Women After All: Sex, Evolution, and the End of Male Supremacy (6 page)

All of these differences and countless more are cultural and historical, contingencies of collective beliefs and experience in particular human settings. Any one of them may change again tomorrow, just like the historical fluctuations in skirt, hair, and beard length—at this writing, big fluffy beards are popular in Major League Baseball, a sport that in my youth was conspicuously clean-shaven. We know all this, and it tends to make us think that genes don’t matter, but they do. What has to be specified is where and how they matter. The things just mentioned are among the myriad ways they don’t. But if you have an identical twin with schizophrenia, you unfortunately have about one chance in two of getting it, while your sibling adopted at birth, who grew up in the same environment as you and your identical twin, has less than one chance in a hundred. This leaves ample room for environmental influences—you have a 50 percent chance of
not
matching your identical twin in schizophrenia—but it’s still a huge difference.

It is now clear beyond the shadow of a doubt that for
some
differences between men and women, genetic influence is much higher than for others. Put another way, men and women differ in their genes, and these differences explain a few—just a few—of the gender differences that many of us have attributed to learning. Culture is powerful, but it is not all-powerful.

Let’s try an extension of the game we played before. I’m going to pick a person at random out of an online telephone directory—from any city or town in the world—and download a lot of information about them. Then I’m going to tell you one fact about that person, and you are going to guess whether they are male or female. If you
are right, I will pay you fifty dollars. If you are wrong, you will pay me the same. Or you can decide not to guess and move on to the next candidate. It’s up to you. Don’t forget: I pick the person at random, and only then do I find out the fact in question about the person. No manipulations or tricks.

Suppose we start with something trivial. I tell you the person has a penis. Now, you are smart enough to know that this does not guarantee a right answer, but it comes so close that you would have to be the least betting person on the planet to refuse to guess on this one. You are almost certainly fifty dollars richer.

We pick another name and investigate the new person. I say that this person, growing up, liked to play with dolls and now likes to wear dresses to parties. Well, you’re not quite as certain as you were last time, but you’ve got a new fifty-dollar bill in hand, and the chances are still overwhelmingly in your favor. Take a shot. Now you probably have a hundred dollars.

I pick a third person and tell you that when they have sex, they greatly prefer or insist that it be with a man. This time, you are actually taking a significant risk—say, 5 percent or so. But with a 95 percent chance of guessing right, what will you do?

You are starting to like this game. The fourth random person, I inform you, has attention-deficit/hyperactivity disorder. The fifth has been arrested three times for assault. The sixth, heterosexual, has been physically abused by a romantic partner. The seventh is often depressed and has attempted suicide four times without success. The eighth pays regularly for commercial sex. The ninth has never masturbated to orgasm. The tenth likes games or sports that involve violence.

Now, not a single one of these bets is a sure thing. But the game is going on and on, and you would be an utter fool not to guess on every question I have asked so far, since you are very likely to get them right. The people numbered four through ten are overwhelmingly likely to be male, male, female, female, male, female, and male.
In the long run, with these odds, even though you will not win every time, you are going to be a very happy gamer.

Of course, I could tell you other facts. I could say the person speaks Mandarin, or is shy, or likes watching television, or is overweight, or has a pet, or is married. You could guess if you like, and probably in the long run you’d break even with these sorts of questions, but you might as well pass and wait for a fact that
statistically, to a very large extent, throughout the world, distinguishes women from men
. Such facts can meet that standard only because culture does not easily contravene them; they arise in large part from genetic differences between the sexes and unfold through hormonal influences on the brain, beginning before birth.

Consider the power of culture in its natural domain. If a visitor to a foreign land points to what we call a dog and looks quizzical, a helpful native might say
chien, perro, hund, kalb, kelev, gou, kutta,
or any one of thousands of other words that mean the same thing and are arbitrarily arrived at through cultural tradition. The possibilities are infinite, and if the world went on long enough, the variations would be infinite, too.

