Stanford Today Edition:May/June, 1997 Section: Features: Woman WWW: Woman


Forget Men Are from Mars, Women Are from Venus.
The Stanford campus is abuzz with the latest research on gender.
Prepare to be surprised.

On the eve of one of the most important events of their lives, Jennifer Azzi, Jenny Thompson, Regina Jacobs and other Stanford athletes had to prove they were women. Using a highly sensitive test, doctors at the Olympic Games last year searched for traces of a Y chromosome to make sure the competitors were not men in disguise.

Since the 1960s, the International Olympic Committee has verified the sex of athletes entering women's events. Over the years, the 13 women who have failed the test have had to develop a sudden illness, injury or another reason to explain their withdrawal. Secure until that moment in their identity as women, they were suddenly thrown into traumatic uncertainty about their sex.

The apparently clear-cut test that undermined these athletic careers belies an increasingly complex understanding of sexual identity. The very science that enables sex testing is demonstrating that simple definitions are no longer biologically sound. An individual's genes, chromosomes, anatomy and psychosocial sex characteristics may not always agree. Try as they might, researchers are having trouble stuffing human biology into two distinct boxes labeled "male" and "female."

"Gender is much more than a biochemical construct," says Andrew Pipe, former president of the Canadian Academy of Sports Medicine and chair of the Canadian Center for Ethics in Sport. "It's bizarre to think you can determine whether someone is male or female based on one of these tests." Recognizing the complexity of gender, many sports organizations have discarded sex tests and inspections. Scholars across a spectrum of disciplines are examining whether the division of gender into two narrowly defined categories makes either biological or social sense - and are striving to invent a new language to provide a more accurate view.

Stanford's unique emphasis on interdisciplinary communication and collaboration, along with its breadth of expertise, is well suited to the job. Specialists from throughout the university have developed policy recommendations on genetic testing and on the ethics and scientific validity of research into behavioral genetics. Now biologists here are hoping that the social sciences can help them separate society's beliefs about sexual identity from the interpretation of physical data. Experts in law, feminism, social history and anthropology are turning to biology to illuminate their own perspectives on sex and gender. Such cross-fertilization will help Stanford unravel natural truth from social stereotype and open up a new understanding of the human body.

In women's studies, "sex" describes biology - the anatomical and physiological characteristics we call male and female. "Gender" signifies the social and cultural overlay that makes a man "masculine" and a woman "feminine." Sex is immutable reality (except by an operation and hormones) and gender is created illusion. Biologists working to learn more about the underpinnings of sex, however, are finding just how little we really know - and that the distinctions between male and female aren't always obvious or stable.

Most people understand biological sex as dictated by a combination of sex chromosomes. If a sperm and an egg bring together two X chromosomes, the baby is a girl. Combine an X and a Y, and it is a boy. There are, however, a small but consistent number of people who don't fit an easy chromosomal definition. People with Turner's syndrome grow up as females - even with only one X chromosome. People with Klinefelter's syndrome have two X chromosomes and one Y, yet become men. There are XX males and XY females whose sex doesn't match their chromosomes. Usually this is explained by the presence or absence of particular genes; sometimes it's because of unusual levels of particular hormones at important developmental stages.

Fertility isn't a good measure, either. Turner's women and Klinefelter's men aren't fertile. Neither are some men who go through normal puberty, then later find they are deficient in an important male hormone called gonadotropin-releasing hormone. Nor are some XY men with small changes in their Y chromosome. Breast tissue, body structure and facial hair, all generally accepted cues, can in fact contradict sexual identity. The Bearded Lady, a performing artist from New York named Jennifer Miller, is just that - a woman with a beard. "To some degree, a person's sex is what they think it is," says Douglas Vollrath, a Stanford geneticist who mapped the Y chromosome in 1992. His work has provided a foundation for further studies on Y, including the recent identification of genes involved in fertility and sperm production located there.

Initially, scientists set aside the X chromosome in their hunt for sex determination. Instead they gave all the credit to a spot on the Y chromosome that seemed to order an embryo to become a male. They named this SRY, for sex-determining region, Y chromosome. But four years after the discovery in 1990 it still wasn't clear exactly what that "master switch" did. Today researchers think it may turn off something on the X chromosome. And the X chromosome, which had been assumed to handle only "housekeeping" functions, has turned out to contain at least two key genes in determining sex.

