EXCERPTS FROM BRAIN SEX
BRAIN SEX: The real difference between men and women
by Anne Moir, Ph.D. and David Jessel.
Dell Publishing (paperback), New York, 1992.
Men are different from women. They are equal only in their common membership of the same species, humankind. To maintain that they are the same in aptitude, skill or behaviour is to build a society based on a biological and scientific lie.
The sexes are different because their brains are different. The brain, the chief administrative and emotional organ of life, is differently contructed in men and in women; it processes information in a different way, which results in different perceptions, priorities and behaviour.
In the past ten years there has been an explosion of scientific research into what makes the sexes different. Doctors, scientists, psychologists and sociologists, working apart, have produced a body of findings which, taken together, paints a remarkably consistent picture. And the picture is one of startling sexual asymmetry.
Some researchers have been frankly dismayed at what they have discovered. Some of their findings have been, if not suppressed, at least quietly shelved because of their potential social impact. But it is usually better to act on the basis of what is true, rather than to maintain, with the best will in the world, that what is true has no right to be so.
A hundred years ago, the observation that men were different from women, in a whole range of aptitudes, skills, and abilities, would have been a leaden truism, a statement of the yawningly obvious. Such a remark, uttered today, would evoke very different reactions. Said by a man, it would suggest a certain social ineptitude, a naivete in matters of sexual politics, a sad deficiency in conventional wisdom, or a clumsy attempt to be provacative. A woman venturing such an opinion would be scorned as a traitor to her sex, betraying the hard-fought "victories" of recent decades as women have sought equality of status, opportunity and respect.
Yet the truth is that virtually every professional scientist and researcher into the subject has concluded that the brains of men and women are different. There has seldom been a greater divide between what intelligent, enlightened opinion presumes - that men and women have the same brain - and what science knows - that they do not.
Recent decades have witnessed two contradictory processes: the development of scientific research into the differences between the sexes, and the political denial that such differences exist. These two intellectual currents are, understandably, not on speaking terms. Science knows it dabbles in matters of sexual difference at its risk: at least one researcher into the field of gender differences was refused a grant on the grounds that "this work ought not be done".
At a few hours old girls are more sensitive than boys to touch. Tests between the sexes of tactile sensitivity in the hands and fingers produce differences so striking that sometimes male and female scores do not even overlap, the most sensitive boy feeling less than the least sensitive girl. When it comes to sound, infant females are much less tolerant - one researcher believes that they may "hear" noises as being twice as loud as do males. Baby girls become irritated and anxious about noise, pain or discomfort more readily that baby boys.
Baby girls are more easily comforted by soothing words and singing. Even before they can understand language, girls seem to be better than boys at identifying the emotional content of speech. From the outset of life, girl babies show a greater interest in communicating with other people. One study involves babies of only 2-4 days old. It shows that girls spend almost twice as long maintaining eye contact with a silent adult, and girls also look longer than boys when the adult is talking. The boys' attention span was the same, whether the adult was talking or not - showing a relative bias towards what they could see, rather than what they could hear. From the cradle, baby girls like to gurgle at humans. Most boys are just as talkative, but are equally happy to jabber away at cot toys or looking at abstract geometric designs. Boys are more active and wakeful than girls - the male-wired brain of activity at work.
The female bias towards the personal shows itself in other ways. At four months, most baby girls can distinguish photographs of people they know from photographs of strangers; baby boys cannot."
The brain biases persist and strengthen as children grow up, "seeing" life through that particular filter of the brain which they find easier, and more natural, to use. That bias in girls towards the personal, for instance, shows up in experiments. A group of children was given a rather special sort of sight test. They looked through a contraption rather like a pair of binoculars, which showed the left and right eye two different images at the same time. One was of an object, the other of a person. The children had been shown exactly the same images, but when asked what they had seen gave different replies. Boys reported seeing significantly more things than people, and girls more people than things.
As the months go by, and the child stands upright, the boys tend to show a greater interest than the girls in exploring the corners of their small world. Their greater muscle-mass helps them explore and range further than their sisters, and they make fewer journeys back to the reassuring base-camp of mother. Scientists have devised a test where a barrier is strung across the playroom, separating mother and child. The girls tended to stand at the centre of the barrier and cry; the boys made little safaris to the edge of the obstacle to see if there was a way round it.
[Under the heading "Pre-School"]
The infant sexes differ in the way they play. According to one English study, having said goodbye to their mothers at the school gates (taking an average 92.5 seconds for girls, 36 seconds for boys), boys will wheel off into the playground. There, they will play more vigorously, and occupy a much larger play-space than the girls. In the playschool classroom, the boys will be much more interested in building structures out of blocks, playing with any kind of vehicle - indeed with anything which does something, be it a door handle or an electric switch. Girls will opt for more sedentrary games, and, if they build, will tend to build long, low structures while boys go for toppling height in their creations.
