Research reveals ancestors likely slept less, not more

A study from the UCLA Center for Sleep Research debunks the myth that modern humans get less sleep than our ancestors and are thus less healthy.

By studying hunter-gatherer peoples in regions of Sub-Saharan Africa and South America that still live how humans did thousands of years ago, researchers determined that sleep cycles averaged between five and seven hours a night.

“It’s absolutely incorrect to think that the more you sleep, the healthier you’re going to be,” said director of the study Jerry Siegel.

Common thought has long assumed humans went to sleep when the sun went down and woke with the dawn, but the research team found that hunter-gatherers do not go directly to bed after dark.

They also discovered that each group, regardless of where they were, consistently woke up when temperatures reached the lowest point during the night. For most of us today, temperatures where we sleep are controlled with heat and air conditioning.

“There’s no question that light affects sleep,” he said. “But light may have been connected to sleep largely because of its connection to temperature.”

The adults in the groups studied showed good health and low levels of fatigue during the day. They also have significantly fewer cases of insomnia than reported by people living in the industrialized world.

Studies show that sleep-deprived individuals have higher rates of health problems like obesity, heart disease and difficulty concentrating during the day.

More research will continue to be done into why hunter-gatherers seem to sleep much better.

Vocab

• hunter-gatherer – a member of a nomadic culture in which people hunt, fish, or forage in the wild
• sleep deprivation – the state of not having something people need, in this case, sleep
• REM – “rapid eye movement,” the period of the sleep cycle when continuous movement of the eyes signals that dreaming is taking place
• insomnia – inability or difficulty falling or staying asleep, especially over a long period of time