An old theory about autism and the brain is getting a fresh look from autism experts in the U.K.

The theory of the “extreme male brain” was first mentioned more than 60 years ago, writes Simon Baron-Cohen, PhD, and colleagues in Science.

Now, they’re exploring that theory in light of brain anatomy. Still, no one knows exactly what causes autism and related brain disorders.

Baron-Cohen is a professor of developmental psychopathology at the University of Cambridge. He also directs the university’s Autism Research Centre.

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Extreme Male Brain

The “extreme male brain” is an exaggeration of the typical male brain, which is stronger at analyzing systems than showing empathy, or so the theory goes.

The researchers write that “leaving political correctness aside, there is compelling evidence” of differences in the brains, mental function, and behavior of men and women.

They cite psychological studies -- some of which were done decades ago -- that girls tend to play with dolls, boys favor mechanical toys, girls score better on tests of social sensitivity and verbal fluency, and boys score better on engineering and physics problems and spatial navigation.

Those theories are based on large groups of people, not individuals, and shouldn’t be used to make assumptions about men or women, the researchers warn.

Other experts dispute many gender differences.

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Autism and the Brain

People with autism often have “empathy deficits” and some are very skilled at systematizing, the researchers note.

They cite studies showing that the autistic brain seems to follow the development of the male brain, but to a stronger degree.

Scientists should map the autistic brain, looking for what areas are (and aren’t) “hypermasculinized,” write Baron-Cohen and colleagues.

Autism is more common among males. But it’s important to study the female autistic brain, too, the researchers write.

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By Miranda Hitti, reviewed by Louise Chang, MD

SOURCES: Baron-Cohen, S. Science, Nov. 4, 2005; vol 310: pp 819-822. News release, Science.