June 21, 1998
Gender Specifics: Why Women Aren't Men
By DORION SAGAN
The Causes and Consequences Go Beyond the Obvious
Western thought about sex -- from the story of Eve to Aristotle's belief that girl babies arise from cooler sperm -- has been tainted by the notion that the female is a kind of imperfect or unfinished male. Medical science, however, has gone from treating women as though they were simply smaller men to realizing that sex confers many more differences than those that are related to reproduction.
In contrast to the feminist premise that women can do anything men can do, science is demonstrating that women can do some things better, that they have many biological and cognitive advantages over men. Then again, there are some things that women don't do as well.
One of the less visible, but theoretically very important differences, is the larger size of the connector in women between the two hemispheres of the brain. This means that women's hemispheres are less specialized: a stroke that damages the left side of the brain leaves men barely capable of speech, while the same damage to a woman's brain is far less debilitating since she can use both sides for language. Although there is no hard evidence, the larger connector may also account for a woman's tendency to exhibit greater intuition (the separate brain halves are more integrated) and a man's generally stronger right-handed throwing skills (controlled by a left hemisphere without distractions).
Mary Catherine Bateson, the cultural anthropologist and a former president of Amherst College, has described women as "peripheral visionaries" able to follow several trains of thought (or children) simultaneously. Men, by contrast, seem more capable of focusing intensely on single topics. Our strengths, then, come from our differences rather than from our similarities.
Science and medicine are finally realizing that the differences that exist between men and women necessitate developing distinct therapeutic treatments addressing the specifics of our physiology. For example, doctors like Dr. Susan G. Kornstein, at the Medical College of Virginia's department of psychiatry, are advocating the use of sex-specific assessment and treatment of psychiatric disorders, like depression.
In a recent paper published in the Journal of Clinical Psychiatry, Dr. Kornstein points out that while depressed men seem to respond best to drugs that affect two neurotransmitter systems, those involving norepinephrine and serotonin, women respond better to drugs that affect only the serotonin system.
These differences in the therapeutic benefits of drugs not only underscore the need for medicine to go beyond giving women tapered doses of whatever is being prescribed for men (a latter-day offshoot of the women-as-incomplete-men theory), but support the idea that men's and women's brains do not function the same way.
Indeed, it is not only our brain functions that apparently diverge, but just about every aspect of our physiology. The way we metabolize alcohol and drugs, the way our circulatory system works and how resistant we are to infection are all affected by our sex.
In utero, girls and boys are chromosomally different; one might wag that the determinant of maleness, the Y chromosome, named for its shape, is "missing" something that the female determinant, the X chromosome, has. But they look identical. The development of characteristic male and female sexual genitalia at birth and of secondary sexual characteristics like breasts during adolescence, result from influxes of hormones, including estrogen and testosterone.
But the hormones we once thought were important only for pregnancy, lactation and sexual drive have profound effects on just about every organ in the body. In fact, the reproductive organs, which from a biologist's perspective are our only reason for existing, control and contribute to everything from mood to how cholesterol is used in the body.
Assigning such an important role to the reproductive organs is not new to our belief system. In ancient Greece, women who were classified as having nervous or "hysterical" disorders were thought to be suffering from an upward dislocation of the womb. Treatment for nervousness and hysteria entailed, among other things, trying to repel the womb back into place by applying noxious-smelling odors to the mouth and nose.
As a few women can testify today, the perception that the reproductive organs caused hysteria later manifested itself in the widespread use of hysterectomies and ovarectomies to treat behavioral disorders among American women during the early part of this century.
Science and medicine have historically used biologically-based sex differences to justify obvious acts of misogyny. It is not surprising, then, that a natural response has been for women to insist on equality implicitly based on the assumption that the sexes are essentially the same.
But women may be just as ill served by a medical profession that treats men and women as equals as by one that follows what Dr. Rudolf Virchow, a famous 19th-century German doctor, believed. (He was the first to describe leukemia and is regarded as the founder of cellular pathology.) As Dr. Virchow put it, "Woman is a pair of ovaries with a human being attached, whereas man is a human being furnished with a pair of testes."
Recent research demonstrates that while men begin to suffer from coronary artery disease earlier in life than women do, women are more likely to die of coronary complications once they are afflicted. Men are also more prone throughout most of their lives to high-blood pressure, but as women get older, this advantage disappears.
The delayed onset of cardiovascular disease in women may be linked to the fact that the female hormone, estrogen, which is produced mostly by the ovaries, protects the circulatory system from disease. Differences in the quantities of estrogen, essential for organization and maintenance of tissues and organs in both sexes, plays an important role in brain development and appears to be the reason that men's brains are bigger, but women's brains have more neurons.
Estrogen makes blood vessels more elastic, stimulates them to expand and allow good blood flow, and prevents cholesterol accumulation on the inside of blood vessels. As women age, however, they lose the protective benefits of estrogen because, in a rather dramatic fashion, their bodies stop producing it.
