Women and men are different. Not only do we look different, but we act differently and feel differently. This is not a new revelation. But for the last 30 years the differences between the sexes has been attributed to social learning. According to this theory, we really don’t have any sexual identity when we’re born. A child is taught what it means to be female or male, and what we consider feminine behavior or masculine behavior depends on the culture. If a girl was taught that it’s feminine to play with toy guns and do a lot of wrestling, she would, and she’d enjoy it just as much as boys do. The theory says that the differences between the sexes are caused by socialization — by what we learned from parents, teachers, television, and our peers. The theory says we learned what is feminine or masculine, and that’s why women and men tend to behave and feel differently.
As a matter of fact, the socialization theory is so widespread, for many people it isn’t a theory at all, it’s a self-evident truth.
But lately, this “truth” is being shaken by some very solid research from the fields of biology, genetics, neurology and endocrinology. Scientists all over the world are accumulating research data indicating that many of the differences between the sexes are biological and inborn, and some are not much affected by learning.
That’s not to say socialization has no influence. The ability to become socialized — the ability and desire to learn from our own culture — is itself a genetically-created trait, and a powerful one at that. Obviously socialization has an influence. But apparently there are some things out of reach of social learning — some feminine or masculine behavior that cannot be unlearned or overridden.
You might legitimately ask, “What difference does it make? We can see the sexes are different; who cares what the exact cause of it is?”
That’s a good question. Political issues aside, the answer is: It’ll make a difference to you in your relationship with your mate. The differences between the sexes are often a cause of conflict or an underlying source of conflict between a man and a woman.
Most of us believe these differences are learned. And of course, if your mate learned it, your mate can (damn well) unlearn it! Right?
BUT — if some of those differences were produced by your mate’s biology, and you were convinced no amount of effort could change it, guess what? You’d find it easier to accept your mate for what she or he is, and that would have a significant impact on the quality of your relationship.
You may still dislike some of your mate’s characteristics, but you would stop frustrating yourself with unfulfilled expectations. And you would learn to work around them.
Look at it this way: If your mate was nearsighted, and you thought nearsightedness was a learned condition, it might become a point of friction in your relationship. Maybe you’re always on your mate’s back when s/he is driving, for example, because it seems to you s/he is “just not paying attention.”
If you then discovered that the nearsightedness was something your mate was born with and that there wasn’t anything s/he can learn to make it better, here’s what would happen: 1) your expectations would become more realistic (more fitting given the reality), 2) you would be less frustrated, 3) you’d become more forgiving and understanding, 4) you would have less animosity toward your mate, 5) you would start thinking of ways the two of you could work around your situation rather than simply railing against it (maybe buy some spectacles, for example, or you could do more of the driving).
That’s what I want to accomplish with this booklet: I hope to share enough of the enormous amount of research on this subject that your expectations of your mate become more realistic. With more realistic expectations, you can realistically expect to be more satisfied with your mate. Some of the conflict will disappear from your relationship, and you will find new ways of appreciating each other.
As long as you hold out hope that someday your mate will change, you will be frustrated and disappointed. But if you accept that the differences are irreversible (short of surgery or hormone supplementation) you can begin to work with the reality of the situation instead of banging your head against a wall trying to apply the Strictly-Socialization Theory — a theory whose time has come and gone.
In the Beginning
It all begins at conception. The individual sperm cell that enters the egg determines the sex of the fetus. Female sperm carry more information (the information required for the complex processes of pregnancy and birth) and are therefore heavier than sperm carrying male chromosomes. Because it is heavier, a sperm carrying female genes moves slower than a sperm carrying male genes. So sperm carrying male genes get there quicker and are more likely to conceive. 125 boys are conceived for every 100 girls.
This difference, right out of the chute, so to speak, is of course not the result of socialization.
After conception, females mature faster and are born with a 4 to 6 week developmental head-start over males. This has nothing to do with learning or socialization, either. It is a genetic difference.
About one or two months after conception, if the fetus has an XX chromosome, it begins to produce large amounts of estrogen. If the fetus has an XY chromosome, it begins to produce large amounts of testosterone. These hormones organize the development of not only the body, but also the brain.
Later, the hormone levels go way down, but then increase again at puberty, and remain high into adulthood, activating specific “receptor sites” in the brain and body.
A receptor site in a cell is like a button. The only thing that’ll push that button is a specific hormone. For example, there is a molecule very much like testosterone (human male hormone) circulating in the blood of male apes, male birds, male crabs, male fish — just about every male on the planet — and this molecule activates certain behaviors in these animals: strutting, defending territory, displaying plumage, etc.
There are parts of the animal’s brain responsible for each of those behaviors. There are receptor sites in those parts of the brain, activated by the male hormone. All of those male-only behaviors are activated by the same hormone.
