It's a question that has left researchers scratching heads. Why, during this age of extraordinary technological development, did human brains start to dwindle in size? The first writing appeared at roughly the same time. Sprawling civilisations, full of architecture and machinery, soon followed.
'We were expecting something closer to 30,000 years ago.'Īgriculture 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. 'This is much more recent than we anticipated,' says DeSilva. And according to an analysis of cranial fossils, which he and colleagues published last year, the shrinkage started just 3,000 years ago. 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. But since then, human brains have actually shrunk slightly. The people walking around and meeting in the world's earliest cities would have been familiar in many ways to modern urbanites today. Several thousand years ago, humans reached a milestone in their history – the first known complex civilisations began to emerge. Your ancestors had bigger brains than you.
