Your ancestors had bigger brains than you. Several thousand years ago, humans reached a milestone in their history – the first known complex civilizations began to emerge. The people walking around and meeting in the world’s earliest cities would have been familiar in many ways to modern urbanites today. But since then, human brains have actually shrunk slightly.
The lost volume, on average, would be roughly equivalent to that of four ping pong balls, says Jeremy DeSilva, an anthropologist at Dartmouth College in the US.
At first glance, or should I say squint, ant brains might seem hopelessly different to ours…. But some ant societies share striking similarities with our own. Amazingly, there even are ant species that practice a form of agriculture in which they grow huge swathes of fungus inside their nests.
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When DeSilva’s team compared the brain sizes of various ant species, they found that sometimes those with large societies had evolved bigger brains – except when they had also evolved this penchant for fungus-farming.
It suggests that, for an ant at least, having a bigger brain is important for doing well in a large society – but that more complex social systems with greater division of labor might, in contrast, prompt their brains to shrink.