For example, among certain kinds of songbirds, the male sings but the female does not sing. Inject the female with testosterone, however, and she begins to sing. The receptor sites in the brain are only activated, in this case, by the male hormone.
If you castrate a male Japanese quail, it will stop copulating and crowing. By castration, you have stopped the production of male hormones. All those receptor-sites stop being activated. Give him an injection of male hormone, and he’s back to crowing and copulating.
Male fiddler crabs normally have one huge claw and one normal sized one. But castrate one while he is young, and his claws are both normal size as an adult, just like a female.
Back near the beginning of the evolution of animals, DNA divided itself into two sexes, and the development of the male and female sex organs were triggered by a testosterone-like molecule and an estrogen-like molecule.
It’s a good adaptation. It’s a clean way to create the necessary differences in the sexes. Over time, more and more adaptations were added to each sex. The two sexes of a single species could now evolve differently, because any adaptation could be triggered by the male or female hormone. So if it produced more offspring to have a wider pelvis in the female, the adaptation could be added and triggered only by estrogen. And if it wasn’t adaptable for males, they could stay as they were.
Human males don’t have claws and we don’t crow. We may strut a little, but not much. We do have testosterone, and women do have estrogen, however. As a fetus, the blood levels of these hormones are up to four times the level they will be in childhood. Why? Because there are basic biological differences being hardwired during the fetus’s development, making the sexes fundamentally and unalterably different for the rest of their lives.
The Human Species
In people, these differences show up in hundreds of different ways. For example, June Reinisch, a developmental psychologist, studied 4,653 infants and found that girls sat up without support earlier than boys, and boys crawl earlier than girls, but then crawl for a longer period of time before they learn to walk. The brains of boys mature more slowly, especially the frontal lobes (responsible, in part, for handling cognitive and social functions).
Keep in mind that these are all averages. Individuals vary wildly. But generalizations can be made and they will be true for most people. You can easily say, without argument from most people, that men are taller than women and that women have less body hair than men. Now of course, there are some women who are taller than some men, and there are some men who have less body hair than some women, but by and large, the differences hold true.
In other words, the generalization is very likely true in your relationship.
It is also generally true that women have better nighttime vision, more flexible joints, and a better oxygen supply to the brain. A woman’s skin bruises more easily than a man’s, and her sweat glands and fat cells are more evenly distributed. She tends to perspire more heavily under her arms, while he perspires more heavily on his chest.
Men have thicker skin, fewer nerve endings on the surface of the skin, a thicker skull, a more slanted forehead and heavier brow ridges (to support larger jaw muscles). Men have tighter joints, better daytime vision and more acute depth perception.
Of course, none of these differences are the result of socialization.
Women have one million fewer red blood cells in each drop of blood than men. Yes, you read that correctly: Take one drop of male blood and one drop of female blood and you’ll find a million more red blood cells in the man’s. A man’s blood also coagulates faster than a woman’s.
We come from a long line of hunter-gatherers, and some of these sex differences must have come about because in all hunter-gatherer societies on record (except for one: the Agta of the Philippines), there is a division of labor by sex. Men did the hunting, women did the gathering.
Some of the earliest sex-difference studies showed that men are better at hitting targets with projectiles than women. And in all the research since then, this has been one of the most consistent findings. Okay, said some researchers, it makes sense that men would be superior at hunting tasks — superiorities like being able to hit a target with a projectile. Fine, they said. Good. But wouldn’t gatherers also develop some superiorities? Like being able to locate berry bushes and tuber patches and nut trees?
So the researchers set up some experiments to find out. In one experiment, a table was piled with objects. A comb, a dishrag, a hammer, a typewriter, a book, etc. — one big jumbled pile of different objects. A man or woman was brought into the room and told to look at the pile for some specified length of time, say, two minutes. Then the man or woman was escorted out of the room. Then the researchers would either remove an object or move it to a different location in the pile.
The subjects were brought back in and asked if the pile looked any different. Sure enough, women are better able to detect a change in location than men. Women have a superior ability to remember the locations of objects.
In fact, women are better at almost all forms of perception: better at hearing small changes in tone of voice and volume, have a better perception of high-sound frequencies, a better ability to distinguish between different tastes, more nerve endings in their skin (and therefore a greater sensitivity to touch), are better at seeing in the dark, and have better peripheral vision.
Men have better depth perception and can see better in bright light. The only auditory superiority men have is in distinguishing animal sounds. A woman’s chances are one in fifty thousand of being color blind; a man has a chance of one in twenty-five.
Estrogen activates the olfactory receptors, and since women have far more estrogen than men, women’s sense of smell is better. Women can detect the scent of musk better than any other odor.
