When It Comes To The Brain, Size Doesn’t Matter
Perhaps you’ve heard that we humans are special in the animal world because our brains are so very, very big for our size. Not true, as it turns out. Sure, they’re big compared to a bird brain or a dog brain, but in the primate world our brain size is pretty unremarkable–at least according to this article in New Scientist. What’s probably more important than size is the number of neurons we have packed in there, as well as the number of glia–another kind of brain cell–and the size of certain structures in our brains.
This article debunking the “big is better” brain myth reminded me of a phenomenal book I read when I was an undergraduate, Steven Jay Gould’s The Mismeasure of Man. (I was in college quite a while ago, so it’s not a new book–but it’s still a great one. In 2006 Discover rated it the 17th best science book of all time.)
I can’t recommend it enough. It’s a book that sets out to prove the falsity of biological determinism–the belief designed to excuse social inequality by arguing that biology makes certain races, ethnicities, and genders smarter than others. One of the things Gould does is repeat 19th century experiments of craniometry–measuring skulls to determine brain size. The original experiments found that white men (and somewhat unexpectedly, Iroquois men) had the biggest brains, a fact which supposedly explained their superior intellect. Other races and all women had significantly smaller brains, which was used as evidence of lesser intelligence.
When Gould reconstructed the experiments, he demonstrated that the original findings were totally inaccurate. The race and gender prejudices that the original scientists held changed how they performed the experiments, whether those scientists were aware of it or not. Ultimately, Gould proves a couple of things through his reconstruction: 1) that scientists, like everyone else, can bring preconceived notions to the table that influence their experimental outcomes, and 2) that brain size has a lot to do with body size and not a lot to do with intelligence.
In a later edition of the book, Gould also takes on IQ tests and the theories offered in The Bell Curve. Writing this post has made me want to reread it. I hope it’s as good as I remember!