Relax! No day nap or eight-hour sleep for our ancestors either

Deep sleep is much better in offering the needed rest compared to longer sleep duration with disturbed sleep.

“The researchers haven’t shown anywhere [in the paper] that they [the traditional hunter-gatherer people] are performing well so we don’t know if the sleep [they are having] is sufficient for them to be performing optimally”, he said.

To learn more about their sleep patterns, the researchers outfitted volunteers with small activity monitors that are worn on the wrist like a watch. The people studied consistently slept during the nightly period of declining ambient temperature, Siegel found. Invariably, they woke up when temperatures, having fallen all night, hit the lowest point in the 24-hour period.

In fact, according to the authors of the study, the common complaint that the “modern world” reduces our ability to sleep has been recorded as far back as the 1880s.

People complain that modern life allows us less sleep than is natural, and earlier studies done on animals in captivity gave the researchers an idea for studying sleep in people, Siegel said.

Scientists studied the sleep of three current preindustrial societies – the San tribe from Namibia, the Hadza of Tanzania and the Tsimane tribe from Bolivia. In total 94 people in total were tracked for six to 28 days each throughout the seasons, creating sleep data for 1,165 separate days.

Gandhi Yetish, who led the researchers from the University of California, said: “There’s this expectation that we should all be sleeping for eight or nine hours a night, and if you took away modern technology, people would be sleeping more”.

The researchers found actual sleep time averaged between 5.7 and 7.1 hours, and despite a lack of electricity and lights, the people stayed awake for about three hours after dark and tended to wake before sunrise. But they appear to spend a similar amount of time sleeping as do people in hunter-gatherer communities in Africa and South America, a new study finds.

With this in mind, they sought to establish what “natural” sleep patterns might be without the distractions of modern lighting, heating and electronic gadgetry.

Most people fell asleep on average 3.3 hours after sunset.

But the president of the AASM told the New York Times that most studies on the topic rely on self-reported sleep data and it’s very possible that people overestimate the amount of ZZZs they’re getting by saying how long they’re in bed, which is different from how long they’re actually conked out. The groups recommended that people who are concerned they are not getting the right amount of sleep consult a health-care professional.

The Hadza and San are “hunter-gatherers” and the Tsimane are considered “hunter-horticulturalists”, growing a few of their food.

Do teenagers need more sleep than adults?

Previous research has linked lack of sleep to ills ranging from poor judgment to obesity to heart disease.

The study findings challenge the assumption that the particular pressures and stresses of the modern world have greatly reduced sleep, says Siegel, who heads UCLA’s Center for Sleep Research. “The sleep in these traditional human groups is more similar to sleep in industrial societies than has been assumed”, the authors write.