Gender Gap

How Genes and Gender Influence Our Relationships

David P. Barash,Judith Eve Lipton

• Editorial: Routledge
• Año: 2017
• ISBN:
  9781351518079
• Edición: 1
• Categoría: Social Sciences
• Categoría: Sociology

Let's face it, say Barash and Lipton: Males and females, boys and girls, men and women are different. To be sure, these differences are often heightened by distinctions in learning, cultural tradition, and social expectation, but underpinning them all is a fundamental difference that derives from biology. Throughout the natural world, males are those creatures that make sperm; females make eggs. The oft-noticed "gender gap" derives, in turn, from this "gamete gap." In Gender Gap, Barash and Lipton (husband and wife, professor and physician, biologist and psychiatrist) explain the evolutionary aspects of male-female differences.

CHAPTER 1
Differences

THERE IS GRANDEUR in this view of life. . . . Whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.

— Charles Darwin, The Origin of Species

We are here to make sense of sex differences: what they are, how they came to be, why they are important, and what they mean to our everyday lives. All people have sex on the mind, in the brain, and in the body. Whether expressed as a physical experience, an emotional attraction, or gender differences, sex pervades our daily lives. True, people do nonsexual things such as “surf” the Internet, dream up religions and weapons of mass destruction, perform neurosurgery, and write advertising jingles and books about button collecting and computer programming. Sex is not the only thing people think about or do.

But even the Internet, Madison Avenue, and the publishing world, not to mention religion, medicine, and the military, devote prodigious time and space to sex. From the cradle to the grave, whether male or female, heterosexual, homosexual, or bisexual, everyone has sexual experiences of one kind or another. No one is truly asexual: persons with childhood autism still go through puberty, individuals who have been castrated for cultural or medical reasons still have gender identity, and even the avowedly celibate must contend with sexual yearnings.

Very few people, however, are entirely comfortable with sex. Although sexual intercourse itself is something of a learned skill, the relationships leading up to it are even more difficult. Men and women worry about finding a mate, about being attractive to him or her, about having to compete with others seeking the same goal. Courtships go awry; encounters with both opposite-sex and same-sex people are frequently charged with an unaccountable energy, relationships often fall prey to miscommunication and distrust. And so our ability to compete with others, to find and hold mates, and even to function normally is constantly tested, just as all men and women constantly evaluate and reevaluate themselves and one another—not just as people but as men and women.

Moreover, sex—by which we mean not only the act itself but also sex as it applies to gender-specific behaviors—has an impact on almost every aspect of human existence: intellectual abilities, childrearing, propensity for violence. Even those among us who are not obsessed by sex in its more obvious or prurient forms are deeply and almost constantly aware of sex differences as demonstrated by the simple dichotomy of boys and girls, men and women. Is that surprising? After all, from the moment of birth, when the nurse or doctor utters the portentous “It’s a girl” or “It’s a boy,” each of us is unambiguously assigned to one category or the other. When it comes to gender, there is very little “in between.” From the chromosomes in every human cell to the preoccupations of every human life, the world is cleft in two: male and female. “As different,” we sometimes say of two things that are clearly distinct, “as night and day.”

But just as night and day blend seamlessly into each other, there are some ambiguous cases of sex differences, notably transvestites and transsexuals and even a few hermaphrodites. Because they are so spectacularly unusual, exceptional cases of this sort receive disproportionate attention, whether in movies like The Crying Game or Broadway plays such as Victor/Victoria. But don’t be misled: such gender bending is extremely rare and does not detract from the overwhelming, commonsense fact that sex differences are not only important but real.

Indeed, human beings are probably more aware of the difference between male and female than of any other distinction in the natural or human-made world. We may, on occasion, have a hard time recalling our telephone number or zip code, but anyone capable of communicating can state his or her gender. And although many of us forget— almost instantly—the name of someone we have just met, just as we may also forget the color of his or her eyes, how he or she was dressed, and so forth, we are unlikely to forget whether he or she was a he or a she. Overall, it is difficult to name anything that is more taken for granted than sex differences. Among the more obvious facets of our lives, few things have been analyzed more and yet understood less than what it means to be male or female. To paraphrase Winston Churchill, never have so many been so concerned about something they understand so little.

