‘Paleo’ sleep? Hunter-gatherers don’t get more sleep than we do

Technology has been blamed for causing many of us to get a bad nights sleep.

Sleep researcher Christoph Nissen of the University of Freiburg says that though he’s surprised that the three groups sleep as little as they do, the new study represents a few of the first solid information on how Stone Age people might have slept.

The new study, published in the Cell Press journal Current Biology, shows that three ancient groups of hunter-gatherers living in different parts of the world without any of those trappings of modern life don’t get any more sleep than we do.

“Mimicking aspects of the natural environment experienced by these groups might be effective in treating certain modern sleep disorders, particularly insomnia, a disorder affecting more than 20 percent of the USA population”, Siegel says.

On average, the hunter gatherers stayed up a little over three hours after the sun set and woke before sunrise. Far from exceeding those of a modern city-dweller, these values are near the low end of the range found in industrial societies.

All of the researchers agree that hypnotic sleeping pills like Ambien and Lunesta should be taken only as a last resort, and that sleeping pills have been tied to a shorter life span. Kripke suggests that the “myth” of the eight-hour sleep cycle has been used by sleeping pill companies to help sell their products. That’s less than is recommended for our health, yet the groups seemed very healthy indeed.

The research proved hard at times, Siegel said. “The two groups we quizzed on this don’t have a word for insomnia”.

“We can say absolutely that less than six hours of sleep is problematic in industrial societies”, Dinges says. “This paper questions, is that data flawed? Or it could be that the sleep we’re getting is lower quality, and we need more of it to feel restored?”

The study doesn’t necessarily mean that you need less sleep, though, Siegel says.

The scientists found that the amount of sleep these hunter-gatherers got had less to do with the length of daylight hours than with temperature. They wake up when the day begins warming from the sunrise. However, a recent study suggests eight hours of sleep may not be as integral to our health as we have been led to believe. Typically, people fell asleep several hours after sunset, and rose an hour before dawn.

Whether those who hunt and gather have anything to teach the modern world, then, is moot.

Most of the people studied by Siegel’s team slept less than seven hours each night, clocking an average of six hours and 25 minutes. “I think the beauty of this current study is that maybe we shouldn’t be ramming this requirement down [every person’s] throat so to speak”, she says.

“They are sleeping through the coldest period of the night”, he says. They did, however, sleep one more hour per night in winter, Siegel says. So were stress levels – which is linked to insomnia – taken into consideration? “The evidence is that people differ in sleep as they do in height and eye color and there isn’t a magic number”. Those people need more sleep. Their lifestyles are seen as analogous to ancient human societies.

For instance, temperature is a variable often underrepresented in sleep research. In comparison, 10 to 30 percent of people in industrial societies report chronic insomnia, the scientists noted. All live largely by hunting and gathering.

This suggests that, contrary to what a few might assume, perhaps the human body doesn’t really need 8 hours of sleep each day after all and can easily do with just under 7. But he’s excited about other possibilities. These groups live like hunter and gatherers and rarely interact with modern amenities, including electric light, which is considered to be one of the major modern disruptors of sleep. He has a dry wit and no hobbies.