Of bairns and brains

HUMAN intelligence is a biological mystery. Evolution is usually a stingy process, giving animals just what they need to thrive in their niche and no more. But humans stand out. Not only are they much cleverer than their closest living relatives, the chimpanzees, they are also much cleverer than seems strictly necessary. The ability to do geometry, or to prove Pythagoras’s theorem, has turned out to be rather handy over the past few thousand years. But it is hard to imagine that a brain capable of such feats was required to survive on the prehistoric plains of east Africa, especially given the steep price at which it was bought. Humans’ outsized, power-hungry brains suck up around a quarter of their body’s oxygen supplies.

Sexy brains

There are many theories to explain this mystery. Perhaps intelligence is a result of sexual selection. Like a peacock’s tail, in other words, it is an ornament that, by virtue of being expensive to own, proves its bearers’ fitness. It was simply humanity’s good fortune that those big sexy brains turned out to be useful for lots of other things, from thinking up agriculture to building…Continue reading
Source: Economist