Much of what defines us as a species is all in our heads.
First and foremost, we’ve got these big, powerful brains, and small faces tucked underneath a skull that expanded to house our most precious organ.
There’s another trait that researchers once assumed was a Homo sapiens hallmark, based in the brain but most obvious in the upper limbs: Nine out of 10 humans are considered right-handed.
“It doesn’t matter where you find them, humans have that ratio,” says retired University of Kansas anthropologist David Frayer. Across history and geography, our species has shown remarkable consistency. And no other species appeared so strongly biased toward right-handedness.
The trait’s emergence in our species alone, the thinking went, was yet another indication of our superiority, a preference controlled by the brain and directly linked to our capacity for language and tool-making.
Um, no.
As researchers have refined methods and unearthed new ...
