杏吧原创

WHAT HAPPENS if a couple have a baby boy but resolve to raise him as a girl?
It鈥檚 a question you might have asked yourself at some stage in your life,
especially if you鈥檝e ever had kids or are at all curious about the roots of your
own 鈥渕aleness鈥� or 鈥渇emaleness鈥�. But no decent parent would ever carry out such a
drastic experiment in social engineering, would they?

In fact, they would. In the late 1960s, the experiment came true when a
seven-month-old boy was badly injured during a routine circumcision in Canada.
Surgeons eventually decided he鈥檇 be better off as a girl. So by the age of two,
little Bruce had become Brenda, his parents in Winnipeg were raising him as a
girl鈥攁nd psychologists were looking on with rapt fascination. Would the
sex change stick?

It wouldn鈥檛. Even as the experts were hailing the sex change as a triumph,
Brenda was quietly rejecting the dolls and dresses and ribbons in the hair, and
by 14 was calling herself David. Proof that maleness and femaleness are
genetically ingrained? Not quite, because the outcome was different a few years
later, when a second Canadian baby suffered the same type of injury. This time
Jim* was surgically remodelled into Jenny* at the age of seven months, and
although tomboyish as a child, Jenny is still a young woman, bisexual but firmly
convinced that she is female.

*Not real names

So who鈥檚 really in charge of your gender鈥攜our biology or your
upbringing? It鈥檚 a huge question that underpins so many of our thoughts and
worries about who we are and how we ought to raise our children. If a
five-year-old boy takes a shine to wearing his sister鈥檚 clothes or playing with
dolls, should we stamp it out or let him be? Are cross-dressers born or made?
Laddish blokes and sensitive new men we tend to think of as being 鈥渕ade鈥�, while
gay men and women we鈥檙e more likely to believe are 鈥渂orn that way鈥�. But are such
assumptions fair?

As the cases of Jenny and David reveal, science can be a pretty blunt
instrument to go looking for answers with. Indeed, at times it can seem almost
brutal in the way it focuses on all that鈥檚 rare or seemingly aberrant in human
behaviour, turning real men, women, boys and girls into study objects along the
way. Unfortunately, it鈥檚 a freak show mentality that鈥檚 so ingrained it鈥檚
virtually impossible to know what science has to say about human gender without
swallowing a little of it. But when you do, you uncover some surprises.

Where to begin? Overall, psychologists reckon our sexual identities are made
up of three separate components. Think of them as the arrows of three distinct
鈥渟ex compasses鈥�. One arrow shows the direction of your sexual
orientation鈥攇ay, straight or bisexual; the second, your style of
behaviour鈥攍addish woman or homemaker, macho man or new man; while the
third shows the direction of what psychologists call your 鈥渃ore gender
identity鈥�. This is the hardest one to put your finger on, but essentially it鈥檚
that deep-seated inner feeling you have that you are either male or female.

In most of us, the three sex compasses point the same way. But the arrows are
not always so tidily aligned. A gay man might be macho, or he might be feminine.
But he never feels he actually is a woman, any more than a masculine woman feels
she is a man. So where does that intangible inner feeling of maleness or
femaleness come from?

Your body perhaps. It鈥檚 almost impossible not to see your appearance as part
of it. Yet simply having the appropriate genitals is no guarantee you鈥檒l
actually feel like a man or a woman. Plenty of people think of themselves as
women trapped in male bodies. And look at David. Despite his surgically acquired
female body something in his brain seemed to know all along that he was male. As
Milton Diamond, the sexologist from the University of Hawaii-Manoa who traced
David as an adult and revealed the failure of his gender reassignment to the
medical world, puts it: 鈥淭he most powerful sex organ is between the ears not
between the legs.鈥�

But what is it between the ears that makes someone male? One suggestion is a
tiny structure inside the brain鈥檚 hypothalamus with a less than catchy name:
鈥渢he central subdivision of the bed nucleus of the stria terminalis鈥�, or BSTc
for short. Most brain differences between men and women seem to be a simple
extension of the obvious anatomical differences between the sexes: interesting,
but perhaps no more likely to be the root cause of feeling male or female than
your ability to grow a beard or breasts. But this microscopic sliver of grey
matter is different (see 鈥淒onate your brain鈥�).

