Thursday, 6 March 2008

Neural Dimorphism and Discrimination

Or in other words, Boys and Girls aren't just different between their legs, they differ between their ears too.

From Science Daily :
What was once speculation is now being confirmed by scientists: the brains of women and men are different in more ways than one.

Discoveries by scientists over the past 10 years have elucidated biological sex differences in brain structure, chemistry and function. “These variations occur throughout the brain, in regions involved in language, memory, emotion, vision, hearing and navigation,” explains Larry Cahill, Ph.D., an associate professor in the Department of Neurobiology and Behavior at the University of California, Irvine.

While women and men struggle to communicate with each other and ponder why they don’t think and react to things in similar ways, science is proving that the differences in our brains may have more serious implications beyond our everyday social interactions.
That's a "Pop sci" view. The more abstruse articles sound something like this:
Sex differences in neural processing of language among children. Douglas D. Burmana, Tali Bitanc and James R. Bootha. Neuropsychologia. doi: 10.1016 / j.neuropsychologia.2007.12.021.

Abstract. Why females generally perform better on language tasks than males is unknown. Sex differences were here identified in children (ages 9–15) across two linguistic tasks for words presented in two modalities. Bilateral activation in the inferior frontal and superior temporal gyri and activation in the left fusiform gyrus of girls was greater than in boys. Activation in the left inferior frontal and fusiform regions of girls was also correlated with linguistic accuracy irregardless of stimulus modality, whereas correlation with performance accuracy in boys depended on the modality of word presentation (either in visual or auditory association cortex). This pattern suggests that girls rely on a supramodal language network, whereas boys process visual and auditory words differently. Activation in the left fusiform region was additionally correlated with performance on standardized language tests in which girls performed better, additional evidence of its role in early sex differences for language.
I try on my blog to give a view somewhere between the almost content-free but easily read PopSci, and the fact-filled but intellectually indigestible academic paper. (And parenthetically, note the young ages of the experimental subjects - this stuff happens before the gross changes to neuro-anatomy that occur with puberty. The functional difference is apparent before changes detectable at autopsy happen.)

One can take this dimorphism too far though.

It's undisputed that Swedes are taller, in the main, than Japanese. Yet no-one would exclude a 6ft 4" Japanese from a Basketball team because they were "too short", yet include a 5' Swede because "Swedes are tall". But we are constantly confronted with women being excluded from professions which are traditionally male, and the reverse. People differ, and just because most men have certain capabilities dictated by sex-specific neurology that most women lack, and the reverse, that doesn't mean we shouldn't treat everyone as individuals on their merits.

I've been accused of being an "essentialist" on several feminist blogs, simply because I've pointed out the scientific evidence of sexual dimorphism in the brain. I'm interested in the subject only partially because of my own unusual medical history, as a computer scientist of course I'm interested in the way we think, why and how. I'm also active in several groups, encouraging young women to become engineers and computer scientists, traditional male occupations. This is because neurology might explain why about 30% of engineers should be female, but can't explain why only 8-12% are in actuality. No, the fact that there isn't a 50/50 mix is not purely because of Male Patriarchal Privilege. But no, the fact that many young women are discouraged and dissuaded from taking up careers they are both interested in, and have talent for, is not because "men are better at it than women are". Having been on both sides of the fence (as it were), I'm acutely aware of the social sanctions that many women face in professional life. I'm the classic experiment, "take one person, and if they were perceived as male, see how they were treated, then with exactly the same qualifications and professional record, see how they were treated if they were female". I was an intellectual feminist before, though I had doubts as to the extent of the problem. Now, having experienced the difficulties myself, I realise that if anything, the problems were understated - though perhaps not as understated as the difficulties men face in some areas, difficulties that even they don't see they suffer from. They're lesser, but they exist. As regards my Feminism now, this time it's personal, and I have the facts behind me.

Gender is not purely a social construct, though much of the behaviour patterns we associate with gender specificity are. Both social construction and biological differentiation play roles. Too often we have two sides, one claiming that gender doesn't exist as an objective phenomenon outside social science (and by corollary, transsexual people don't actually exist except by social fiat, or as dupes or agents of the Patriarchy), while the other claims that men are men, women are women, and transsexual people don't exist, only the insane, the deluded, or those making a perverse political statement. Caught in the crossfire are those who see the gender binary as something quite real, but only as a really good approximation, not an Absolute and Universal Truth . People who are searching for facts, regardless of political or even theological consequences. And in a few cases, people whose narratives and accounts of their existence are denied by both sides simply because they are not in accordance with either view in its entirety. People whose very existence others find... inconvenient. If we're lucky, they ignore us. If not, they erase us.

And all this just from a minor glitch in neuro-anatomy, probably just a hormonal imbalance during the first trimester of gestation, and certainly something that happens to a proportion of the population quite naturally. Jeez, what a mess.

1 comment:

Stellewriter said...

There are a multitude of endocrine blockers these days to alter the very early gestation and development of a fetus. What is done in those early days can affect a life time. And how the social context is applied can color that growth as well. The 2006 estimates in medical research indicate that 1/2500 are born ambiguous with indeterminate gender of sexual identity. How many more of us are so born to a lesser degree of anomaly, and where is the dividing line?