Ebook: The Lopsided Ape: Evolution of the Generative Mind

Most people are right-handed, though with a substantial minority of left-handers: this is such a familiar feature of human existence that we rarely think about it at all (especially if we are right-handed), and now that schools no longer try to force left-handers to write with the right hand, the psychological and emotional problems that this once produced have become a distant memory. Michael Corballis, however, thinks about handedness a great deal, and has devoted a large part of his career as a professor of psychology to studying it.

Because we don't think about it much at all, we don't usually notice that bias towards right-handness is a specifically human characteristic. Although animals may prefer to do some actions with one foot rather than the other, they show no consistent bias. To find a comparable case we need to go as far afield as to parrots, which generally prefer to pick up bits of food with their left feet, while standing on their right.

I usually regard discussion left-brain and right-brain specialization as the sort of science that belongs in popular magazines, to be read, perhaps, while waiting for a dental appointment, but otherwise to be treated with the same disdain as signs of the zodiac. Unlike signs of the zodiac, however, lateral specialization of the brain has a perfectly serious aspect, and Corballis makes a strong case that strong handedness in humans is related to an apparently quite different special characteristic of humans, their capacity for language.