Why human brains were bigger 3,000 years agoBy Chris Baraniuk
8th May 2022
Our modern civilisation may be the most advanced to ever exist on Earth, but around 100 generations ago, our ancestors had brains that were larger than our own.
Your ancestors had bigger brains than you. Several thousand years ago, humans reached a milestone in their history – the first known complex civilisations 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. And according to an analysis of cranial fossils, which he and colleagues published last year, the shrinkage started just 3,000 years ago.
"This is much more recent than we anticipated," says DeSilva. "We were expecting something closer to 30,000 years ago."
Agriculture emerged between 10,000 and 5,000 years ago, although there is some evidence that plant cultivation may have started as early as 23,000 years ago. Sprawling civilisations, full of architecture and machinery, soon followed. The first writing appeared at roughly the same time. Why, during this age of extraordinary technological development, did human brains start to dwindle in size?
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Source:
https://www.bbc.com/future/article/20220503-why-human-brains-were-bigger-3000-years-ago
