There are some things in life we understand and accept as true without question: Drink plenty of water. Wash your face before bed. Get at least 8 hours of sleep a night. So when something comes along that challenges one of these life truisms, it kind of blows our mind. (What do you mean, an apple a day won’t keep the doctor away?!)

So where did this 8-hour figure come from, anyway? How did we form these sleeping habits that are, more or less, accepted throughout our society? A study in Current Biology set out to find more. And when you want to study pure, raw human behavior, you go to preindustrial, hunter-gatherer societies, i.e. places like Tanzania, Namibia and Bolivia, where you can find communities that live without electricity and other forms of modern technology.

The goal was to discover if being isolated—both geographically and from pollution and technology—would yield different sleep patterns. Researchers studied 94 members of three societies, representing 1,165 nights of sleep. What they found were more similarities than they expected, with the average sleep duration between 5.7 hours and 7.1 hours—pretty close to our 8 hours. They also found that, like us, the hunter-gatherers didn’t go to sleep just because the sun went down. They did, though, wake up before sunrise.

So, what does it all mean? Many think our sleeping habits are made worse by things like caffeine, pollution and technology. But this study shows that we share similar sleeping patterns with preindustrial societies, free of these distractions. All in all, it sounds like the recommended 8 hours are what your body craves, simply because it’s human nature.

That said, the study doesn’t say anything about taking naps. So if you’ll excuse me, it’s time to curl up for my quick mid-morning snooze.


(Image via Columbia TriStar)