August 8, 2005

"Innate" Gender Differences and ... Autism?

Today's New York Times features an Op-Ed by Professor Simon Baron-Cohen of Cambridge University arguing that, when viewed on the level of broad statistical tendencies across the whole of the human race, males and females exhibit marked neuro-psychological differences, in some ways similar to those suggested by Harvard president Lawrence Summers (you all remember the uproar that ensued). Eager to avoid the mistake made by Dr. Summers, Professor Baron-Cohen is very careful to emphasize the "on the level of broad statistical tendencies" part, and for this I applaud him. As he says in the article, "the differences that show up in brain research reflect averages, meaning that they emerge only when you study groups ... The evidence to date tells us nothing about individuals."

Professor Baron-Cohen's study divides people into Type E, Type S, and Type B brains based on answers to survey questions (neuro-physiology was also studied, but we're getting to that part). Type E brains are those who have a predisposition for emotional empathy over systematic thought, Type S brains are more disposed to systematize the world than to empathize with the emotions of others, and Type E brains perform each function approximately equally. According to the study, 44% of women are Type E, and 17% are Type S. The numbers are almost exactly reversed for men, with 54% Type S and 17% Type E.

Interpreted as purely statistical data, rather than as "law" regarding the innate aptitudes of persons of different gender, these statistics are more or less common knowledge; they line up with experience. But what is the cause of this difference? Professor Baron-Cohen's group argues that at least some of this has to do with biology rather than environment, noting, for instance, that "on average, at 24 hours old, more male infants will look at a mechanical mobile suspended above them, whereas more female infants will look at a human face." No statistics are provided on this, but it sounds pretty convincing to me, and it doesn't particularly surprise me. The explanation provided by the study is that an individuals "brain type" in the classification system is determined by pre-natal testosterone levels. These findings also correlate to statistics about the size of various portions of the brain, etc., which again suggest heredity rather than environment.

The real clencher is that the article goes on to argue that autism is caused by excessive pre-natal testosterone levels, so that, in essence, autistics are "extermely male" in brain-function. He supports this by the two observations that (a) it is very common for autistic children to have parents who are both extreme Type S brains, and (b) autistics generally have an extremely pronounced disposition to systematize the world around them. Most interesting...

Posted by Kenny at August 8, 2005 9:16 PM
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