It’s tempting to believe that people these days aren’t getting enough sleep, living as we do in our well-lit houses with TVs blaring, cell phones buzzing, and a well-used coffee maker in every kitchen. These people were members of the Hadza (northern Tanzania), San (Namibia), and Tsimane (Bolivia) tribes. Instead of going to sleep right at dusk, the hunter-gatherers were sleeping an average of 2.5 and 4.4 hours after sunset – well after darkness had fallen.
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“Darkness alone doesn’t force sleep and probably never has in humans”, Siegel said. In contrast, sleep typically continues well after sunrise in industrial populations. And while there’s no time machine to determine how those who came before us got more sleep, this could be a good indicator of the past. Two of the cultures don’t even have a word for insomnia.
“They do not sleep more than most individuals in industrial societies”, the study authors wrote Thursday in the journal Current Biology.
We blame technology and the pace of modern life for our inability to sleep, but new research suggests our sleep patterns have not strayed far from our paleo roots.
Another fascinating finding from the study had to do with the circadian rhythms related to sunlight.
And they even claim it is a myth that modern living is robbing us of precious time in bed.
What kind of research was this?
The authors state this may have health implications. Such alleged sleep deprivation is sometimes held responsible for a rise of obesity, mood disorders and other modern ailments.
With this in mind, they sought to establish what “natural” sleep patterns might be without the distractions of modern lighting, heating and electronic gadgetry.
What did the research involve? They were also fitter.
This characteristic could have evolved to save energy by reducing the temperature difference between the body and environment and consequent heat loss.
Surprisingly, natural light did not have as big an influence as was thought. Sleep onset is the length of time it takes to go from being fully awake to sleep – the “getting to sleep” phase.
Despite not having electricity, the peoples studied did not turn in at dusk.
The data indicated that all three groups slept slightly less than 6.5 hours a night. On average, they stayed up a little over three hours after the sun went down and woke up before sunrise. Once asleep, they racked up about six and a half hours of rest – which researchers said is on the low end of adult averages in industrialized societies.
Other recent studies also show that the 8-hours-of-sleep rule may be outdated, but for a different reason.
How did the researchers interpret the results? He was studying the sleep of wild lions when he got the inspiration to monitor the sleep of pre-industrial people, whose habits might provide insight into the slumber of early humans.
Do teenagers need more sleep than adults? “I don’t think we could just fling someone back into an equatorial lifestyle, and that’ll be entirely beneficial”, he says.
Nevertheless, Dr. Siegel added that not the net duration is what really makes us feel fresh in the morning, but the quality of our sleep.
“Sleep occurs nearly entirely during the dark period in these traditional societies”.
Obviously, what with our ancestors being long gone, the researchers couldn’t simply go around stalking a few to learn about their sleeping habits. So were stress levels – which is linked to insomnia – taken into consideration?
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“In all three groups they are sleeping during this period of falling temperature and in our homes we sleep in a fixed temperature”, Dr Siegel observed.
