Why Are Women's Brains Smaller? Maybe Because Men "Domesticated" Them, The Same As Farm Animals

Well! It seems Ron Burgundy was right:

Your brains are one third the size of ours. It's science.

It's a thesis that manages to insult men by calling them cruel slavemasters who treat women like chickens, and also manages to insult women by calling them, brain-wise, chickens.

WHY DO WOMEN have smaller brains than men? Male brains weigh around 1.25kg; female brains weigh on average 100g less. One possible answer comes from an unexpected study of foxes. In 1959 Dmitri Belyaev, a Russian geneticist, launched a long-term experiment to tame foxes. Starting with a population of caged wild animals, he selected from each generation the puppies who were friendliest (or, initially, least hostile) to humans, breeding only from them. After 35 generations he produced animals that had been transformed from the usual snarling fearfulness of wild foxes into animals that were similar to domestic dogs. The tamed foxes wagged their tails, whined for affection, were submissive, barked like dogs and their ears flopped. As Darwin said: “Not a single domestic animal can be named which has not in some country drooping ears.� Belyaev seems to have concertinaed all this into 50 years when it took 10,000 years to domesticate wolves as dogs.

And the tame foxes’ brains were smaller. Domestic animals generally do have small brains. On average, domestic dog, cat, sheep and pig brains weigh 25 per cent less than those of wild animals. The mechanism remains a mystery. A recent study by Elena Jazin and her colleagues from Uppsala University in Sweden, published in Current Biology, reported that of 30,000 brain genes about 40 showed differences between tame and wild foxes. All we do know is that blood levels of stress hormones are lower in tame than wild animals and that brain levels of anti-stress hormones are higher.

But would it be dangerous to suppose that women’s brains are smaller than men’s because, over the millennia, we men have been selecting friendly women with whom to breed? And that therefore we have domesticated them? And that they, in turn, have selected assertive men?

It would be a dangerous to suppose that within earshot of most of the women I know, yes.

It's not all a downer, though, ladies:

In any event, small brain size seems to optimise emotional intelligence.

As nasty a supposition as this is, for both sexes, there may be something to it. And awful lot of the brain is taken up with hand-eye coordination and spatial relationship estimations -- stuff that men would be expected to use more of, being the hunters, and so maybe the difference in sex roles bred men with bigger areas of the brain dedicated to these sorts of tasks than women have.

But that could just mean the bulk of the difference in brain size occupied by baseball-throwing-and-catching sort of tasks.

Meanwhile, the shoe-selection-and-appreciation part of women's brains (the "footwear cortex") is said to be friggin' enormous.

Thanks to Piglito.

posted by Ace at 12:15 PM

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