But if the same visitor asks a knowledgeable person, “By the way, are the homicides in your country committed mainly by women?” there are only three likely answers: yes, no, and about the same as men. If culture determined the answer and men and women were not fundamentally different in physical violence, you would expect experts in a lot of the countries to say “about the same” and for the remainder of people to be about equally divided between “yes” and “no.” But the fact is that you will never, ever, anywhere get an answer to that question other than “no.” Of course, it may be elaborated upon, as in:
No, you idiot. What kind of question is that? Men overwhelmingly commit the violent crimes everywhere. This is one of the few rock-solid truths of criminology.
And so on.

In fact, in the game we played before, I could pick a name at random from a list of all the adults in a given country, then pick from a
different country each successive time. If we travel the world, visiting every country, and you play the same way, with that same list of questions, you will occasionally give back fifty dollars, but in the end you will be rich.

There is nothing in human behavior that isn’t variable. Some women are very violent and kill other women or men, although some of the men they kill attack or threaten them first. Women evolved to defend their young, and some of the violence done by women or any female mammal serves this vital goal. Paradoxically, women do most of the killing of infants and children in home settings, but that is because they are the ones who are with them, and such acts are much more likely when an unrelated male is in the home, involved with the mother. In many cultures where male-on-male violence is the norm, some men want and are assigned female roles. An occasional culture will regularly use women as warriors.

There is also huge variation in total killing. The most violent cultures, as in traditional highland New Guinea, had a thousand times the homicide rate (wartime and peacetime combined) as the least violent, such as England today. We in the United States have around ten times the rate in England. Most importantly (believe it or not), violence has been in a steady historical decline across the world for at least hundreds of years. These differences are of the greatest importance, and they prove again and again the power of culture to channel, suppress, or give free reign to biology. But over this huge range of cross-cultural variation—three orders of magnitude, or a thousand-fold—it remains a robust claim: men do the great majority of killings in every culture.

We will trace the consequences of this simple fact for the complexities of history and politics around the world, but before we do we need to turn to Darwin’s theory and the realities it predicts and explains.

Chapter 2

♦

Hidden in Darkness

W
hatever your gender psychology, certain core aspects of it do not result from your upbringing. Basic gender identity, romantic and sexual orientation, and the tendency to violence are aspects of being male or female (or some blend or middle state) that are strongly shaped by genes, hormones, and the brain. But where did this biology come from in the long course of evolution? It is not just psychology or even neuroscience we are after but the evolutionary background to sex and gender, maleness and femaleness. This will take us far afield, to creatures and societies of the present and the past that will help us understand where our gender biology and psychology came from. We are one species in a vast array of sexual beings, and while we express a particular version of the common themes of sex and gender, it is not the only one. Yet to understand our own foibles, we need to look at other worlds. In particular, we need to figure out where males came from, why they are the way they are, whether they are really necessary, and how they can be better managed if (as is likely) women decide to keep them around.

Let’s say you are a female Komodo dragon. Quite a stretch, I know, but let’s just say. You are a giant lizard, roughly the size of a small woman, living in a grassy, sandy spot near an Indonesian forest, where a deer or a water buffalo can wander close enough for you to catch its scent on the wind. You rush to it and bite its leg, injecting highly poisonous venom (and, according to some, perhaps also infecting it with bacteria—we all have to make a living), then patiently wait to feast on the hapless beast when it succumbs in a few days. You live in a world of smells, which you pick up on any passing breeze, tasting the odors with the forked tip of your tongue. A devilish device, perhaps, but you have a very small brain, so you don’t get the irony, and you certainly don’t feel guilty.

