'Paleo sleep' is not a thing: Hunter-gatherers don't get more sleep than we do

There's a popular notion that our Palaeolithic predecessors — who didn't share our phone-blipping, caffeine-gulping, LCD-saturated lifestyles — enjoyed a longer and more peaceful sleep than we do today. Except they probably didn't, according to a new study.

Researchers from the University of California monitored the sleeping patterns of three ancient groups of hunter-gatherers still living in remote parts of the world and found they don't get more sleep than we do. 

In fact, they only squeezed in around 6.5 hours of Zzzz's a day — below the seven hours averaged by Aussie adults, and less than the Sleep Health Foundation's recommended 7 to 9 hours for adults.

"The short sleep in these populations challenges the belief that sleep has been greatly reduced in the 'modern world,'" said the co-author of the study, Jerome Siegel of the University of California, Los Angeles, in a media release. 

"This has important implications for the idea that we need to take sleeping pills because sleep has been reduced from its 'natural level' by the widespread use of electricity, TV, the internet, and so on."

To test how people slept in before modern times, Siegel and his team looked at three remote pre-industrial societies: the Hadza of Tanzania, the San of Namibia, and the Tsimane of Bolivia.

Researchers recorded the around-the-clock sleeping habits of 94 people over a period of 1165 days.

Although the traditional people in the study were from different parts of the world, they showed striking similarities in their natural sleeping patterns.

"Despite varying genetics, histories, and environments, we find that all three groups show a similar sleep organization, suggesting that they express core human sleep patterns, probably characteristic of pre-modern-era Homo sapiens," Siegel says.

Sleep time among the different groups averaged between 5.7 and 7.1 hours, with between 6.8 and 8.5 hours between the start and end of the sleep period.

Scientists noted that the sleep duration was more affected by temperature than by light, with all hunter-gatherers hitting the hay as the temperature fell and sleeping through the coldest part of the night. They also snoozed more in the winter time, getting in an extra hour a night.

However, Siegel noted that very few of them suffered from chronic insomnia, which could be used to help modern-day sleep disorders.

"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 US population," Siegel says.

While this new insight into our ancestors' sleeping habits does away with the idea of "paleo sleep", there is still evidence that getting away from the trappings of modern life can benefit our slumber. 

One study found that sleeping according to the sun's rising and setting schedule can adjust your circadian rhythms to their natural state, undoing the influence of light bulbs.