serial monogamy today, dating or even marrying for a few years and then moving on to the next partner. In effect, this serves as a kind of slow-motion polygamy. Think of the rich and successful men who repeatedly divorce in order to marry younger women. And there are other loopholes, such as adultery.
So, it is important to recognize that monogamy is rife with difficulties for human beings. As one book aptly titled
The Myth of Monogamy
suggests, monogamy is not ordained by natural law but is instead a fragile compromise in the ongoing battle between men and women. No less an authority than Margaret Mead called monogamy the hardest of all human marital arrangements.
3
The Dating Culture
What I Learned About Dating from Thorstein Veblen
A
H, BUT WE ARE NOT SIMPLY THE SUM OF OUR EVOLUTIONARY urges, our concealed ovulations and big balls and deceptive smiles. We are shaped by our rich and complicated cultures. The good news is that cultural evolution occurs much more quickly than genetic evolution, so there is every possibility that our culture could change in a variety of ways that make both dating and relationships easier in the future. In contrast to other species, humans have shown enormous flexibility in their mating arrangements throughout the course of history, which reveals the important and variable role of culture in our lives. In our current case, though, our culture is not doing a lot of favors for people interested in a happy, long-term relationship. In fact, there are very compelling cultural reasons why dating and relationships have become a vexing problem for many of us.
I must warn you that this chapter is somewhat eclectic. It discusses everything from consumerism to demographics. In my defense, I will only say that culture itself is always a bit of a hodgepodge, and any attempt to wrestle with it shouldn’t strive too hard for tidy coherence.
THE CURSE OF COMPARISON SHOPPING
Perhaps no aspect of our culture is more omnipresent and more easily overlooked than consumerism. A significant portion of our time is spent shopping for, buying, or fantasizing about various consumer products. We rarely notice how much it dominates our lives, but it is time to turn a bright light on that forgotten corner. Not only has it caused us distress in general, but I would argue that a consumer mentality has gradually seeped into our approach to dating with disastrous consequences. Our plight could be called the consumer’s dilemma, the unending chase for a slightly better product (or partner) somewhere over the horizon. And you don’t need something as complicated as love to see this. You can find it in a simple and homely jar of jam.