Perhaps sleep problems are simply part of the evolutionary past
Today many people suffer from sleep problems. Poor sleep is often seen as a result of hectic modern life. However, current research results now indicate that a particularly light sleep or waking up several times during the night is a survival mechanism that is supposed to protect against nighttime threats.
Scientists at Duke University in North Carolina and the University of Nevada in Las Vegas found that nighttime difficulty sleeping is a survival mechanism that protects people from potential nighttime threats, the press release said the results of the current study.
Researchers study sleeping patterns of a native tribe in Tanzania
In their current study, the researchers examined the sleep patterns of people from a so-called hunter-gatherer tribe in northern Tanzania. The experts were able to determine that frequent waking up at night and different sleeping plans between old and young people ensure that in most cases at least one tribe member is always awake.
Bedtime of tribal members very low
For a period of three weeks, there were only 18 minutes in which all 33 members of the tribe slept at the same time, the authors explain. When we observed the population, we noticed that the total sleep time of the tribal members is quite low. We live much more safely in our western society, which is why we actually sleep better, explains author David Samson from Duke University.
Those affected less often suffered from sleep problems
Although the people of the tribe generally sleep less, those affected suffered less from sleep problems and insomnia, which are particularly widespread among older people from modern industrial nations, the scientists say.
Experts examined the Hadza tribe in northern Tanzania
The study focused on the so-called Hadza in northern Tanzania, which live in groups of twenty to thirty people. During the day, men and women go their separate ways to collect tubers, berries and honey and hunt animals, the experts explain. In the evening, all members of the tribe meet again. The Hadza often all sleep together in their huts made of grass and branches.
Study provides insight into human evolution
The Hadza show us an important part of human evolutionary history. They live in a style that is most similar to our past, explains author Alyssa Crittenden from the University of Nevada. For example, they sleep on the floor and have no synthetic lighting or regulated indoor climate.
Doctors examine the sleeping habits of 33 participants
The researchers tracked the sleep patterns of 33 healthy Hadza men and women. They wore watch-like devices on their wrists for twenty days. So the movements during the night should be recorded. Usually, the participants woke up several times a night, for example to turn around, smoke or take care of crying babies, the scientists explain.
Variation and flexibility in human sleep is normal
When people are in a lighter state of sleep, they are more alert to all kinds of threats in the area, explains author Charlie Nunn of Duke University. On average, more than a third of the group was awake at all times or fell asleep only slightly. The results show that variation and flexibility are completely normal in human sleep, author Samson adds.
What sleeping habits did the participants have?
Previous studies have found similar patterns in birds, mice and other animals. The phenomenon has now been observed for the first time in humans, say the doctors. On average, the participants went to bed shortly after 10 p.m. and woke up at 7 a.m. However, there were some people who were already asleep at 8 p.m. and woke up around 6 a.m. These were mostly older participants. Younger participants, on the other hand, usually slept from 11 p.m. to 8 a.m., the experts add.
Are the sleep problems of older people often not really disturbances?
The authors contend that the different orientations of sleeping habits of adolescents and the elderly could be an evolutionary adjustment that kept our ancestors safe when sleeping in mixed age groups. A lot of older people go to doctors these days and complain that they wake up early and can't go back to sleep, says Nunn. However, there are probably often no health problems at all and perhaps some of the so-called sleep disorders are only a relic of the evolutionary past, which was originally beneficial for humans, the scientists explain. (as)