The idea that adults need eight hours of sleep per night is associated with the popularization, in the 19th century, of dividing the day into eight hours of work, eight of leisure, and eight of rest. This belief became widely spread, but researchers began to question its scientific basis.
To better understand sleep patterns in societies less exposed to industrialization and artificial lighting, researchers decided to study traditional subsistence populations, which maintain lifestyles closer to those of our ancestors.
In a study published in 2015 in the journal Current Biology, the sleep patterns of the Hadza in Tanzania, the San in Namibia, and the Tsimane in Bolivia were analyzed. These three populations were chosen because they live in non-industrialized environments.
The participants in these groups slept on average about 6.4 hours per night, a value significantly lower than the traditionally recommended eight hours.
