Debunked: Popular myth about mandatory sleep duration

Researchers have concluded that the widespread notion of needing exactly eight hours of sleep per night lacks definitive scientific evidence. Studies of modern hunter-gatherer societies show that their sleep duration is comparable to that of people in industrialized countries and sometimes even lower. The review was published in the journal Brain Medicine.

As reported by BAKU.WS, field studies of three hunter-gatherer societies showed that people in these communities sleep an average of 6.4 to 7.1 hours per night. Thus, their sleep is not necessarily longer than that of modern people. According to the scientists, industrialization may have had a greater impact on bedtime and schedule regularity than on overall sleep duration.

The researchers also reconsidered the widespread hypothesis about so-called segmented sleep. According to this theory, people in the past supposedly slept regularly in two separate periods. However, the review authors believe that references to "first sleep" in historical sources could have had different meanings and do not in themselves prove the existence of a universal biphasic sleep pattern.

Additionally, the scientists draw attention to the phenomenon of healthy "short sleepers." Some people carry a rare variant of the DEC2 gene and are able to function normally with less sleep. This suggests that short sleep is not always a sign of a disorder or insufficient rest.

At the same time, the researchers note that sleep quality largely depends on social conditions. Urban noise, artificial lighting, high temperatures, and inadequate housing conditions particularly affect the sleep of residents in disadvantaged neighborhoods.

According to the review authors, instead of striving at all costs to achieve a specific number of hours of sleep, more attention should be paid to schedule regularity and its alignment with the natural light cycle. The scientists also emphasize that there are still insufficient reliable experimental studies directly comparing segmented and continuous sleep under identical conditions.