According to research by American scientists, published in the American Journal of Physical Anthropology, a person needs adequate sleep less time than other primates.
Researchers David Samson and Charles Khan, studying 30 species of primates, found that all primates, in contrast to the human, allocate to the sleeping 9-15 hours a day. The duration of the rest time depends on a combination of factors that determine the conditions and characteristics of life. Noted that more travelers are in need of night and forest animals.
Confirmed by research calculations, based on the physiology and biological activity, suggest a day's rest from 9.5 hours. However, the normal functioning of the human body provides 7-hour length of sleep. The discrepancy in 36% of the experts explain the development of mankind, which required more time for training, society, transfer of experience. Not the last role was played by the necessity of protection against predators, require special attention. In addition, there is a theory that long sleep contributes to the nightmares.
It is noteworthy that the largest discrepancy in the calculations is typical for a phase of deep sleep – 5.41 hours, compared to 8.41.