In our dealings with students, patients, and lecture audiences, we are often asked by women, “Why does my boyfriend want sex more often than I do?” Men ask, “What does my girlfriend mean when she complains that I don’t communicate enough with her?” And everyone asks, “Why are men so often violent?” and “Do women think differently from men?” In fact, Judith’s office is flooded with patients hoping to resolve gender-related conflicts, people whose sexual lives are fraught with difficulty and frustration. There is the mother who is dismayed by how difficult it is to raise nonsexist children: her daughter prefers to play house, and her son insists on playing soldiers even if he has to line up the forks and spoons to do so. There is the upwardly mobile career woman who fears that her growing assertiveness will turn men off; the recently married man who loves his wife but finds himself attracted to sexy co-workers; the lawyer whose husband dismisses his casual extramarital encounters as “no big deal”; the man who assaults his wife when he discovers that she’s been unfaithful. Smart women and men ask why they have selected poor mates and vow to do better next time but haven’t a clue as to how to go about it.

The fact that sexual activity is highly desired despite its difficulty and frustration suggests that sex ranks high among the priorities of our species. Consider how much time human beings spend seeking the ideal mate, holding on to tumultuous relationships, and grooming their bodies to appeal to the opposite sex—not to mention the emotional and physical energy invested in courtships that go awry or the anguish suffered as a result of miscommunication with one’s partner. And who has not felt the pain of rejection? Yet most of us pick up and carry on, determined to continue the quest for a satisfying sexual relationship.

Our goal in writing this book is not to tell our readers how to have better sex lives, more successful courtships, or sharper communication skills—at least, not in so many words. Rather, we intend to examine fundamental distinctions between males and females and to suggest a unifying biological basis for those differences, thus helping to demystify an important part of our universe and ourselves.

Because sex-specific behaviors are expressed by the simplest life-forms as well as the most sophisticated, we talk a lot about animals on these pages—not only the birds and the bees but also elephant seals, hyenas, lions, worms, and fishes. We do so in graphic detail because we believe that by closely examining the sexuality of other species we can learn a lot about our own behavior: in particular, why we do the things we do.

In a genuine sense we are all animals, genetically connected to one another through an ancient lineage of species, an intricate web that extends back to the primordial ooze from which life sprang almost 4 billion years ago. Since the birth of the earliest cells, evolution has organized the fabric of life, weaving together nature’s warp and woof into a remarkably graceful pattern of history, hardware, and happenstance. Like atomic theory, which provides a unifying basis for understanding chemistry, physics, and biology, evolutionary theory provides a unifying basis for understanding the profusion of life on earth, from paramecia to people. Not only do we physically share our planet with a buzzing, blooming profusion of living things, but we are also genetically linked to our fellow inhabitants, connected to them through an ancient and intricate evolutionary past. Biology looms large in this book because it looms large in all living organisms. As University of Texas psychologist Delbert Thiessen put it, “We do not walk through nature; nature walks through us.”

Evidence that biology scripts the human species can also be found by looking to the field of anthropology. Just consider the panorama of human cultural diversity in all its wild and woolly manifestations, from New Guinea highlanders to Lapland reindeer herders to Polynesian fishermen to Afghan pastoralists to Manhattan stockbrokers, and it is easy to build a prima facie case for the organizing and underlying role of biology. Among such an incredible variety of cultures, all with vastly different patterns of social learning, technological development, religious tradition, historical background, and so forth, one common thread emerges: the biological nature of Homo sapiens and what it means to be male or female. As we shall see, some societies minimize the difference between the sexes; others—perhaps the majority— exaggerate them. But the differences are never reversed, and thus evidence mounts in favor of a biological common denominator.

