A person spends a third of his life in a dream. This state is necessary for restoration of strength, rest, as well as for the normal functioning of the psyche - more precisely, the sphere of the unconscious. Animals also need sleep.
The normal duration of sleep is an individual phenomenon, and yet certain trends can be traced. The duration of sleep varies from species to species, and within one species varies depending on age.
People
Sleep duration in humans decreases with age.
The fetus spends the most time in a dream in the womb - from 85% to 90% of the time. With the help of encephalograms, scientists have established that in intrauterine life there is a different ratio of the phases of REM and slow sleep: each of them takes about 50% of the time, while in adults, the duration of REM sleep is less than 20%.
Newborns also sleep a lot - in general, up to 18 hours a day. By 3-4 months, the duration of sleep decreases to 17 hours, by 5-6 - up to 16, by 7-9 - up to 15, and one-year-old children sleep no more than 15 hours. From a year to one and a half years, the child sleeps 10-11 hours at night and twice in the daytime for 1, 5-2 hours in the afternoon, after one and a half years, one daytime sleep remains. After 7 years, children stop sleeping during the day, and sleep 8-9 hours at night.
Sleep duration decreases in adulthood as well. British researchers from the University of Surrey found that 20-30 year old people sleep on average 7, 23 hours, 40-55 year olds - 6, 83, and people over 60 years old - 6, 51.
Thus, the younger a person is, the more he sleeps.
Animals
Speaking about the duration of sleep in various animals, one should not remember bears, hedgehogs and other animals that hibernate for the winter. Hibernation, which is scientifically called hibernation, differs from sleep: the body temperature of the animal decreases by several degrees, the heartbeat, respiration and other physiological processes slow down - this does not happen during normal sleep. It's about daily sleep, not hibernation.
The cat is traditionally considered the "champion" of sleep duration among the people. It is no coincidence that "kitty-kitty-cat" appears so often in lullabies: it was believed that this animal should "teach" a child to sleep.
The true record holder for the duration of sleep was established by the Swiss zoologist P. Hodiger. It is noteworthy that the "champion" was a representative of the feline family - the African lion. This predator sleeps up to 20 hours a day. Leo can afford such a long sleep - after all, he has practically no natural enemies.
The second place is occupied by sloths - animals from the order of primates living in Central and South America. They sleep 15 to 18 hours a day.