At the same time, some treatments that are used to prevent cardiovascular disorders -- aspirin, for example -- are less effective in women. Reporting in a recent issue of the International Journal of Fertility and Women's Medicine, Dr. Marianne Legato, of the Columbia University College of Physicians and Surgeons, notes: "Although aspirin use is associated with less frequent myocardial infarction in both men and women, it does not decrease the risk of stroke in hypertensive women, as it does in men."
There are a number of naturally produced compounds that fluctuate more in women than in men: steroids, for example, which are infamous on the street for their simultaneous role in developing muscles and shortening tempers.
It turns out that steroids, a class of compounds that includes sex hormones, may play an important role in the mood swings of menstruators. These hormones directly affect brain cells. The neuroactive steroid allopregnanolone, made from progesterone, dampens the sensitivity of brain cells; it works like benzodiazepine drugs, most familiarly Valium. When the progesterone level is high, a woman is calmer. When it is low, she may feel more anxious and irritable. Moreover, women with PMS become insensitive to the calming effects of Valium-like drugs.
There is a growing consensus that these steroids produced by the sex organs are responsible for the greater incidence of mood disorders and depression in women. And a growing body of research is pointing to a role for other, similar steroids in memory, stress and alcohol abuse.
In keeping with the increasing recognition that some powerful mind-altering substances are internally produced by hormones, it is no wonder that adolescence is often a time of emotional turbulence. You cannot "Just say no" to your body's own genetically timed release of mood-altering sex hormones at puberty.
What society considers "recreational" drug use, which often begins at adolescence, may sometimes be motivated by an effort to self-medicate, changing or reversing the effects of sex hormones and neuroactive steroids. The notorious mood swings of adolescents may very likely reflect the body's adjustment to new concentrations and combinations of these compounds.
Lester Grinspoon, an associate professor of psychiatry at Harvard Medical School and an advocate of the medical use of marijuana, points out that marijuana has long been known as a palliative for the psychophysical pains of menstruation. Queen Victoria, according to her doctor J. R. Reynolds, used it for that purpose. Curiously (and although since disputed), one of the few medical studies on marijuana suggests that its use lowers testosterone levels in men.
Perhaps this drug, among others, interacts with or works in a similar way to the hormonal and neuroactive steroids. In any case women, who are twice as prone as men to depression, and who have a higher body-fat-to-muscle ratio and more hormonally distinct brains, cannot be expected to respond to drugs, legal or illegal, in the same way men do.
The sexual distinction that biology traces to chromosomes and hormones also applies to culture and language. I recall, for example, being put in the girls' group at a day camp as a child because my first name was assumed to be female.
Evolutionists believe that the first sexual reproducers were unisexual cells that became involved in cycles of merging and separating. The first fertilizations probably occurred among starving microbes that cannibalized, but did not completely devour each other, becoming instead two-in-one cells.
Sexual differences evolved gradually over hundreds of millions of years. With these differences came ways of recognizing them. In many species, including humans, the gametes, or sex cells, of the females became fewer, bigger and more sedentary while those of the males became smaller, more fast-moving and numerous. But in humans, while the female sex cells, or ova, are far larger than the male gametes, or sperm, full-grown men are bigger than full-grown women.
The cultural ramifications of body size have been considerable, including the virtual absence of rapes committed by women. They may also have influenced the development of greater female cunning and social acumen to mitigate four million years of male bullying.
In our patrilineal culture, the family name is usually that of the man. Biology tells a more matrilineal story: the tiny DNA-containing oxygen-using inclusions in all of our cells, called mitochondria, come solely from our mothers. Nonetheless, culture remains, for lack of a better term, male-dominated. The French psychoanalyst Jacques Lacan even argued that all speech is part of the "symbolic order" -- the largely negative, male realm of language and rules that supplants the original affirmative closeness of mother and child.
The psychologist Theodore Roszak, who has been exploring what he calls the "twisted sexual politics of modern science," argues that science insidiously reinforces a partial male perspective. "Hard" sciences, like physics and chemistry, Mr. Roszak contends, are venerated, while "softer" sciences, like anthropology and psychology, are disparaged.
"Macho science," he argues, leads to bizarre fictions like selfish genes and cannibal galaxies. Female perspectives, he says, offer science new balance and openness.
From sex among equal single cells to male feminists offering cultural critiques of science's rhetoric, we have learned that the two sexes, subtly different, develop differently, respond differently to certain drugs and see the world in different ways. As the French say, vive la différence.
By Constanza Villalba
Dorion Sagan is the co-author, with Lynn Margulis, of "What Is Sex?" and "Origins of Sex: Four Billion Years of Genetic Recombination."
Constanza Villalba contributed to the research and writing of this article.