Decoding Love Page 8
Because of our built-in preference for attractive people, those who are genetically blessed enjoy all sorts of additional societal advantages beyond simply finding a mate. For instance, one study revealed the power of attractiveness to create personal space. Researchers placed a beautiful woman on a busy street corner and found that people will give her more room than an unattractive woman. And growing up with good looks imbues the person with an inherent self-confidence. In one study, people were made to wait while a psychiatrist conducted a phone conversation. The real purpose of the study was to see how long people would wait before they interrupted. Attractive people waited on average three minutes and twenty seconds. Unattractive people waited nine minutes. And here’s the kicker: when both groups were asked to rate their assertiveness, they gave themselves equal marks! That shows how ingrained these tendencies become and how they are hidden not just from the individuals but from society in general. It turns out that a great deal of what we assume about someone’s personality might largely be the result of something like attractiveness. Female attractiveness even appears to make men behave stupidly. Well, okay, maybe that’s a little harsh, but one study did find that if you show men pictures of beautiful women, the men are more likely to stop thinking about the long-term consequences of their actions. And if they are turned on, watch out. According to another study, men in a state of arousal are more likely to respond positively to almost any suggestion from the merely kinky (do you find women’s shoes erotic?) to the downright disturbing (would you slip a woman a drug to increase the chance that she would have sex with you?).
Your attractiveness also has an effect on the sex of your children. Attractive parents have an increased chance of having a daughter (56 percent, rather than 48 percent). Evolutionary psychologists have speculated that the increase is an evolutionary attempt to maximize the advantages of looks, since those qualities are far more valued in women than men, although they have no idea what the biological mechanism is that causes attractive parents to have more female babies.
WHY YOUNG WOMEN END UP WITH OLD MEN AND NOT VICE VERSA
Up to this point, we have not discussed human personality traits, but there is a great deal of evidence that evolution has shaped these as well. Humor, kindness, empathy—all of them help attract a mate, and all have likely developed at least in part due to sexual selection. The No. 1 task that we have evolved to perform (besides simply staying alive) is to attract a mate and reproduce. Because of this, no aspect of our humanity can be separated from the process of sexual selection. So, it’s not just our intelligence that is a product of evolution. Virtually every aspect of our personality is. The question is, what personal qualities do men and women look for in one another? We’ll explore this topic more closely in chapter 5, but there is an incredibly simple answer to the question.
If you want to boil all this down to its most essential level, men look for youth and beauty in their partners, and women want wealth and status. In one study of personal ads, women mentioned financial success in their ads eleven times more than men did, and men mentioned attractiveness three times more often than women did. To illustrate how strikingly obvious this is, I want you to call to mind one of the many times you have seen a young, attractive woman with a very old but very successful man. For instance, consider 1993 Playmate of the Year Anna Nicole Smith, who was twenty-six when she married eighty-nine-year-old oil billionaire J. Howard Marshall. Not very hard to think of older men-younger women couplings, is it? Now, try to remember the last time you saw the opposite: a young, attractive man with a very old and very successful woman. It’s not so easy to think of examples of that.
In a completely unsurprising confirmation of this observation, studies show that beautiful women end up with rich men far more often than beautiful men end up with rich women. Seeing an older man with a younger woman is commonplace and merely takes to a logical extreme a man’s desire for a young partner and a woman’s desire for a financially successful man, but an older woman with a younger man violates those norms. There is no cultural reason why this should be the case. Our shock can be traced directly to how evolution has shaped us.
Looks are so important to men that, according to one study, the physical attractiveness of a wife is a better indicator of a man’s occupational status than any of her other qualities: better than her intelligence, her socioeconomic status, or her education. Another study has shown that the more attractive an adolescent girl is, the more likely she will marry up (the more sexually active an adolescent girl is, the less likely she will marry up). All of this is not an indication of American shallowness. David Buss has researched thirty-seven cultures around the globe and has found that these preferences show up in every single one of them. In fact, non-Western cultures tend to place an even greater value on female attractiveness because it is a valuable indication of physical health in an environment rife with parasites and other health problems.
Before women judge men too harshly, though, they should recognize that men’s obsession with youthfulness is likely the result of monogamy. Because men are choosing a lifelong partner, there is added pressure to choose someone young who will be fertile for many years. In more promiscuous species, biologists have found that the males exhibit no bias for younger partners. In addition, women have their own set of preferences, which they cling to just as tenaciously. For example, height. Women are nuts about it. Although that seems shallow, especially when the guy can just buy lifts, height is an excellent evolutionary indicator of health. In fact, demographers use height as one measure to judge national health and prosperity. Unfortunately, the national news on this front is not good. The United States once had the tallest and healthiest citizens in the world but now ranks near the bottom of industrialized nations. While other nations have been tacking nearly an inch per decade onto their average (due to things like better access to health care and a more equitable division of wealth), Americans haven’t done so since the 1970s so that northern Europeans now tower an average of three inches over us.
None of this means that men and women don’t value many of the same things. Both sexes, for example, place importance on dependability and stability. But in far more cases than the casual observer may suppose, the sexes are driven by fundamentally different urges.
All of this contains one important lesson for men and women. Hearing women complain about how men prefer younger women or men complain about how women only care about money is probably as old as civilization. Evolution has planted those desires so deeply into us that it’s a waste of energy to fight them. The simple truth is that you are not going to change such fundamental drives, and any change that does occur will happen slowly over many generations. You may wish for men and women to be different, but if you want to succeed in the Darwinian world of dating, you must deal with them as they are.
A Brief Intermission to Consider the Question of Monogamy
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 th
ey 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.