Did you know that every brain begins as a female brain?
Up to eight weeks, every foetal brain looks female; female is nature's default gender setting. If you were to watch a female and a male brain developing via time-lapse photography, you would see their circuit diagrams being laid down according to the blueprint drafted by both genes and sex hormones.
A huge testosterone surge in the eighth week will turn this unisex brain male by killing off some cells in the sex and aggression centres. If the testosterone surge doesn't happen, the female brain continues to grow unperturbed. The foetal girl's brain cells sprout more connections in the communication centres and areas that process emotion.
How does this foetal fork in the road affect us? For one thing, because of her larger communication centre, this girl will grow up to be more talkative than her brother. Men use about 7,000 words per day. Women use about 20,000. For another, it defines our innate biological destiny, colouring the lens through which each of us views and engages the world.
In her book The Female Brain, Louann Brizendine, a neuro-psychiatrist, notes that boys too know how to use this affiliative speech style but research shows they typically don't use it. Instead they'll generally use language to command others, get things done, brag, threaten, ignore a partner's suggestion and override each other's attempts to speak. They are not concerned about the risk of conflict. Competition is part of their make-up.
According to her, the testosterone-formed boy brain simply doesn't look for social connection in the same way a girl brain does. In fact, disorders that inhibit people from picking up on social nuance - called autism spectrum disorders and Asperger's syndrome - are eight times more common in boys. Scientists now believe that the typical male brain, with only one dose of X chromosome (there are two Xs in a girl), gets flooded with testosterone during development and somehow becomes more easily socially handicapped. Extra testosterone in people with these disorders may be killing off some of the brain's circuits for emotional and social sensitivity. In her book, Dr Brizendine says that women have 11 per cent more neurons in the area of the brain devoted to emotion and memory.
Now, no one would dispute that men and women behave in different ways: the question is why? "Are we biologically wired that way or is it due to social conditioning?" There is much evidence that men and women use their brains differently. Women tend to use both hemispheres for language tasks, which may be why girls learn to talk earlier than boys. The right hemisphere, meanwhile, plays a dominant role in the male brain and it is this side that we use to navigate the world and perform spatial tasks.
Sandra Witelson, a professor of psychiatry and neuroscience, who established that Einstein's brain was of average size but uniquely structured, believes that gender shapes the anatomy of male and female brains in separate but equal ways, beginning at birth. When she examined numerous brains, she found that in the female brain the neurons in the cortex were more densely packed. This might explain, she says, why women can demonstrate the same levels of intelligence as men despite having smaller brains.
Some experts, however, believe that the physical differences in the brain may not be there at birth but are gradually sculpted. This is because social conditioning begins from the first day of life, when the brain produces neurons at the rate of half a million a minute. According to experience, neurons and synapses are ruthlessly pruned; a process that continues throughout adolescence. In other words, though something in the brain appears to be biological, it might have come to be that way because of how the body has experienced the world.
Simon Baron-Cohen, professor in the departments of psychiatry and psychology at the University of Cambridge and an expert in autism, firmly believes that the female brain is hard-wired for empathy and the male brain is predominantly hard-wired for understanding and building systems. Indeed he has advanced the theory that autism is the "extreme male brain", not good at understanding other people but very good at systemising. Prof. Baron-Cohen does not claim that all men have male-type brains and all women have female-type brains, just that, on average, more males have systemising brains and more women have empathising brains.
He spent five years writing his book The Essential Difference because he felt it was too "politically sensitive" to complete any earlier. "I would like to believe that, deep down, men's and women's minds do not differ in essence. That would be a very satisfying truth," he says. "Some people say that even looking for sex differences reveals a sexist mind that is looking for ways to perpetuate the historical inequities women have suffered. Fortunately, there are now growing numbers of people, feminists included, who recognise that asking such questions need not lead to the perpetuation of sexual inequalities. In fact, the opposite can be true. It is by acquiring and using knowledge responsibly that sexism can be eliminated."
¤ Prof. Baron-Cohen will be delivering a lecture on the latest developments in autism research on September 4 at 7.30 p.m. at the Intercontinental Hotel. This is a rare opportunity to have one of the topmost experts in the world on how the brain functions answering questions on the subject and on the autistic brain in particular. Attendance is free but by invitation and so anybody interested in attending can send an e-mail to theedenfoundation@maltanet.net or call 9980 4660 at the earliest.