Is sleeping like our ancestors better or worse?

We tend to idealise the past. We believe that life was somehow simpler when all you had to think about was avoiding being eaten by the carnivore-du-jour. We regard modernity with mistrust and suspect that at some point technology will usurp us as the ambient life-form. We think that phones and social media have degraded our social interactions. Yet, was the past really so much better? Now a new a study has shown that as far as sleep is concerned the past may not have been so wonderful after all.

It is difficult to project accurately onto life in the past without making assumptions so to get an idea of what life may have been like for our Paleolithic ancestors these researchers examined three traditional hunter-gatherer societies still in existence. Those societies were the Hadza of Tanzania, the San of Namibia, and the Tsimane of Bolivia. The researchers collected around the clock sleeping data for members of these societies so that they had 1,165 days worth of data in all.

All the evidence suggests that sleep is absolutely crucial to mental and physical wellbeing but perhaps the 7-8 hours common in modern industrial societies isn't so bad after all.

The findings regarding sleep were remarkably similar across the three groups. Sleep time averaged between 5.7 and 7.1 hours with between 6.9 and 8.5 hours between the beginning and end of sleep period. We know that hunter-gatherers sleep an average hour more in winter than summer but these results showed that none of them went to sleep when the sun went down. In fact they stayed up on average three hours after sundown and awoke before the sun rise. It seems that sleep time had more to do with temperature rather than light as they went to sleep when the temperature began to drop and then slept through the coolest time of the night.

These figures put them at the low end of sleep duration in industrial societies. It looks as though the fear that we might be lacking sleep due to all our devices might be a little overblown. Perhaps it was sparked by comparisons to those Victorian era diaries that suggest a sleep duration of ten hours a night. Maybe those Victorians just wanted to sleep longer so they didn’t have to wear those clothes? All the evidence suggests that sleep is absolutely crucial to mental and physical wellbeing but perhaps the 7-8 hours common in modern industrial societies isn’t so bad after all.

What the researchers do note, is that there is no insomnia in hunter-gatherer societies. We could speculate wildly as to why that might be so (and it is so tempting to do so) but the researchers suggest that aspects of the hunter-gatherer lifestyle might just help our modern insomniacs.