Scientists dispelled the myth of the eight natural sleep

Primitive hunter-gatherers slept as little as modern people suffering from insomnia, artificial light and night-time entertainment. US scientists have disproved the myth that the "natural" state of a person retiring at sunset and get up at dawn. A study on the subject published in the journal Current Biology.

Anthropologists have worked with three groups of modern hunter-gatherers, traditional lifestyles - Bolivian tsimane, Namibian Bushmen and Tanzanian Hadza. Total scientists recorded especially sleep 94 people. Since the lifestyle of these tribes has changed relatively little over the past few thousand years, their habits considered an indirect indicator of sleep practices of primitive people.

After several years of research, scientists have found that sleep in tsimane, Hadza Bushmen and, despite all the genetic, historical and geographical differences between them, subject to a strikingly similar laws. On average, they sleep less than six and a half hours (for comparison - the inhabitants of big cities in Europe and the United States the average allotment to sleep seven or eight hours).

None of the study participants went to bed after dark - just like in the cities with artificial lighting. Within three hours after sunset hunter-gatherers cook, dinner, prepared arrows and making plans for the next day. In addition, the majority of the Hadza, tsimane Bushmen and woke before dawn.

A number of medical studies have shown that modern industrial society representatives often feel sleepy in the middle of the day - which gave ground for the theories of the natural sleep-afternoon, the possibility of which was suppressed by civilization. However, hunters and gatherers almost never went to bed in the afternoon.

The only significant difference between the archaic tribes and residents of big cities - the first almost do not suffer from insomnia. Only 1.5-2.5 percent of hunter-gatherers could not sleep at night more often than once a year. In languages ​​tsimane dignity and even no word for insomnia. For comparison, suffer from chronic insomnia from 10 to 30 percent of representatives of industrial societies.

The number of hours of sleep in hunter-gatherers changed mainly depending on ambient temperature - in the winter they sleep on average an hour longer than the summer. In modern conditions the most important regulator of sleep off (due to heating), and its return can help in the fight against insomnia, the researchers note.

In 2014, another group of scientists found that the nightly conversations around the campfire played a crucial role in the evolution of human culture. Evening talks, as opposed to the daily, focused on those with whom the Bushmen do not touch in everyday life - the spirits, ancestors and distant tribes. In addition, the campfire telling cautionary tales and myths, bringing up members of the tribe in the correct behavior and respect for social norms.