Just as ecologists have come to appreciate that all things are connected, evolutionary biologists, too, are starting to recognize previously unsuspected connections between “pure biology,” such as eggs and sperm, and the various complex roles and elaborate social “facts” that make up our daily lives. Gametes and gonads, genes and gender all work together to produce sex differences, not only among human beings but among all living things.

Yet the biological pull on our beings is often overlooked; indeed most people are blissfully unaware of the full extent to which biology affects their lives. One recent study of human sperm count attests to the subtle influence of biology. As part of the experiment, ten sexually active couples were physically separated from their partners for various periods of time (during which they remained celibate) and then reunited. When they resumed their sexual relations, the number of sperm in the ejaculate of each man increased in relation to the length of time since previous intercourse. Such findings are not in themselves surprising: sexual abstention is known to raise sperm levels on resumption of intercourse. But noteworthy is the fact that no such increase occurred in ejaculate obtained through masturbation after identical periods of abstinence.

Apparently, there exists a factor—hidden and previously unrecognized—that results in greater sperm production or transfer during sexual intercourse than when fertilization is not a possibility. Although the mechanism remains unknown, the phenomenon makes evolutionary sense. Why waste sperm (which take energy to produce) when no offspring are in the offing? We cite the foregoing example not because it is overwhelmingly important in itself but because it helps reveal how even Homo sapiens—smartest of all animals—can be influenced by evolutionary pressures without having the slightest idea that anything of the sort is going on.

For those inclined to denounce a biological approach to understanding male-female differences as sexist, we hope to reveal that if anything, sexism comes from culture, not from biology per se. Social learning and cultural traditions can magnify or suppress sex differences in human beings by rewarding certain behaviors and condemning others, as well as by providing models and expectations for ways in which boys and girls ought to behave. But they no more create those basic differences, any more than they create the basic biology of maleness and femaleness. Society is responsible for establishing sexist social roles and expectations (what are traditionally called gender differences). But it is evolution that makes for sex differences, the basic, organic, genetically inspired biological distinctions between women and men.

When we lecture on male-female differences in sexual style and motivation, we are often confronted by members of the audience who triumphantly maintain that we must be wrong. Why? Because they know a man, for example, who is altogether nonaggressive or sexually reticent, or a woman with a killer instinct or whose libido has her chasing every male in town. The generalizations in this book are just that: generalizations. A generalization, by definition, applies to the majority within a population, allowing plenty of room for individual exceptions. It is perfectly true, for example, that men generally weigh more than women. This does not mean that there aren’t some small men and large women; it simply means that at the level of the population, the weight of a randomly chosen man will usually exceed that of a randomly chosen woman.

As we make generalizations throughout this book—about sexual inclinations, parental tendencies, aggressiveness, and so forth—please keep this simple body-weight example in mind. Thus, when we point out that men are more likely than women to become sexually aroused by simple visual images, we are not claiming this to be true without exception. We are not proven wrong simply because some men are indifferent to Playboy centerfolds and some women are turned on by posters of Antonio Banderas. Rather, we are talking about general and widespread tendencies, no different in principle from other male-female distinctions that are universally accepted, such as body weight, vocal range, number of hair follicles, and the like.

We do not intend to be judgmental and have tried to steer clear of declaring certain behaviors good or bad. If, again, men are more aroused than women by nude photographs, does this mean they are more barbaric or primitive, unable to distinguish image from reality, or less loving? Or that women are sexually repressed, inhibited, or otherwise defective? Neither. It simply suggests that natural selection has created different behavioral inclinations.

As with so many difficult questions concerning human beings, it may be impossible to prove absolutely that biology exerts a powerful pull on our personas. But we think this book makes a strong case for that assertion, one that will help our readers to make sense of sex and sex differences and, in the process, to better understand their lives. Furthermore, we hope that the insights we offer into the complexities of human behavior and the evolutionary roots of maleness and femaleness will help increase readers’ sensitivity to their fellow human beings. We aim to assist the reader in acquiring self-knowledge and also to demystify the opposite sex—those crucial others with whom each of us shares so much and yet who are often so infuriatingly and fascinatingly different.

