Jump to Main ContentJump to Primary Navigation

Evolution, not your smartphone, might be to blame for your bad night's sleep


It really feels like we as a society are getting much worse at sleep. All we want to do when we hit the pillow is drift off to a pleasant land of dreams, where fluffy dogs can talk and everyone gives you free brownies. But the older you get, the trickier that becomes.

Generally, the blame is apportioned to flickering smartphone screens suppressing our natural melatonin. Late-night Twitter scrolls and Reddit rabbit holes are bad, say the experts. 

But what if restless sleep is an evolutionary tool that once upon a time protected us from nocturnal predators and enemy ambushes? That’s the suggestion from scientists at the Duke University in North Carolina, who for three weeks closely observed the sleeping patterns of modern-day hunter-gatherers in northern Tanzania. 

33 members of the Hazda tribe, aged between 20-60 and in good health, were asked to wear motion sensors for the duration of the study. They found that over the course of 220 hours, everyone slept at the same time for only 18 minutes. The younger people tended to go to bed later, while the elderly tribe members were more likely to rise early. But the important thing was that, due to the wide range of age groups, there was nearly always at least one person awake at any given time. 

Sleep man

You, being rubbish at sleeping

During the day, the men and women would go off to forage for tubers, berries, honey and meat, before reuniting with the rest of the tribe in the evening. Typically, they’d all sleep together either outside or in huts made of branches and grass. Nobody had their natural sleep cycle interrupted by Rocket League or glowing Facebook statuses, yet the researchers still observed inconsistent sleep. In fact, we in the west are probably getting more kip, despite being permanently attached to gadgets.

“They tell an important part of the human evolutionary story because they live a lifestyle that is the most similar to our hunting and gathering past,” said co-author Alyssa Crittenden, an associate professor of anthropology at the University of Nevada.

“They sleep on the ground, and have no synthetic lighting or controlled climate traits that characterised the ancestral sleeping environment for early humans.”

The researchers said that that differing sleep schedules, rather than insomnia or technology overkill, could be down to vigilance. If you’re in a lighter sleep you’re better equipped to respond to any sudden threats, which would have been necessary thousands of years ago. Perhaps this is something all human beings have inherited, and they believe it could help explain why people tend to have more sleep-related problems as they get older. 

“A lot of older people go to doctors complaining that they wake up early and can’t get back to sleep,” said Charlie Nunn, also a co-author of the study. “But maybe there’s nothing wrong with them.”

“Maybe some of the medical issues we have today could be explained not as disorders, but as a relic of an evolutionary past in which they were beneficial.”

So there you have it. Don’t blame Instagram and Simpsons memes for your lack of shut-eye, but your ancestors.

(Images: iStock)



Here are all the things summer has ruined because it's too damn hot


These two facts will make you want to change your sheets immediately


This 12-year-old CEO is here to show you how little you've achieved


Sir Bruce Forsyth has died aged 89

The legendary presenter has died aged 89

by Gary Ogden
18 Aug 2017

The biggest stereotype about men and sex is actually a load of rubbish

We've been wrong this whole time

by Gary Ogden
18 Aug 2017

Discover the words that became cool in the year you were born

Were you born in the year of booty calls or cybersex?

by Emily Reynolds
18 Aug 2017

This German town came up with a genius way of humiliating neo-Nazis

Is this the best possible way to deal with them?

by Alex Finnis
18 Aug 2017

Donald Trump’s lawyer: possibly not racist, definitely not intelligent

Oldest trick in the book

by Tom Victor
17 Aug 2017

The 10 worst cities in the world to live in 2017

To put your first-world problems into perspective

17 Aug 2017

We have some very, very good news about cheese

Cheese lovers, it's our time to shine

by Emily Reynolds
17 Aug 2017

Jurors refuse to work on Martin Shkreli's trial for the best reasons

He is *not* a popular man

by Emily Reynolds
17 Aug 2017

Apparently millennials hate boobs now - but what do we like instead?

These god damn millennials, eh

by Gary Ogden
17 Aug 2017

All the times Donald Trump has failed to condemn far-right extremists

This has gone on for some time

by Tom Victor
16 Aug 2017