We have all kinds of comforts in the modern era, but a good night’s sleep isn’t one of them for many people. Despite not having the conveniences of an industrialized society, our ancestors didn’t have it much better in terms of hours spent in the sack.
Prehistoric humans didn’t get any more sleep than their modern descendants, found a study published today in the journal Current Biology. Scientists didn’t find this out by digging up some kind of paleolithic alarm clock, of course. Rather, a team led by University of California, Los Angeles, researchers examined the sleep habits of three hunter-gatherer tribes whose behaviors mimic those of pre-modern humans.
On average, people in traditional societies slumber an average of 6.5 hours per night. That’s in line with the amount of sleep the typical American gets, around 6.8 hours per night, according to a Gallup poll released in 2013. The hunter-gatherers also don’t nap regularly, so they’re certainly not catching up on hours lost overnight.
Although the hours clocked more or less mimic those of humans in the industrialized world, there are some notable differences. For starters, the hunter-gatherers tended to wake up before dawn. They didn’t sleep right after the sun went down, but usually a few hours afterward, during the coldest parts of the night.
Similar sleep patterns have been identified in other communities living according to pre-industrial customs. The town of Baependi, a small rural community in southeastern Brazil, for example, sticks to more of a solar rhythm in their sleep patterns, found a team of researchers from the University of Surrey and the University of Sao Paolo.
Perhaps the most enviable quality of slumberers in traditional societies, the UCLA researchers discovered, is that chronic insomnia, a condition that affects an estimated 20 percent of Americans, is rare among hunter-gatherers.
That fact might be eye-opening to the millions of Americans who spend more than $32 billion annually on everything from “pills, products and medical devices to “sleep consultants” who farm themselves out to hospitals, labs, and sleep centers, to luxe mattresses made with tension-relieving foams,” according to a 2012 report by The Fiscal Times. Tribesmen with no access to expensive bedding let alone sleep aids typically had no problem getting a good night’s rest.
Part of the reason for hunter-gatherers being sound sleepers might be due to lifestyle factors. After all, they tend to be active by necessity, given the lack of comforts like grocery stores or chairs. Another contributing factor is that hunter-gatherers follow more natural sleep rhythms, unlike most people in industrialized society who use artificial light to extend their productive hours.
In fact, a separate study published in the Journal of Biological Rhythms in June found that electrification and artificial light in modern societies disrupts sleep cycles and can lead to sleep deprivation. For the study, two different hunter-gatherer societies with similar ethnic and sociological backgrounds were identified in northeastern Argetina.
The only significant manner in which the two tribes differed was that one had access to electricity, and the other group didn’t. The researchers found that the community with access to artificial light tended to sleep one hour less than the one that didn’t.
People in preindustrial societies not only followed more natural rhythms in terms of the timing of their sleep; they also slept in segments rather than resting a continuous seven or eight hours, reports the BBC World Service. Instead, in traditional societies, people often slept in two, three- to four-hour periods broken up by one to two hours of wakefulness. That hours or two of consciousness wasn’t just spent tossing and turning of course, but used productively, spent conversing or being intimate with bedmates.
So our ancestors likely didn’t sleep any more than we do today, but the quality of their sleep may have been better than what their tech-savvy descendants experience on a nightly basis.