Brain Sex
by Anne Moir and David Jessel

Brain Sex suffers from the habitual vagueness of definition common to social science in its use of the term "aggression." The problem may arise from the scientists' desire to be value free. They don't want to make the moral distinction between assertive behavior that does not violate rights and aggressive acts that do. So they lump the two kinds of behavior under the term "aggression," and thereby make "aggression" a morally neutral and therefore "scientific" term. In doing this they fail to provide useful statistics for moral philosophers or even for ordinary people.

Another fault with Brain Sex is that it attributes to the female brain the advantage over the male brain in moral ability. Yet it, being a science book, doesn't define morality. It is unclear what the authors mean by morality except the evidence of police records. But if morality is an abstract field, men should have the advantage of being better able to figure out how to apply moral principles. The authors seem to confuse morality and conformity to established mores. Women conform to the established norms more than men do. But who thinks up and establishes these norms? Men.

The authors of Brain Sex are unclear about whether the female brain is scattered or focussed in regard to verbal abilities. Sometimes they say women have the advantage because verbal ability is focussed in the front on the left side of the female brain. Other times they say women have the advantage because verbal functions are found in both sides of the female brain. It can't be both ways. Can it?

The Facts of Life
Although some women are taller than the average man, it has been scientifically proven that the average man is taller than the average woman. I knew this at least 25 years ago. This fact is not disputed by anybody and it is OK to say it in mixed company, even in this country. However, the following differences between men and women are not so well known, nor are they welcome in some circles, even though these differences are statistically greater than the 7% difference in height--and so have a greater claim to be called scientific facts.

Women have complained for centuries that men are insensitive. Scientists have now proven it. Women, in general, receive and process much more information from their senses than men do.

Morphological Differences between Male and Female Brains
The cerebral cortex, which covers both halves of the brain and which is where higher thought processes take place, is thicker in men on the right side of the brain and thicker in women on the left.

The corpus callosum, the bundle of fibers that link the left and right halves of the brain and transfer information between the two sides, is larger and contains more connections in women than in men.

In both sexes, the left side of the brain controls the right side of the body and the right side of the brain controls the left side of the body. In men, the left and right sides of the brain specialize in different things. The right side of the male brain processes visual images, spacial relationships, abstract thought, shapes, patterns, and emotions. The left side of the male brain handles verbal and linguistic skills, grammar, spelling, vocabulary, speech, definitions, and concrete practical concepts and details.

In women, both sides of the brain process visual images, spacial relationships, abstract thought, shapes, patterns, emotions, vocabulary, definitions, and concrete practical concepts and details.

The only abilities that are handled exclusively on one side of the female brain are grammar, spelling, and speech, which are handled on the left side. These abilities are more concentrated in the female brain than in the male brain. In the male brain, these abilities are handled in the front and in the back on the left side. In women, these abilities are focused in the front on the left side.

Differences in Performance
Women are better than men at picking up nuances from the tone of voice and from body language. Women have better short-term memory for random information and they have better long-term memory. Women have finer control of their hands and voice. They make better musicians. Men make better composers.

Girls are better than boys at identifying spoken words that contain a particular sound such as the S sound. Boys are better at finding words on a page that include a particular letter such as S.

Girls are better communicators. They learn to speak sooner. (It took Einstein 5 years to speak.) They learn to read sooner. They learn foreign languages more easily. They make fewer mistakes in grammar and spelling.

Boys have a more unconventional vocabulary than girls, but boys outnumber girls 4 to 1 in remedial reading classes. Stuttering and other speech defects occur almost exclusively among boys.

Boys are better than girls at solving mazes and jig-saw puzzles. Boys are better at reading blueprints and maps. Boys are better at chess and mathematics. In solving problems, boys are less distracted by extraneous information.

At ages 14 through 16, the IQ scores of girls level off or drop and the IQ scores of boys soar.

Men are better engineers. Ninety-nine percent of all patents are held by men.

Differences in Behavior, Preferences, and Outlook
Women prefer to deal with practical problems. Men prefer abstract thought. Men make the big decisions for the family, such as whether we should trade with Red China. Women make the little decisions, such as what the family will eat, wear, and do at any particular time.

Women are more concerned with personal relationships and tend to view things less objectively than men. In surveys, women's rating of satisfaction with their marriage depended on how affectionate their husbands had been on the day they answered the questionnaire.

Boys are messier than girls and attach less importance to their personal appearance.

Boys are more active than girls and less willing to sit still in school. Ninety-five percent of children labeled hyperactive are boys.

Men are 5 times more likely to commit murder and 20 times more likely to commit robbery than women.

Sex per se per Sex
Women want a lot of sex with the man they love. Men want a lot of sex with different partners. (When President and Mrs. Coolidge were visiting a farm, Mrs. Coolidge asked how often the rooster copulated each day. "Dozens of times" was the reply. "Please tell that to the President," Mrs. Coolidge requested. When the President was told about the rooster, he asked "Same hen every time?" "Oh no, Mr. President, a different one each time." The President nodded slowly, then said "Tell that to Mrs. Coolidge.")

Women give sex for love. Men give up sex for love.

Celibate women miss the closeness of sex. Celibate men miss sex.

Boys become sexually aware earlier and place more value on sex. Women place more value on relationships. Men like pornography and have erotic dreams. Men are more sexually active and promiscuous. Men see women as sex objects. With women, intimacy sometimes leads to sex. With men, sex sometimes leads to intimacy.

Hormones are mind-altering chemicals. Before puberty, boys and girls have the same kinds of hormones at the same levels. After puberty, girls produce more of the female hormones (estrogen and progesterone) and boys produce 20 times as much of the male hormone (testosterone).