A newcomer to the playgroup - of either sex - will tend to be greeted with friendship and curiosity by the girls; with indifference by the boys. There is irritation if the newcomer follows the boys about; girls will tend to welcome the stranger into their group. By the age of four, boys and girls usually play apart, having instituted their own form of infant sexual segregation. Boys tend not to bother about whether or not they like any particular member of the gang - he's included if he's useful; girls exclude other girls because "they're not nice". Girls accept younger children into the group; boys tend to try to join groups of older children. Girls know and remember the names of their playmates; boys often don't.
Boys will make up stories of zap, pow and villainy. Girls' narratives focus on home, friendship, emotions; the boy will tell the story of the robber, while the girls tell the same tale from the point of view of the victim.
On measurements of various aptitude tests, the differences between the sexes in average scores on these tests can be as much as 25 percent. A difference of as little as 5 percent has been found to have marked impact on the occupations or activities at which men or women will, on average, excel.
The area where the biggest differences have been found lies in what scientists call "spacial ability". That's being able to picture things, their shape, position, geography and proportion, accurately in the mind's eye - all skills that are crucial to the practical ability to work with three-dimensional objects or drawings. One scientist who has reviewed the extensive literature on the subject concludes, "the fact of the male's superiority in spacial ability is not in dispute". It is confirmed by literally hundreds of different scientific studies.
Boys also have the superior hand-eye co-ordination necessary for ball sports. Those same skills mean that they can more easily imagine, alter, and rotate an object in their mind's eye. Boys find it easier than girls to construct block buildings from two-dimensional blueprints, and to assess correctly how the angle of the surface level of water in a jug would change when the jug was tilted to different angles.
This male advantage in seeing patterns and abstract relationships - what could be called general strategic rather than detailed tactical thinking - perhaps explains the male dominance of chess, even in a country like the U.S.S.R, where the game is a national sport played by both sexes. An alternative explanation, more acceptable to those who would deny the biological basis of sex differences, is that women have become so conditioned to the fact of male chess playing superiority that they subconsciously assign themselves lower expectations; but this is a rather wilful rejection of scientific evidence for the sake of maintaining a prejudice.
The better spacial ability of men could certainly help to explain the male superiority in map-reading we noted earlier. Here again, the prejudice of male motorists is confirmed by experiment; girls and boys were each given city street maps and, without rotating the map, asked to describe whether they would be turning left or right at particular intersections as they mentally made their way across town and back. Boys did better. More women than men liked to turn the map round, physically to match the direction in which they are travelling when they are trying to find their way.
While the male brain gives men the edge in dealing with things and theorems, the female brain is organised to respond more sensitively to all sensory stimuli. Women do better than men on tests of verbal ability. Females are equipped to receive a wider range of sensory imformation, to connect and relate that information with greater facility, to place a primacy on personal relationships, and to communicate. Cultural influences may reinforce these strengths, but the advantages are innate.
The differences are apparent in the very first hours after birth. It has been shown that girl babies are much more interested than boys in people and faces; the boys seem just as happy with an object dangled in front of them. Girls say their first words and learn to speak in short sentences earlier than boys and are generally more fluent in their pre-school years. They read earlier, too, and do better in coping with the building blocks of language like grammar, punctuation and spelling. Boys outnumber girls 4:1 in remedial reading classes. Later, women find it easier to master foreign languages, and are more proficient in their own, with better command of grammar and spelling. They are also more fluent: stuttering and other speech defects occur almost exclusively among boys.
Girls and women hear better than men. When the sexes are compared, women show a greater sensitivity to sound. The dripping tap will get the woman out of bed before the man has even woken up. Six times as many girls as boys can sing in tune. They are also more adept in noticing small changes in volume, which goes some way to explaining womens' superior sensitivity to that "tone of voice" which their male partners are so often accused of adopting. Men and women even see some things differently. Women see better in the dark. They are more sensitive to the red end of the spectrum, seeing more red hues there than men, and have a better visual memory. Men see better than women in bright light. Intriguing results also show that men tend to be literally blinkered; they see in a narrow field - mild tunnel vision - with greater concentration on depth. They have a better sense of perspective than women. Women, however, quite literally take in the bigger picture. They have wider peripheral vision, because they have more of the receptor rods and cones in the retina, at the back of the eyeball, to receive a wider arc of visual input.
The differences extend to the other senses. Women react faster, and more acutely, to pain, although their overall resistance to long-term discomfort is greater than men's. In a sample of young adults, females showed "overwhelmingly" greater sensitivity to pressure on the skin on every part of the body. In childhood and maturity, women have a tactile sensitivity so superior to men's that in some tests there is no overlap between the scores of the two sexes; in these, the least sensitive woman is more sensitive than the most sensitive man."
