Before the widespread use of modern electric lighting, humans did not sleep in one continuous eight-hour block. Instead, ...

Add Yahoo as a preferred source to see more of our stories on Google. A painting of a woman waking up. The wild thing about Ekirch's study was that the evidence of biphasic sleep was staring us in the ...

A number that sounds like plenty for humans turns out to be the smallest ration of sleep in the entire primate order. Biologists are still working out why. Seven hours sounds like a reasonable, even ...

Sleep is often treated as a casualty of modern life. Artificial lighting, shift work, endless notifications and late-night entertainment are usually blamed for cutting into the hours people spend ...

On dry nights, the San hunter-gatherers of Namibia often sleep under the stars. They have no electric lights or new Netflix releases keeping them awake. Yet when they rise in the morning, they haven’t ...

Add Yahoo as a preferred source to see more of our stories on Google. Author David Samson has climbed trees to study chimpanzee nests in his quest to understand how human sleep evolved. - Bill McGrew ...