Now it appears that millions of years ago the X and Y chromosomes were identical. Over time, the transfer of genetic material between them led to specialization of each, and Y became a necessary component for development of a chromosomal male. But the X chromosome, vital to all human life, increasingly is proving itself very active in setting sex.

Research on fruit flies, which share a remarkable number of regulatory genes with humans, has provided valuable information about the X chromosome's operation. Stanford geneticist Bruce Baker and a consortium of researchers from across the United States are hunting for the genes that program fruit fly sex. If the fruit fly embryo has more than one X chromosome, a gene dubbed "sex lethal" starts a cascade of processes that lead to a female central nervous system and female body parts. Two others, "intersex" and "doublesex," work together to develop genitalia, pigmentation and biochemical processes. With just one X chromosome, an alternate pattern leads to male development, and doublesex works on its own to produce a male-specific protein. Variations in any of these genes may lead to a change in the fly's biological sex or sexual behavior.

Some researchers say that the variety of sexual possibilities in both fruit flies and humans stems from the diversity of mechanisms involved. In each, male and female embryos are initially equipped to go either way. A human embryo develops the foundations for both a female set of ovaries and a male set of testes in the first weeks. A molecular chain of events orders one set to disintegrate at about eight weeks. At about nine weeks the embryo starts to develop external genitalia that match the internal sex organs.

At Stanford Medical Center, a baby's genitalia and internal organs aren't consistent with one sex or the other as many as 20 births a year - and doctors do not know whether to announce the arrival of a boy or a girl. Clinicians look first to the internal anatomy, then to the chromosomes for clues. In the most difficult cases, a team of specialists must work together to reach a sex assignment best for the child and to explain to parents that sex identity isn't solely a matter of Xs and Ys. Using hormones and delicate surgery, doctors try to create a sex the child will be able to live with.

After a decade of research, surgeons at Stanford Medical Center can perform complicated reconstructions in just one operation instead of several. Dr. Linda Shortliffe, chief of pediatric urology and chair of the department of urology, can reduce a masculinized girl's clitoris, separate a combined vagina and urethra, and create or reform the vagina. Or she may reconstruct a boy's entire urethra, shifting the opening from below the scrotum to the top of the penis and straightening the penis.

"It is a very complex surgery, especially on these little, little children," Shortliffe says. It's easier and less risky to do the work at about six months when the child is physically more mature, but if the parents are extremely uncomfortable with their baby, Shortliffe will operate within the first couple of weeks of life. "The first question parents hear is, 'Did you have a boy or a girl?' We consider it sort of an emergency, because it is upsetting to parents. You don't want to harm sex bonding," Shortliffe says.

Technology such as ultrasound and chromosome-typing before birth has helped make sex identity seem more obvious, so parents have less tolerance for the unusual, says Dr. Ray Hintz, a Stanford endocrinologist and professor of pediatrics. "It can be difficult to get the family to accept the child as what they are. They can't just go home and throw away those blue curtains and bedspread and get pink."

Hintz says changing attitudes about gender roles and non-heterosexual sexuality hasn't softened the shock that parents feel when they learn their child isn't easily defined as male or female. People may be more open-minded about sex choices, but they still believe it's necessary to be one or the other, he explains. The underlying assumption is that sexual identity is a biological truth to which people can apply social concepts of gender. "It's just too real and too basic a situation for people to deal with things as quickly and as well as possible," Hintz says.

Of course, scientific theories about sex and gender have special power and meaning beyond the classification of bodies. The biology of sex - from chromosomal characteristics to external attributes - forms the foundation for social claims about the proper roles for men and women.

In athletics, for example, presumptions about the capabilities of women's bodies tend to collide with their success on the field, says Alison Carlson, assistant director of the Global and Public Management Programs at the Stanford Graduate School of Business and a leader in the campaign against sex testing in sports. A member of the working group on gender verification for the International Amateur Athletic Federation, Carlson says women athletes have tended to support testing as a response to the bias against successful women athletes. "They welcomed testing as a reaffirmation of their femininity," she says. Carlson has developed a campaign for the Women's Sports Foundation to educate women athletes about sex testing. "Women were buying into the underlying idea that once you get beyond a certain level of strength and agility, you're no longer a woman," she says.