For a start, the structure is larger in men than in women But then so,
generally, are biceps. What really makes it special is that its size also seems
to vary in transsexuals, men who feel like women and women who feel like men.
Those born female who feel male have the big 鈥渕ale鈥� version, those born male who
feel female have the smaller 鈥渇emale鈥� version. Could the simple size of a scrap
of brain tissue really be the key to human gender, to everything Austin, Eliot
and de Beauvoir ever wrote about?

The jury is still out. But even if the BSTc is the brain鈥檚 compass for gender
identity, that only pushes the question further back, to what controls the
size鈥攁nd hence maleness or femaleness鈥攐f such a structure in the
first place.

Genes perhaps. Well, most genetic females do end up feeling female, while
most genetic males feel male, so inheriting male or female chromosomes must at
the very least predispose your gender arrow to point one way or the other. Yet
these chromosomes are unlikely to carry specialised gender genes that rigidly
fix the direction. Take transsexuality. If it were caused simply by inheriting
the 鈥渨rong鈥� gender genes, it would run strongly in families, which it
诲辞别蝉苍鈥檛.

So what about hormones? After all, oestrogen or testosterone-like substances
course through the veins of every fetus, shaping genitals and brain structures
alike. And David, too, would have got his fair share of masculine hormones
before birth.

There is good evidence that the intangible feeling we have of being male or
female is actually far less susceptible to hormonal influences than either our
sexual orientation or our outward style of behaviour. Take the 1 in 10,000 women
who are exposed to high levels of male hormones before birth. The condition,
known as congenital adrenal hyperplasia, may make them more tomboyish but it
doesn鈥檛 make them feel male. 鈥淎ll of them have a shift towards masculine
behaviours,鈥� says Bill Reiner, a psychiatrist and urological surgeon at the
Johns Hopkins School of Medicine in Maryland, 鈥渁nd the incidence of
homosexuality is definitely statistically increased over the general population.
Some of them are extremely masculine, but they nearly all have female gender
identity, which is fascinating.鈥�

And then of course there is Jenny, firmly committed to womanhood despite her
exposure to the full whack of male hormones as a fetus, and despite being
genetically male. 鈥淭he only explanation is that raising this kid as a girl
resulted in a female gender identity,鈥� says Ken Zucker, Head of the Child and
Adolescent Gender Identity Clinic in Toronto, who worked on Jenny鈥檚 case. And
according to Zucker, that tells us something important about our inner gender
identities. Despite being resistant to hormonal influences, they鈥檙e far more
open to social manipulation than either our sexual orientation or the tendency
to behave in a macho or feminine manner. In other words, a camp straight man may
owe his femininity and heterosexuality largely to his biology鈥攁nd his
maleness largely to his upbringing.

Which isn鈥檛 nearly as topsy-turvy as it seems. Gender awareness, as opposed
to sexual activity, begins astonishingly early in infancy, hitting us just when
we鈥檙e most susceptible to social conditioning. By two, most children can sort
pictures of boys and girls into two groups and will give a consistent answer
when asked which group they belong to. Later on comes the concept of gender
stability, where children realise that they will always be either male or female
and won鈥檛 be changing sex as they grow up. Around the age of six this develops
into a complete understanding of gender constancy鈥攖hat people don鈥檛
actually change gender simply by changing their hair or clothes to make them
look like the opposite sex.

