What Hunter-Gatherers Can Teach Us About Better Sleep
How did humans sleep before electricity, cell phones, and modern life took over?
You might be surprised — we didn’t sleep more. But we did sleep differently.
A groundbreaking study by sleep researchers examined three traditional hunter-gatherer groups — the Hadza of Tanzania, the San of Namibia, and the Tsimané of Bolivia — to uncover what “natural” human sleep really looks like.
Their findings challenge a lot of what we assume about how much sleep we need and how we should time our sleep.
How Much Did They Sleep?
The average total sleep time was 5.7 to 7.1 hours per night — that’s about the same (or even less) than many people in modern society.
But here’s what’s different:
They didn’t nap often — less than 7% of days in winter, 22% in summer
They rarely woke up in the middle of the night
Sleep onset was delayed — they didn’t go to bed right at sunset, but instead fell asleep 3.3 hours after
They woke up just before sunrise, often with the lowest ambient temperature
This means they weren’t strictly following the sun — temperature, not just light, seemed to regulate their sleep.
Why Temperature Matters for Sleep
All three groups consistently:
Fell asleep during the period of falling nighttime temperatures
Woke up at the coldest point of the night (the temperature nadir)
Had a body temperature change (vasoconstriction) to help wake up
This suggests that our bodies may be wired to fall asleep as the environment cools — and that we naturally wake up when it’s coldest.
Tip: Lower your thermostat or take a warm bath an hour before bed to encourage this natural cool-down.
Light Exposure Was Different Too
Light exposure peaked in the morning, not at noon
They sought shade during the hottest, brightest part of the day
Evening light exposure (from fires) was minimal — often under 5 lux (very dim)
This pattern matches modern studies that show morning light exposure helps reset your circadian clock, improves mood, and helps you fall asleep easier at night.
Tip: Get sunlight early in the day, and dim your lights 1–2 hours before bed.
What About Seasonal Changes?
These natural sleepers:
Slept about 1 hour longer in the winter than in the summer
Did not change their wake-up time much
Had later bedtimes in summer, resulting in slightly shorter sleep
This means seasonal changes mattered — but not drastically. In contrast, most of us in modern life maintain a fixed schedule year-round, even if it conflicts with our body’s natural rhythm.
What Does This Mean for You?
This study suggests that:
Humans may not need 8+ hours of sleep — but we do need high-quality, consistent sleep
Sleep timing, light exposure, and temperature matter more than we think
Mimicking aspects of natural sleep — like cooler rooms, earlier light exposure, and later bedtimes — might help with insomnia, fatigue, or jet lag
TL;DR
Hunter-gatherers slept 5.7–7.1 hours/night, mostly at night, with few naps or awakenings
They fell asleep hours after sunset and woke up before sunrise
Cool temperatures and morning light were key sleep regulators
You can improve your sleep by lowering evening light, cooling your room, and getting morning sun
Source:
Yetish G. et al. Natural sleep and its seasonal variations in three pre-industrial societies. Current Biology. 2015; 25(21): 2862–2868.
https://doi.org/10.1016/j.cub.2015.09.046