Compared with other mammals and primates, humans need far less sleep.
Humans get an average of seven hours a night, according to a study from Duke University in Durham, North Carolina. Other species, such as southern pig-tailed macaques and gray mouse lemurs, need as many as 14 to 17 hours of sleep.
Researchers found that our sleep is more efficient, meaning we spend a smaller proportion of time in the light stages of sleep and more in the deeper stages. For example, we spend nearly 25% of our time in the dream state called rapid eye movement sleep. In many other primates, REM sleep barely climbs above 5%.
“Humans are unique in having shorter, higher quality sleep,” says study co-author David Samson, a postdoctoral associate in Duke’s Department of Evolutionary Anthropology.
Researchers attribute the shift toward shorter, more efficient sleep in part to the transition from sleeping in the trees, as our early human ancestors likely did, to sleeping on the ground—and on quality mattresses—as we do today. The findings appear in the journal Evolutionary Anthropology.
