News in Science

Debunking the 'gender brain' myth

Brain pseudoscience Pop science is playing up differences between girls' and boys' brains, with potentially damaging consequences in the classroom and beyond, says an Australian cognitive neuroscientist.

Dr Cordelia Fine will present her argument today at the Australian Council for Educational Research Conference in Melbourne on the brain and learning.

"This dialogue about 'boy brains' and 'girl brains' makes us overlook the important point that, although there are average differences, boys and girls are far more similar than they are different," says Fine, from the University of Melbourne.

Fine says many pop science presentations claim that neuroscience has shown important differences between boys' and girls' brains, and sometimes suggest the two should be taught differently, and possibly separately.

"These commentators appear to be getting a lot of attention," she says.

Fine says there are three problems with this trend, which can have damaging consequences - not only in classrooms, but at home and work.

First, she says, claims are often made on the basis of isolated brain imaging studies that have not been replicated, and in some cases have found to be wrong.

For example, says Fine, males are often described as having a "spotlight brain" that processes information such as language in one hemisphere, while girls are supposed to have a "floodlight brain", using both sides of the brain.

As part of this idea of a more interconnected female brain, females are supposed to have a larger corpus callosum, the thick band of neurones that connect the two hemispheres.

She says while older smaller studies support these differences, the bulk of more recent data has found otherwise.

"The data overall just don't support these ideas," says Fine.

However, she says, this has not stopped commentators from drawing conclusions based on the earlier studies.

"The supposedly interconnected female brain is claimed to make females better at language, at multitasking and communicating emotion," says Fine.

"While the less interconnected male brain is supposed to leave males lacking in these areas but more focussed and analytic."

Lack of knowledge

Even where findings are more robust, Fine says there are problems in drawing conclusions about their implications because scientific understanding of the brain and how it relates to psychology is still its infancy.

"What the popular writers do is they very confidently draw on gender stereotypes to 'putty-fill' in the enormous gaps in our neuroscientific knowledge," she says.

For example, Fine says, pop science writers argue that aggression in males is explained by controversial findings that the amygdala is larger in males.

But, she says the amygdala is also involved in face recognition, social perception, emotional memory and fear, which tend to be more associated with females.

"We can't simply assume it's an indicator of greater aggression," says Fine.

Fine says everyone is a mix of masculine and feminine qualities and there's no fixed way in which the qualities line up.

"So being good at maths doesn't make it more likely that you'll be more aggressive, for example," she says.

"That's not to say that biological sex doesn't make a difference in terms of the brain, brain development, or brain responsiveness, but it does undermine the idea of the male brain and the female brain."

Behavioural studies

Fine says while brain imaging studies can make exciting news, they overshadow decades of behavioural research that go against the idea that differences matter.

"In the majority of cases, the differences between the sexes are either non-existent or they are so small so as to be of no practical importance in, for example, an educational setting," she says.

"The problem is, when you start talking about girl brains and boy brains, you are actually encouraging educators to do something that all educators understand that they shouldn't do, which is to put people in categories rather than to look at each child as an individual."

Fine says the performance of girls in mathematics is a case that demonstrates the need to look beyond neuroscience to explain what is going on.

"Twenty years ago girls were doing badly at maths, now they're not," she says.

"That must have some kind of correlate in the brain because the brain is the basis of all behaviour. But it's certainly not some enduring quality of the brain."