In some ways it is the most basic question of all. Are you are a man or a woman? For centuries, it seemed simple. Men had male sex organs; women had female ones. This did not do a lot for hermaphrodites, who were born with both, but science seemed to solve the impasse by coming up with a sub-atomic rather than surface solution: Men had XY chromosomes; women had XX chromosomes. But in the 1990’s, researchers, including Melbourne’s Andrew Sinclair, in a study of ‘intersex’ people – those with ambiguous genitalia – found a new gene that blew the old certainty out of the water.
Their discovery that a hitherto unknown gene, SRY, was needed to start the process of “maleness” re-launched the gender puzzle. It was now no longer enough to assume that chromosomes defined gender. There was more going on, and while associate professor Sinclair, director of the Royal Children’s Hospital Molecular Development Unit, believes biology will yield the answer, he does have it yet. “This is far from simple,” he says. “We’re just starting to understand what determines gender.”
The problem is finding the indisputable dividing line between male and female. It is not the body, as intersex children make clear. One in 2,000 of all births involve babies with mixed sex anatomy – often sex organs that are ambiguous. Then there are tens of thousands of others with chromosomes that do not comply with the usual XX or XY pattern. Most have normal sex organs and only discover they are different when they try to have children. Are they male or female? The biology does not make it clear.
Melbourne woman Christie North, for instance, who was recently featured on a Four Corners program, was born with male chromosomes and testes. Her condition, known as Androgen Insensitivity Syndrome, means that her body can generate testosterone, but cannot respond to it. She cannot have children or menstruate, and receives annual injections of the female hormone, oestrogen, to help feminise her body.
She looks like a woman, and feels and acts like a woman. But if the everyday formula for gender – XX or XY chromosomes – were applied she would be considered a male. It is confusing. Because her body was unable to process male hormones in the womb, she developed into a female. Hers, as Four Corners explained, is just one of more than a dozen different sorts of intersex conditions that affect thousands of Australians.
Associate professor Sinclair thinks the solution to the gender puzzle may lie in the way testes develop in the embryo. But 15 years after he made his breakthrough with the discovery of the new, key gene in the Y chromosome, he admits it wont’ be easy. “We had a very simplistic notion of a linear pathway, but that is just grossly naïve,” he says. “Fifteen years later we still don’t know how it is regulated.”
A Melbourne colleague, associate professor Vincent Harley, is also investigating the gender question, looking particularly at what the new gene, SRY, might be doing in the brain. Harley, head of Human Molecular Genetics at Melbourne’s Prince Henry’s Institute of Medical Research, wants to understand how the brain may be hard-wired differently for males and females, but doesn’t think distinctive male and female genes will emerge. “It comes down to variations in a whole constellation of genes,” he says “I’m not suggesting there’s one gene for gender, but I do think there’s a biological base for gender identity. There is for everything. Trouble is you will never prove it.”
Both experts are optimistic that a biological answer for gender will emerge, though the recently acknowledged “plasticity” of the brain, that is the way the brain is hard- wired even after birth by environment, does not rule out a role for nurture. “Plasticity is important,” Sinclair says. This does not, however, mean a return to the 1960’s when nurture was seen as critical in deciding the gender of intersex children. Then, spurred on by the ideas of New Zealand psychiatrist, John Money, surgery was used to assign a sex to a child in the belief that “the psychological sex agrees with the haircut.”
Psychology, however, is more complex, than a haircut. It is not just that a number of the children assigned a sex according to the Money doctrine grew up to identify with the opposite gender. It is that sexual desire or preference tends to resist a biological explanation. A decade ago, US researcher, Dean Hamer, claimed to have found a gay gene. If right, it would be have provided a neat genetic marker. But it was wrong, and there are some who now think that attempts to pinpoint a biological origin of sexuality is fraught. Gary Marcus, associate professor of psychology at New York University, has written a book on the subject, and says, “we are starting to see how, in forming the brain, genes make room for the environment’s essential role.” He sees the old nature nurture battle as false, saying that both interact to create the person. The brain, he says, is re-wired, both before and after birth, rather than hard-wired for all time.
Influential author, zoologist, Matt Ridley, agrees. In his new book, Nature via Nurture, he talks of the line between the two being blurred because of the interplay between genes and environment. This is not Andrew Sinclair’s field, but he senses that sexuality is just as much about how you feel as how the brain functions. “It is very early days with this,” he says. Vincent Harley thinks sexual orientation could be like gender identity, with a complex genetic explanation, perhaps interacting with the environment. “There’s stuff going on at both ends, emotions and molecules,” he says.
A more radical view is offered by Dr Dany Nobus, senior lecturer in psychology from Britain’s Brunel University. Nobus, who will address a New Sexualities symposium in Melbourne next week, has spent more than a decade reviewing sexuality, and says no theory of sexuality can ignore the unconscious. Pointing out that being a biological male does not automatically trigger a sense of masculinity, he argues that the body does not determine sexual identity. Nor, he says, does sexual orientation dictates sexual behaviour. “A homosexual man with a strong sense of femininity may have heterosexual fantasies in which he occupies the role of a male chauvinist,” he says.
an intersex child’s gender to remain ambiguous until puberty, when they can decide for themselves, indicates. Sinclair is not so sure. His survey of 50 people who had their sex assigned surgically in childhood found 48 were happy with the decision. But the practise is controversial and part of a minefield opening up around gender that draws on biological detective work to explore the old division between nature and nurture.
Intersex doesn’t always involve blended body parts. An intersex person can look unambiguous sexually, while having mixed sexual although internally their sex anatomy is mixed. This happens, for example, with complete androgen insensitivity syndrome, where a person has some male parts (including a Y chromosome and testes) internally, but is quite clearly feminine on the outside. It’s important to also be clear that intersex is different from transgender in that a person with intersex is born with mixed sex anatomy, where as a person who is transgendered is a person who feels himself or herself to be a gender different than the one he or she was assigned at birth. Some people who are transgendered were born intersexed, but most were born with “standard” male or female anatomy.