Her estrogen levels vary over the course of a month, and during ovulation, when her estrogen level peaks, she can detect the scent of musk 100 to 1000 times more keenly than during menstruation.
Women notice more. In one experiment, subjects were told the researchers weren’t ready to start yet and asked each one (one at a time) to wait in a small room for a few minutes. Afterward, the subjects were asked what they could recall from the room they were in. That was the whole experiment. The women remembered an incredible (to me, a male) amount of detail. They would say things like, “There was a shelf against the wall crowded with things. There was an open pack of Wriggly’s gum, a book on Greek history, a black sock, a worn out tan colored knapsack, etc.” Rich detail. When they asked the men the same question, they apparently hadn’t paid much attention: “It seems to me there was a shelf in there with some stuff on it. There was a pack of gum...some clothes or something...”
Klassy (my wife) used to tease me about not noticing things, so I was determined to pay attention. One day, feeling victorious, I said, “Hey! You moved that picture. It used to be over here.”
“You’re right,” she said, “I did move the picture...three months ago!”
Men spend more time in shallow sleep as they get older, but aging doesn’t affect women’s sleep as much.
There is an enzyme in the stomach that breaks down alcohol before it reaches the bloodstream. The enzymes in women’s stomachs break down less than one fourth as much alcohol as the enzymes in men’s stomachs, allowing more pure alcohol to enter her bloodstream.
Migraines affect 4 times as many women as men. Women suffer from more aches and pains in general than men. Women feel some sort of discomfort 43% of the time, men 28% of the time. And men find it twice as difficult to tolerate the same amount of chronic pain a woman can tolerate.
Most men put their pants on left leg first; women usually put their pants on right leg first.
According to Dr. Brian Sietsema, the Pronunciation Editor of Merriam-Webster, men and women pronounce the TH sound (as in the word “think”) differently. “Men pronounce it with the tongue slightly behind the upper teeth,” he says, “and women with the tongue between the teeth.”
Men tend to call each other by a word other than the person’s name: dude, man, etc., and women tend to use the person’s name.
Women have better coordination in their fingers. You can tell a woman’s handwriting from a man’s because her's shows more control.
Again, there are variations, but in general each of these differences are likely to be true between you and your mate. Likely. Not absolutely.
During an argument between husband and wife, her blood pressure rises, on average, 6%, whereas his rises 14%. His blood pressure rises more than twice what hers does. Logically, you’d think it’d be just the opposite because she is potentially in more physical danger.
But the differences go beyond logic. They are differences built into our brains and bodies, and the only criteria for the choosing was survival. If a trait survived and had offspring, that particular pattern of DNA went on to have more offspring. If it didn’t have any offspring, it didn’t pass its genes to us. Apparently there was some advantage to having calm women and reactive men. Although those traits may no longer be an advantage, we’re stuck with the biology we’ve got.
Men die sooner or more often in 57 of the 64 major causes of death. In fact, says, Deborah Wingard, an epidemiologist at the University of California, San Diego, “If you look at the top ten or twelve causes of death, every single one kills more men.”
Denying the biological differences between men and women can be dangerous. There’s a drug prescribed for high blood pressure called Propanolol. Recently it has been found that Propanolol is broken down far more slowly in women’s bodies than men’s. Doctors had to lower the dosage for women so they weren’t continually overdosed.
A hormone called DHEAS reduces the risk of heart disease in men and contributes to their longevity. But this hormone had the opposite effect on women (it increases their risk of heart disease).
Twice as many women experience depression than men, and women take 83% of all antidepressants. But the studies on these drugs were done on men. Naturally, if the differences in the sexes are only caused by socialization, then a drug that works for men should work just as well for women. Of course. That’s the politically correct view. But Jean Hamilton, M.D., a researcher from Duke University, found that women’s menstrual cycles affected their reaction to psychotropic drugs (like antidepressants), in some cases causing serious trouble.
For years, doctors told us the warning signs of a heart attack: A dull pain in the center of the chest and/or pain down the left arm. Recent research has found, however, that those are men’s symptoms. Women often experience pain in the back, neck or jaw, or they have nausea, or light-headedness, and often no chest pain. I wonder how many women have had heart attacks because they ignored these symptoms? Assuming that women and men are alike caused deaths.
The sexes are not the same. They react to drugs differently. They show different symptoms. It is not simply a matter of opinion. It is not just a theoretical issue. It is not merely an interesting subject of intellectual debate. An ignorance of the differences can kill a person.
The differences go on and on. And all were created by the hormone that dominated in the womb: estrogen or testosterone.