Normally, all this unfolds without much conscious effort. Just as children
instinctively pick up on categories such as chairs and dogs and birds, so they
learn that there are two groups of people, and, again not necessarily
consciously, develop an idea of who they are like and who they are not like.
According to Dean Hamer, a geneticist at the National Cancer Institute near
Washington DC, it all happens so smoothly because our brains are actually
hardwired to do it. We have no choice but to scan the world looking for
differences between the males and females around us, and looking for people we
are like and not like. Ultimately, it鈥檚 about needing to know who to have sex
with, says Hamer, whose ongoing search for genes linked to male homosexuality
has won him fame. This hardwiring might be the reason we build cultures in which
those differences are so important, he thinks. 鈥淚t鈥檚 a self-reinforcing system
that works well as long as you have a standard gender identity鈥攐ne that
agrees with your genetic sex and your body sex.鈥�

But not so well if you don鈥檛 conform. At his clinic in Toronto, Zucker
specialises in treating children who have what鈥檚 controversially known as gender
identity disorder鈥攃hildren like Nathan, the five-year-old who repeatedly
told his parents he hated being a boy, because they were 鈥渦gly and mean鈥�, and
that he wanted a vagina. Or like Heidi, the five-year-old who took to dressing
boyishly, cut her hair and eventually adopted a boy鈥檚 name, all seemingly in
response to her mother constantly airing her anxieties about sexual abuse of
girls. The lives of such children provide some of the most telling, and
disturbing, insights into just how open to social manipulation our gender
identities really are.

Although nobody deliberately sets out to meddle with their gender, such
children often seem to have had traumatic experiences or difficult relationships
with one or both parents. Zucker claims to know of several cases where mothers
who鈥檇 longed for a daughter had difficulty coping with the disappointment of
having a son. The sons sensed the disappointment and began dressing and acting
as girls as if to please their mums.

And once such behaviour begins it can take on a life of its own. The vast
majority of children diagnosed with the disorder eventually grow out of it, but
controversially Zucker and many other clinicians use treatment to speed up the
process. One approach ropes in psychotherapy to help children feel better about
being boys or girls. Another involves rewarding affected children for normal
gender behaviour.

Critics, however, worry that this amounts to turning a certain style of
behaviour into a psychiatric condition just because it鈥檚 not yet socially
acceptable. Perceptions of who needs treatment are demonstrably fickle, they
say. Boys are up to six times as likely to be singled out for treatment than
girls鈥攏ot because the disorder is more common in boys, but because most
parents tend to worry more if a son takes to wearing dresses than if a tomboy
daughter develops a passion for toy trucks.

A more sinister issue has also been troubling both the critics and the
clinicians who treat childhood gender identity disorder鈥攖he prospect of
parents demanding treatment for their children, thinking it will ward off
homosexuality.

As yet, there鈥檚 no evidence that treating gender identity disorder influences
sexual preferences later in life. But critics fear that meddling with gender
identities takes us perilously close to engineering sexuality. And in truth,
some studies have found that children diagnosed with gender identity disorder
are more likely to become homosexual later in life.

A few years ago, for instance, Richard Green, a psychiatrist based at Charing
Cross Hospital in London, found that as many as 75 to 80 per cent of boys who
tended to play in a feminine way were homosexual or bisexual later in life. And
at least one mainstream explanation of sexuality ascribes a central role to
gender behaviour early in life.

In a theory known as 鈥渢he exotic becomes erotic鈥�, Daryl Bem, a psychologist
at Cornell University in Ithaca, New York, suggests that we aren鈥檛 actually born
with a sexual orientation as such but a style of behaviour that pigeonholes us
into narrow cultural definitions of maleness and femaleness. Little boys drawn,
for whatever reason, to feminine things tend to spend time with girls, because
most of the boys they meet don鈥檛 share their interests, while little girls drawn
to toy cars and guns spend time with boys. Gradually, members of their own sex
appear remote and exotic until eventually they spark fascination and ultimately
erotic interest.

And it鈥檚 all these potential links with sexual orientation that in recent
years have made the question of whether, and when, to step in to manipulate
gender identity such a hot issue, dividing doctors and gay rights activists
alike. In San Francisco, human rights officials have even gone as far as passing
a resolution condemning 鈥渁ny treatment designed to manipulate a young
辫别谤蝉辞苍鈥檚鈥�g别苍诲别谤鈥�i诲别苍迟颈迟测鈥�.

Passions run high. What nobody disagrees about, though, is that early
upbringing can have some bearing on gender development, and may even tip the
balance. And it鈥檚 this that offers the simplest explanation of the difference
between David and Jenny鈥檚 outcomes. Whereas Jenny got her new gender at the age
of seven months, Bruce鈥檚 operation didn鈥檛 happen until he was nearly two.
Perhaps by then he had already soaked up the basics of boyhood. Perhaps soaking
up the social conditioning on offer to us before we can even speak is how most
of get to feel male or female.