This superority in so many of the senses can be clinically measured - yet it is what accounts for women's almost supernatural "intuition". Women are simply better equipped to notice things to which men are completely blind and deaf. There is no witchcraft in this superior perception - it is extra-sensory only in terms of the blunter, male senses. Women are better at picking up social cues, picking up important nuances of meaning from tones of voice or intensity of expression. Men sometimes become exasperated at a woman's reaction to what they say. They do not realise that women are probably "hearing" much more than what the man himself thinks he is "saying". Women tend to be better judges of character. Older females have a better memory for names and faces, and a greater sensitivity to other people's preferences.
Sex differences have been noted in the comparative memory of men and women. Women can store, for short periods at least, more irrelevant and random information than men; men can only manage the trick when the information is organised in some coherent form, or has specific relevance to them.
The hormones, as we will see, determine the distinct male or female organisation of the brain as it develops in the womb. We share the same sexual identity for only the first few weeks after conception. Thereafter, in the womb, the very structure and pattern of the brain begins to take specifically male or female form. Throughout infant, teenage, and adult life, the way the brain was forged will have, in subtle interplay with the hormones, a fundamental effect on the attitudes, behaviour, and intellectual and emotional functioning of the individual. Most neuroscientists and researchers into the mysteries of the brain are now prepared, like the American neurologist Dr Richard Restak, to make the confident assertion "it seems unrealistic to deny any longer the existence of male and female brain differences. Just as there are physical dissimilarities between male and females . . . there are equally dramatic differences in brain functioning". The way our brains are made effects how how we think, learn, see, feel, smell, communicate, love, make love, fight, succeed, or fail. Undertanding how our brains, and those of others, are made is a matter of no little importance.
Infants are not blank slates, on whom we scrawl instructions for sexually-appropriate behaviour. They are born with male or female minds of their own. They have, quite literally, made up their minds in the womb, safe from the legions of social engineers who impatiently await them.
In the first few weeks in the womb, the tiny foetus isn't noticeably a miniature girl or a miniature boy. It has all the basic equipment, such as vestigal ducts, tracts and so on, to develop as either sex. But as the weeks go by, the genes begin to put the message across. If things go normally, and everything follows the XY blueprint of a boy, the chromosomes will cue the development of the gonads into testes. It's now, at around six weeks, that sexual identity is finally determined - when the male foetus develops the special cells which produce the male hormones or androgens, the main one being testosterone. The hormones instruct the body not to bother with developing a feminine set of sexual equipment, while stimulating the development of embryonic male genitalia.
About the same time, if the baby is female, genetically XX, the reproductive machinery develops along female lines, produces no significant amount of male hormone, and results in a girl baby. Just as the six-week-old foetus wasn't recognisably male or female in appearance, so the embryonic brain takes some time before it begins to acquire a specific sexual identity. If the embryo is genetically female, nothing very drastic happens to the basic pattern of the brain. In broad terms, the natural template of the brain seems to be female. In normal girls it will develop natually along female lines.
In boys it is different. Just as male gender depended on the presence of male hormone, so a radical intervention is needed to change that naturally female brain structure into a male pattern. This literally mind-altering process is the result of the same process that determined those other physical changes - the intervention of the hormones.
Embryonic boy babies are exposed to a collosal dose of male hormone at the critical time when their brains are beginning to take shape. The male hormone levels then are four times the level experienced throughout infancy and boyhood. A vast surge of male hormone occurs at each end of male development: at adolescence, when his sexuality comes on stream, and six weeks after conception, at the moment his brain is beginning to take shape. But, as with the development of the rest of the body, things can go wrong. A male foetus may have enough male hormones to trigger the development of male sex organs, but these may not be able to produce the additional male hormones to push the brain into the male pattern. His brain will "stay" female, so he will be born with a female brain in a male body. In the same way, a female baby may be exposed in the womb to an accidental dose of the male hormone - we'll see later how this can happen - and end up with a male brain in a female body.
The biggest behavioural difference between men and women is the natural, innate aggression of men, which explains to a large degree their historical dominance of the species. Men didn't learn aggression as one of the tactics of the sex war. We do not teach our boy children to be aggressive - indeed, we try vainly to unteach it. Even researchers most hostile to the acknowledgement of sex differences agree that this is a male feature, and one which cannot be explained by social conditioning.
The writer H. H. Monro, "Saki", wrote an instructive little story about a liberal household where the parents sought to suppress their son's natural male aggression by refusing him a set of tin soldiers; instead, they supplied a set of tin civil servants and teachers. All, they felt, was going well, until they sneaked into the playroom and saw that he had set out a battle royal between the regiments of the toy teachers and his model bureaucrats. The child was lucky, in that his parents in the end saw the futility of trying to make him something he wasn't, nor could ever be.