Overheated after hunting and eating your huge meal, you need a nap in the shade, where you stay the rest of the day and the next. On the third or some other day, something deep inside suggests to your simple brain your need to reproduce, and it tells your tongue to be on the smell-out for a different aroma: maleness. If you stay receptive, you may gain a curt courtship, a coarse grappling of limbs and tangling tails, a perfunctory positioning of his loins on yours. He’ll pop out one of his penises—he has a backup, for good measure—and deposit some of his genes in you, with results that will be yours alone thereafter. You may resist, but the big oaf, probably heavier than you, may simply climb on top of you and weigh you down until he’s done. If your body is ready, it’s ready.

But suppose you don’t catch the scent of a male, and no male is around to catch yours. Are you doomed to a lifetime of egglessness, just downing deer after deer? It turns out you are not. Under some conditions, you can double the number of chromosomes in some of your own eggs or fertilize them yourself with the chromosomes in a polar body, a little bud on the egg cell that’s a sort of kid sister from its last cell division. It’s not your species’ usual reproductive routine, but it might enable you and a few other females to colonize a new island without the help—or the hulking intrusion—of males. Of course,
you don’t do any of this consciously, but evolution has prepared you to get the job done.

Now suppose you are reduced in size by a thousand-fold and you are an eight-inch-long whiptail lizard, maybe the desert grassland whiptail or the New Mexico whiptail of the American Southwest. We don’t have to specify that you are female, because in your new species, being all you can be means being female, period. In fact, scientists call you
uniparens
because fathers are nonexistent, even as sperm donors. Females have daughters, as do their daughters, and theirs, with every hatchling growing up to be a generator of eggs and, thus, the sole begetter of the whiptail world to come.

But consider the
tiger
whiptail, dwelling in semiarid grasslands in Arizona, not so different in size, feeding habits, or behavior, except for one big drawback: this species has males, and females
need
them to make babies. Instead of having all daughters, a female tiger whiptail has eggs that hatch about half males, which, reproductively, can do no more than inseminate the real reproducers. Since these tiger whiptails are wasting half their substance, half their productivity, and half their food on non-reproducers, how in earth’s name are they going to compete with a species like yours that is all female?

Darwin said it best more than 150 years ago, in a daringly titled paper on primroses and “their remarkable Sexual Relations”—see, there
is
a way to be daring with primroses—which he read to a scientific society in 1861: “We do not even know in the least the final cause of sexuality; why new beings should be produced by the union of sexual elements, rather than by a process of parthenogenesis. . . . The whole subject is as yet hidden in darkness.”

“Parthenogenesis” is Greek for what you were doing as a New Mexico whiptail—“virgin birth.” The Parthenon was the shrine to Athena, goddess of reason and strategy. Athena stayed a virgin, but she did not reproduce on her own, and she passed on no intelligence to help us understand the huge wastefulness of sex. Sex didn’t figure in her own birth, since she was born out of the head of Zeus, the
father god. But in real parthenogenesis, it’s males you don’t need; female whiptails can send Zeus and his sons packing.

John Maynard Smith, one of Darwin’s greatest heirs, called the problem “the twofold cost of producing males.” You and your sisters among the New Mexico whiptails could double your numbers in each generation while the tiger whiptails in Arizona stand pat. Or put it another way: if a female tiger whiptail were born with a hopeful mutation, being able to reproduce without males, she, her daughters, and her granddaughters would soon run away with all of Arizona’s lizardly opportunities. But sex has even more costs than that: males and females have to find each other, and sexual selection (as we’ll see) can easily yield results that run counter to survival.

Yet sex is everywhere in the world of complex animals—plants too, for that matter—and most female-only species descended from ancestors burdened with males. In fact, it’s increasingly likely that early eukaryotes (pronounced
you-carry-oats
), mere one-celled creatures with their genes enclosed in a nucleus, already had something like males.

So this is the paradox: Why did sex become so firmly established, and why is it rare for species to get rid of it, despite the huge advantage of going solo? This latter part of the question could have implications for us. Is the answer to Darwin’s century-and-a-half-old question even now hidden in darkness?