CHAPTER 2
Biological Roots

DESCENDED FROM MONKEYS? My dear, let us hope it isn’t true! But if it is true, let us hope that it doesn’t become widely known!

— wife of the Bishop of Worcester, 1860, on being told of the scandalous work of Charles Darwin

“Biological differences between men and women?” some of our readers might well exclaim today. “Let us hope it isn’t true!” But there is every reason to think that it is true and, furthermore, every reason to suspect that evolution has had a strong hand in producing those differences.

The reader eager to harvest an instant armload of glib, quick-and-easy generalizations about men and women will not find them in this chapter. We do talk a lot about human beings, but we also present a lot of theory as well as factual information about other species. It turns out that the myriad ways in which human beings go about their sexual lives—from courtship to mating to parenting to interacting with those of the same sex— very much mirror what thousands of scientists working for many years have seen in other species.

As an evolutionary biologist and a physician, we are not alone in seeking to enhance human self-understanding by paying careful attention to other living things. Neurophysiologists learn a great deal about human brain function, for example, by studying the oversized nerve cells of the giant squid. Geneticists hone their understanding of DNA by tracking the genetic vagaries of the lowly intestinal bacterium E. coli. Hardly any living things are as far removed behaviorally from human beings as giant squid or intestinal bacteria, and no reputable scientist would argue that we should extrapolate directly from either to Homo sapiens. What we can do, however—and what ethologists, sociobiologists, behavioral ecologists, evolutionary psychologists, call them what you will, have been doing for several decades now—is to look carefully at bacteria, and squid, flycatchers, and elephant seals, as well as anything else that catches the eye and stimulates the mind, in an attempt to discern some of the underlying rules that govern life. Just as biologists have studied other living things to reveal how neurons communicate and how DNA replicates, in this book we shall examine other creatures to see how evolution works to make males and females.

In this chapter, we also grapple with issues most people take for granted, delving into why sex evolved in the first place and why the sexual world is divided into two instead of three, four, or any other number of sexes. Most important, we look at how these events set the stage for male-female differences, differences that are frequently distilled into such quips as “Oh, that’s just like a woman” or “It’s a guy thing.” The rest of the book, in which we consider specific arenas of male-female differences—sex, violence, parenting, childhood, and so forth— builds on the ideas presented here.

The Power of Evolution

Human beings are far from biological automatons. We have free will. We do want what we want, within societal constraints. And yet at the same time, we are influenced by many factors, including our biological heritage. At least in part, we behave as we do—not consciously, but on a deeper, more instinctual level—because some sex-specific behaviors have been rewarded by the forces of evolution. In other words, men tend to behave in certain ways and women in others because in the distant past, their sex-specific behaviors gave them an evolutionary advantage. The process by which distinctive male-female behaviors arose is an important part of evolution by natural selection.

Simply put, evolution favors any genetically determined trait— whether behavioral, structural, physiological, or psychological—that leads to more offspring, who in turn pass on those traits to the next generation. For example, a man who is especially attractive to women is more likely to reproduce than one who is not. Thus, more of his genes are likely to be projected into the future and to become more numerous in succeeding generations. It’s as simple as that. There is no willful agency or grand plan; natural selection is simply the result of fortune, in which the winners are those individuals or genes that are most reproductively successful. (By way of comparison, artificial selection occurs when humans breed plants or animals deliberately to promote various traits, whether the huge size and docile disposition of the St. Bernard or the durability of the standard grocery store tomato.) Either way, the fact that some individuals and their genes do better than others translates into something of importance.

Individuals who produce lots of offspring, who in turn produce lots of offspring, and so on from generation to generation, are said to be more biologically or reproductively “fit” than their competitors. Biological fitness—not to be confused with physical fitness—is measured in terms of reproduction and generations. One way to think about the concept is to compare two couples. A man and woman who produce four children but lose three of them during childhood end up having lower biological fitn...