But there are exceptions to every rule and the big exception to this one is
transsexuality. At least some transsexuals behave unusually from a very young
age despite having experienced a completely ordinary upbringing, with many
claiming always to have known they were being raised as the wrong sex. That
flies in the face of both the hormonal theory of gender formation and the theory
of social influence. 鈥淭he transsexual presents a paradox,鈥� says Marc Breedlove,
a psychologist at the University of California in Berkeley. 鈥淭hey鈥檝e got the
hormones of the majority of their genetic sex and they鈥檝e also got at least
nominally the social rearing.鈥� Diamond agrees. 鈥淗ere鈥檚 an individual that鈥檚
brought up in the midst of society, with no anatomical obvious signs, and all of
a sudden Jack wants to become Jill. Where did that come from?鈥�

In labs and psychology clinics across the world, the search continues for
genes, brain structures and environmental factors that might supply further
clues. But in the end perhaps it鈥檚 a doomed quest. Thirty years ago, scientists
were na茂ve or simply arrogant enough to think they had a magic formula for
turning Adam into Eve. Of course it wasn鈥檛 that simple鈥攏othing about human
sexuality or gender identity ever is. So here鈥檚 a radical thought: instead of
forever trying to dissect the lives and biologies of those whose chosen
lifestyles put them in a minority, maybe we鈥檇 all be better off channelling our
energies into celebrating鈥攁nd acknowledging鈥攖he sheer diversity of
our sexual makeups.

鈥淲e thought we could create someone鈥檚 identity,鈥� reflects Reiner. But our
sense of who we are is clearly much deeper than that. 鈥淭he environment shapes us
based on what is already determined, not the other way around. No matter what we
do, people are still the same people, and you can鈥檛 change it. No one can tell
you who you are.鈥�

And maybe that鈥檚 just as well.

If you鈥檙e transsexual, then Dick Swaab wants your brain. Fortunately, he鈥檒l
wait for you to die of natural causes first. At the Netherlands Institute for
Brain Research in Amsterdam, Swaab and his team painstakingly analyse rare
samples of human brain tissue in the hope of finding the key to our
identities.

And a few years ago, their patience paid off. They found a tiny cluster of
brain cells around 0.5 millimetres across that seemed to be linked to our sense
of being male or female. Not only is it larger in men than in women, but it has
a female size in male to female transsexuals, and a male size in the one female
to male transsexual brain they鈥檝e studied.

The difference was in a part of the brain鈥檚 hypothalamus called the 鈥渃entral
subdivision of the bed nucleus of the stria terminalis鈥�, or BSTc for short. More
recently Swaab has managed to show that the male form is not just bigger but
contains more neurons. Could this be the very seat of human maleness and
femaleness鈥攁 sort of gender map in the brain?

The idea is quite plausible. The hypothalamus is well known for its links to
sexual behaviour and hormone regulation, and the BSTc itself has many nerve
connections to the brain鈥檚 amygdala, a region also thought to be connected with
sexual behaviour, emotions, aggression, memory and much more.

The problem is that the size difference only shows up late in
puberty鈥攜ears after we become aware of our gender identity. What鈥檚 more,
the size differences become greater throughout life even though gender identity
differences remain pretty constant. Swaab doesn鈥檛 think it rules out the area.
鈥淚 can imagine that there鈥檚 first a difference in activity of neurons, and then
only later a difference in number,鈥� he says. But it鈥檚 clear this tiny region
isn鈥檛 going to explain everything about our gender identity. 鈥淭his is only the
tip of the iceberg.鈥�

If we look to society for clues to who we are and how we fit into this world
of men and women, what happens when we don鈥檛 see ourselves? I wonder this as I
wait for Claire at the bar. All around me are long legs, short skirts, curvy
figures and made-up faces鈥攜et I鈥檓 the only genetic female in the
place.