Estrogen makes the brain more alert, heightens the senses, gives a sense of well-being, and increases self-esteem, enthusiasm, pleasure, and sexual arousal. But it reduces concentration and makes solving spacial problems harder. Progesterone inhibits pleasure and makes people tired.

Testosterone is the hormone that provides the sex drive in both men and women, and, from puberty on, men have 20 times as much of it in their brains as women have. Testosterone has other effects, which also pertain more to men than to women. It prevents brain fatigue and encourages aggression. Criminals have very high levels of testosterone and so do successful trial lawyers. People with high levels of testosterone are 2.5 times more likely to be poor because of their antisocial behavior. Competition and short bursts of exercise raise the testosterone level. Vigorous exercise over an extended time can burn off testosterone. The best mathematicians are men with moderate levels of testosterone.

The testosterone level in men starts gradually declining at age 50. The levels of estrogen and progesterone start declining rapidly in women between the ages of 45 through 50. They experience mood changes, become irritable and anxious, and suffer headaches, hot flashes, and dizziness. Their bones become more brittle and their skin loses its elasticity.

The gonads produce both male and female hormones. The part of the brain called the hypothalamus acts like a thermostat for the pituitary gland to release hormones.

Testosterone Creates Male Brains
For the first six weeks, the male fetus has the same kind of brain structure as the female fetus. This basic human brain is organized in the female pattern. Then, in the normal case, if the fetus has XY chromosomes, testosterone is produced. This testosterone brings about physical changes in the structure of the developing fetal brain and eventually transforms it into a male brain. The normal female fetus is also exposed to testosterone and her brain also changes, but the female is exposed to a much lower dosage of testosterone and she is exposed to more female hormones, which tend to neutralize the effects of testosterone, so the structure of her brain changes much less. Because the female fetus undergoes much less brain restructuring as it is developing, there is less opportunity for something to go wrong with it. Sexual deviancy is mostly a male problem. Only 1% of females are lesbians. From 4 to 10% of men are homosexuals.

Brain sexing is a matter of degree, depending on how much male hormone the fetus is exposed to. If something interferes with the normal level of testosterone during the months when the brain of the fetus is developing, the fetus may grow up to be abnormal. High stress in mothers lowers the testosterone level in the womb. Two thirds of gay men's mothers had high levels of stress during their pregnancies. Women who were exposed to high levels of male hormone in the womb display little or no maternal behavior. Girls whose mothers took male hormones during pregnancy have higher IQs than other girls and have more success being admitted to college. Boys whose mothers took female hormones as treatment for diabetes do below average in tests of spacial skills. Gay men test lower than straight men but higher than women in spacial skills and higher than straight men but lower than women in verbal skills.

Advice to Teachers

"Nothing is going to change if teachers persist in the illusion that girls are natural mathematicians, whose talents are suppressed by some sort of societal, mathematical machismo ethic, whose influence, by stupendous coincidence, happens to correspond with the ebb and flow of their hormones."

Why are women less affected by strokes?
What is the relationship between left-handedness, homosexuality, and opposite sex brain type?
Is a nymphomaniac a female with a male brain and a female hypothalamus?
Or is she a female with a female brain, female hypothalamus, and a high testosterone level?
At what stage does the hypothalamus develop?
Is it set early in life (in the womb? at puberty?) or can it be modified by hormoned later?
Does it govern the objects of sexual orientation?
What are the ratios between male brain orientation and male sex-object orientation, male brain orientation and female sex object orientation, the hypothalamus and male sex-object and female sex-object orientation, and female brain organization versus all possible combinations of sex-object orientation and the hypothalamus?
Is it subject to the same hormones that influence brain organization?
What is the ratio of male to female babies born to various species of mammals?
Is there any correlation between this ratio and the tendency for one sex or the other to be monogamous?

Many of the more militant feminists probably had too much male hormone when their fetal brains were developing. So they have male-like brains in female bodies. As far as they know, they are normal. So they assume that everybody has a male mind. They conclude that the only reason why the majority of women behave differently than what is natural for these feminists must be that most women have been brainwashed or conditioned by society.

Lesbian lovers who are into serious relationships and commitment may have female organized brains and male hypothalamus. Or they may have male organized brains and male hypothalamus but with low testosterone levels compared to normal men, which would make it easier for them to be domesticated like normal women and civilized men.

Emotions and Emotionalism
Women may be so blinded by how they feel at the moment that they don't see their abiding emotions. Or, in the extreme case, they may have no abiding emotions. Either way, they are not necessarily more emotional than men. The are simply more shallow. Their frequent expressions of emotion are superficial and fleeting. This confuses men. Men think that women are liars or hopelessly flighty. This is a mistake. What women say is often a true expression of what they feel at the moment, but not necessarily a true expression of how they feel about the same circumstances when in a calm state. Women do not have as much ability to be objective about themselves. The female mind is very self-centered. Women take more things personally than are meant to be taken so. Often they cannot grasp the concept that what is being said or done at the moment is not necessarily directed at them. They are by nature half the way to being as paranoid as crack heads.

Sometimes when a woman has her sights fixed on a man she will undermine her own plan if someone, especially her target, says something that she takes the wrong way. She may forget her long-range plan and rebuke the man. Then she has to start over at square one.


"What are little girls made of ... ?
Sugar and spice and all things nice,
And such are little girls made of.

What are little boys made of?
Snips and snails and puppydog tails,
And such are little boys made of."

Year Read: 1992

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