The human sleep gap isn’t merely the result of round-the-clock access to artificial light from streetlamps and computer screens, the researchers say. A separate study of the sleep habits of people living in three hunter-gatherer societies without electricity in Tanzania, Namibia, and Bolivia found they get slightly less shut-eye than those of us with electronic gadgets.
If artificial light and other aspects of modern life were solely responsible for shortening our sleep, we’d expect hunter-gatherer societies without access to electricity to sleep more, Samson says. Rather, the study by Samson and Duke anthropologist Charlie Nunn suggests that humans replaced sleep quantity with sleep quality long before the glare of smartphones came to be.
The researchers attribute the shift towards shorter, more efficient sleep in part to the transition from sleeping in “beds” in the trees, as our early human ancestors probably did, to sleeping on the ground as we do today. Once on the ground, Samson says, early humans likely started sleeping near fire and in larger groups in order to keep warm and ward off predators such as leopards and hyenas—habits which could have enabled our ancestors to get the most out of their sleep in the shortest time possible.
http://www.futurity.org/sleep-time-human-animals-1070602-2/
No comments:
Post a Comment
Due to a small but consistent influx of spam, comments will now be checked before publishing. Only egregious spam/illegal/racist crap will be disapproved, everything else will be published.