Welcome to the final frontier. These days homosexuality is right out of the
closet, and it鈥檚 becoming almost a clich茅 for men to show a feminine side
and for women to be laddish. But really bending gender? That鈥檚 still taboo.

Tonight, with my two X chromosomes, I鈥檓 the oddity feeling that I don鈥檛 fit
in. In the world beyond this bar, the opposite is true. The discomfort of being
different hides the fact that there are many more shades and flavours of gender
than you might think. Birth certificates and passports allow you to be male or
female鈥攂ut never neither or both.

Yet neither-or-both is probably the closest you鈥檒l get to defining Claire鈥檚
gender. 鈥淚 don鈥檛 know if I think like a woman,鈥� she says, 鈥渂ut then I don鈥檛 know
if I think like a man either.鈥� And if Claire is uncertain where her gender fits
in this male-female world of ours, the gender experts are just as confused.

Sexologists (and transgendered people themselves) have invented a bewildering
plethora of labels. 鈥淭ransgendered鈥� is the broadest, covering anyone who doesn鈥檛
conform to the most rigid definitions of male or female, from the teenage boy
rebelliously wearing eyeliner and nail polish to the most committed candidate
for sex change surgery.

鈥淭ranssexual鈥� is more specific. It includes any man who really feels like, or
wants to be, a woman, and any woman who feels like, or wants to be, a man. Many
have surgery鈥攊n the US alone there are up to 40,000 post-operative male to
female transsexuals. But even those who don鈥檛 are quite different from
transvestites鈥攇enetic and anatomical males who cross-dress for fetishist
sexual pleasure. They like the clothes and style, but don鈥檛 necessarily feel
like they want to be women.

Some experts divide male to female transsexuals into two further groups. The
first includes those who develop a female gender identity from childhood. The
second group only start to dress and behave like women at puberty. One theory
calls this 鈥渁utogynephilia鈥�, claiming that the men are attracted to the physical
image of themselves as a woman, to the point where they wish to become that
woman. But these clinical categories seem painfully inadequate to describe the
range of bubbly personalities I meet in the bar.

There are other varieties of gender too. In a spectrum of conditions known as
鈥渋ntersex鈥�, a surprising number of people鈥� up to 1 in 500鈥攁re born
with sex chromosomes at odds with their anatomy. Around one-quarter have some
sort of surgery as infants and deciding which sex to make them can be difficult.
Some experts see transsexualism as a specific type of intersex, where the organ
at odds with the sex chromosomes is, less obviously, the brain.

In other words, list every possible dimension of human sexuality and gender
and then shuffle them into as many combinations as you like. But despite the
diversity, the old rigid categories persist. Many intersexed people would prefer
to be known as just that鈥攊ntersexed鈥攂ut there鈥檚 no sign of this
happening any time soon.

And many transsexuals complain that they are all too often lumped into two
less palatable categories鈥攖hey鈥檙e either fetishists or mentally ill.
Homosexuality, they point out, was scratched from the handbook of psychiatric
illnesses years ago, yet transsexuality is still listed as gender identity
disorder, and the assumption lingers that there鈥檚 an element of distress about
the condition.

That doesn鈥檛 make much sense to Claire. Anatomically and genetically male,
but enjoying her womanly appearance, Claire says she鈥檚 not unhappy with her
identity, only with how people sometimes treat her choice of lifestyle. She
doesn鈥檛 want surgery or hormone treatment at the moment and doesn鈥檛 feel trapped
in her male body.

Rigid gender categories leave Claire cold. 鈥淎t the end of the day,鈥� she says,
鈥渢he differences within each of the sexes are far greater than the difference
between the average man and the average woman鈥�. The same is probably true about
the different varieties of transsexuality.

So call me T-girl, she says鈥攆or transgendered girl.

It鈥檚 official: homosexual men are better hung than straight men. How do we
know? Because a couple of years ago two Canadian psychologists鈥攂oth of
them men鈥攖ook the trouble to trawl through the world鈥檚 biggest database of
penis dimensions, controversially amassed over many years by sizing up more than
5000 American men at the famous Kinsey Institute for sex research at the
University of Indiana in Bloomington.