Biology is often used to explain differences in status between men and women, says Deborah Rhode, an expert in gender and the law at Stanford's School of Law. Hormones, brain structure and genes all are called upon to explain why girls are wide-eyed and timid and boys are athletic and destructive. Even evolution comes into play: Natural selection is said to have favored the physical strength and aggression necessary for men to become successful hunters, and the caretaking and social skills of women who were the best gatherers and nurturers. Conventional wisdom has it that men naturally strive for power, while women seek out ambition in their mate.

In her new book, Speaking of Sex, Rhode traces the history of persistent gender inequalities and the ways people use biology to rationalize them. In 1873, the prominent Harvard researcher Edward Clarke argued that higher education led to infertility among women. He linked a decline in birth rates to increased education rates among women to show that the body's zero-sum energy system was at work: The energy expended in an institute of higher learning drained the energy available in the womb. (Such analyses haven't faded away. Last year, the Military College of South Carolina, the Citadel, argued that females were biologically unsuited for its trademark adversarial training and should be kept out.)

Rhode also traces how assumptions about sexual identity have harmed men and women who don't fit gender stereotypes. In 1982, accountant Ann Hopkins was denied a partnership at Price Waterhouse and counseled to "walk more femininely, talk more femininely, dress more femininely" if she wanted a promotion. After seven years she won a sex discrimination suit against her company, but judges admitted later it was a close case. Men who don't fit stereotypical norms have even fewer legal protections: Gender discrimination suits by men fired or not hired because of feminine behavior or dress have not been held up in court.

In prohibiting employers from discriminating against people on the basis of gender stereotypes, the courts have enshrined a binary biological interpretation of sex identity. Employers and schools are not allowed to discriminate against women because of their status as women or against men because they are men. People who fall in between have not been protected.

There are signs, however, that society as a whole is starting to look differently at biological sex, according to historian Estelle Freedman, chair of feminist studies at Stanford and an expert on the history of sexuality. Although sexuality is still considered deeply rooted in biology, reproductive technology is helping to separate sexual expression from reproductive necessity, Freedman says. Churches and community institutions are relinquishing their control over sexual activity, allowing people to develop their own sexuality.

"Sexuality itself has become a variety of choices: heterosexual, homosexual, fetishist," Freedman says. Images of androgeny and mixed sexual orientation are becoming more common in advertising and popular culture. Some younger people are deciding not to choose one particular identity. Whether these changes in sexuality reverberate back into perceptions of gender and biological sex is still unclear, Freedman says.

Acting sex and gender, rather than adhering to the dictates of what is considered biological necessity, may become more of an option. Diane Middlebrook, a Stanford English professor and biographer, describes the possibility in the story of a female jazz musician, Billy Tipton, who performed, married and raised children as a male. Middlebrook says she came to understand Billy Tipton's gender identity as an effect, as something not defined by Tipton's biology, but created. Tipton's life - from adolescence until death - was about manipulating gender identity. "I think of my files on the life of Billy Tipton as a catchment area for investigating contemporary society's deeply held ideas about sex difference," Middlebrook wrote.

Biologist Ellen Porzig, in the Program in Human Biology, has studied the ways society calls on biology to define the masculine and feminine in naturalistic terms and to solve long-standing social issues over what is permitted under those names. Rather than making dualistic gender differences clear, Porzig says that science ultimately will undermine the social categories.

Historically, biases in gender-stereotyping often have clouded the interpretation of biological research. Assumptions about power and submission, authority and passivity permeate a language that describes sperm as active and eggs sleepy; the female embryo as the result of a "default pathway" in sexual development. As science presses forward, new discoveries tend to contradict interpretations of nature that are steeped in social tradition, Porzig says.

The use of biology to support clear-cut sexual dualism is losing its power, replaced by a sense of broad-spectrum diversity. "A lot of this social construction of biology doesn't stand up to rigorous analysis," Porzig says. "Biology is not destiny." ST