In women, there are fibers that hold skin to the muscles in parallel cords. This causes the fat in between to bulge, producing what’s called cellulite. In men, the fat is held in place by a dense mesh of fibers, making cellulite much less likely.
Men tend to store body fat around their waist, which produces more cholesterol and triglycerides than storing it in the butt and thighs, where women tend to store most of their fat. One of the reasons men are more susceptible to atherosclerosis and heart disease is the different way they store fat. Fat on the waist is easier to burn. Fat on thighs is more resistant. It’s safety fat. Women who had this fat in times gone by had more babies survive in times of scarcity. Female mammals (including humans) are able to withstand food deprivation for a longer period of time before dying.
A woman’s muscles are less striated, making them weaker but more efficient at burning blood sugar. A man has one and a half times as much muscle and bone as a woman, and half as much fat.
Estrogen affects how much fat a person wants to eat. Humans and other animals have a substance called galanin in their bloodstreams. Galanin produces a desire to eat fat, and makes the fat consumed more likely to be converted to body fat.
Sarah Lebowitz, in her experiments at Rockefeller University, found that if you give a cow an extra shot of galanin, the cow eats more fat. Lebowitz has also found a molecule — called M40 — that blocks the production of galanin. When she administered M40 to animals, they had no taste for fat at all. They ate protein and carbohydrates, but showed no interest in eating fat.
Lebowitz discovered two things that stimulate the human body to produce more galanin. One is the by-products of burning body fat. This makes sense: Your body notices you’ve burned off some fat, and it stimulates your appetite for fat so you can replace what you’ve burned. The other thing that stimulates the production of galanin is estrogen.
Women have more estrogen and more body fat. This is genetic; not subject to change by socialization. We may or may not like it. DNA doesn’t care about our personal, social or political ideals.
A woman has more fat covering her entire body, giving her greater protection against the cold and more buoyancy in the water.
Do you remember the couple who got lost in a snow storm, took the wrong road and ran out of gas? They sat in the car for a day or so and then realized they better find help — no one had driven by in two days.
They got out and started walking. They had no food. They had their infant with them. Finally, they realized they were headed in the wrong direction. They decided that the mother and baby should hole themselves up in a tiny cave and the husband should go back the way they came and find help.
He walked for days and finally found a road and got help. They found his wife and child in good health. Days without food, in freezing weather, and they were fine. The baby was as healthy as could be. Through lactation, using the extra fat on the mother’s body, the baby survived.
Our ancestors went through similar adverse conditions many times: Famines, terrible weather, exposure, epidemics, bad water, you name it. Lots of them didn’t survive. Those whose children survived were our ancestors. Our bodies are the design that can survive extreme conditions.
Some important features that helped those offspring (our ancestors) survive were certain differences between males and females. And those differences are deep and extensive.
At one time differences between the sexes were used to prove that men are the superior sex. Because of this, during the women’s movement it became unfashionable and even rude to discover or point out these differences. But it is impossible to say which sex is superior by studying the differences. Each sex has its own strengths and weaknesses. Neither is “superior.” Being physically bigger is usually better in a wrestling match, but what good does it do if the task is nursing a child or locating a berry bush? Or creating a satisfying relationship with another human being? Or swimming the English Channel?
In 1926 Gertrude Ederle attempted to swim the English Channel, a feat no woman had ever attempted. A writer for a London newspaper was so sure she wouldn’t make it, he wrote an editorial before she started saying that her failure to cross the channel only showed that women should not attempt to enter competitive athletics because they were so obviously physically inferior. But Gertrude Ederle not only made it across the Channel, she broke the existing men’s record by two hours! The world record is still held by a woman. There’s no way men can compete — women have superior biology for the task.
The London paper went to press before the editorial could be withdrawn, and the editor had to eat the crow he completely deserved.
Let’s stop thinking in terms of a superior sex. It’s like asking, “Which is superior, a sponge or a knife?” It depends entirely what you are trying to do. Let’s focus instead on what we can do together. We can share out strengths with each other and as a unit become greater than the sum of our parts.
So far I’ve talked about some of the physical differences between the sexes, because I wanted to give you an idea of how pervasive the differences are. We’re not talking about a few trivial differences in genital structure. Women and men are different to the bone (literally). When you realize that even our red-blood count is different, it becomes easier to accept that some of the more subtle differences might also be built-in and less subject to change than you thought.
Let’s look at one of the more subtle differences now — a difference that can significantly affect your relationship with your mate.
This article was excerpted from the book, What Difference Does it Make? How the Sexes Differ and What You Can Do About It?
Adam Khan is the author of Principles For Personal Growth, Direct Your Mind, and co-author with Klassy Evans of How to Change the Way You Look at Things (in Plain English). Follow his podcast, The Adam Bomb.