OK, so the difference is a mere 5 per cent in length and circumference, and
even then we鈥檙e talking about a broad-brush statistical correlation. Plenty of
well-hung men in the survey were avowedly heterosexual and nobody is suggesting
that being well-endowed in any way 鈥渕akes鈥� someone homosexual. So what is this
exercise in genital phrenology actually telling us?

Mostly that scientists still have a way to go before they solve the conundrum
of why some people are gay and others straight. After all, you wouldn鈥檛 be
looking at penis length if your other lines of research were delivering Nobel
winning findings. Equally, though, you have to start somewhere and biology
clearly has something to do with sexuality: identical twins are more likely to
share the same sexuality than are normal siblings of the same sex. Looking for
anatomical differences is not as absurd as it seems.

Especially in the organ that really drives our desires鈥攖he brain. Ten
years ago Simon Le Vay, then at the University of California, San Diego, showed
that a group of cells in the hypothalamus was up to three times smaller in gay
than in straight men鈥攁nd about the same size as in women. Could this grain
of neural sand, known as INAH-3, somehow help to lay the foundation for sexual
orientation very early in life?

Perhaps. Then again, maybe its size is a mere side effect of being gay or
straight. Maybe repeated acts of homosexual or heterosexual sex somehow alter
its size gradually. At the University of California at Berkeley, Marc Breedlove
discovered something like this in another rat brain structure called SNB. Male
rats that had engaged in frequent sex had smaller SNBs than animals that
abstained.

Whichever way round it is, hormones are one likely cause of these small brain
differences. In the first few weeks, the fetus is in a feminised state. At
around two months, a wash of testosterone courses through the body and brain of
the male fetus, imprinting both with male characteristics. Maybe this wash helps
to fix sexual orientation. If so, you鈥檇 expect people who are gay to have a
subtly different physical anatomy from heterosexuals.

And according to Breedlove, they do. For example, one subtle effect of the
testosterone wash is to alter the relative lengths of the index finder and ring
finger. In heterosexual women the two fingers are about the same size, while in
men, the index finger is usually shorter. In gay women, Breedlove found that the
index fingers were stubbier, suggesting they had been exposed to higher levels
of male hormones during development.

In gay men, too, there鈥檚 evidence of fetal testosterone leaving a permanent
signature on anatomy. Ironically, homosexual men may be maler than male. Last
year a team from Texas reported that in response to sound, the brains of gay men
light up in a characteristically masculine way, but to an exaggerated
degree.

Then there is that Canadian discovery about penis length. The link between
penis size and hormones is not fully understood, but one theory is that
homosexual men have 鈥渕aler than male鈥� penises because they experience an unusual
ebb and flow of testosterone during fetal development鈥攁n early surge
followed by a swifter than normal decline.

But if hormones drive sexual orientation, what drives hormones? Clearly,
hormone release is programmed into embryonic development, so it might be
possible to find the genes involved. But such work is notoriously difficult. In
1993, Dean Hamer of the National Institutes of Health near Washington DC and his
colleagues famously discovered the so-called 鈥済ay gene鈥濃�攁 region of the X
chromosome called Xq28. Since then, however, little progress has been made in
identifying other genetic links to sexual orientation鈥攁nd even the Xq28
gene has been questioned.

What鈥檚 more, the flow of hormones in the body is influenced by more than just
genes. Stress, diet, physical activity, even pollutants鈥攁ll may affect a
fetus developing within the womb.

And even that paints a far too simplistic picture. Go back to the identical
twins mentioned earlier. If they are raised together and one is homosexual, the
other is almost certain to be, right? Wrong. Despite the twins鈥� identical genes
and shared upbringing, the chance of them both being gay is just a shade over
fifty-fifty. High, but not exactly a foregone conclusion. How much hormones,
genetics, brain development鈥攁nd other, unknown factors鈥攕hift that
coin toss is still a mystery. 鈥淲e鈥檒l be pinning down and clarifying what鈥檚
happening for the next thirty years,鈥� says Le Vay.

In the meantime, put away the tape measure, guys. When it comes to sexuality,
size isn鈥檛 everything.