Humans are way more efficient than other primates in one surprising area–sleep. Whereas we need only around seven hours per night to keep our brains ticking over smoothly, some lazy lemurs and idle macaques need 14 to 17 hours.
Researchers at Duke University carried out a meta study of primate sleeping patterns and found that humans are the world leaders of slumber. Not only do we sleep less, but we get better sleep, despite the other primates not having to endure anxiety dreams about taxes or naked visits to their old high school.
“Humans are unique in having shorter, higher quality sleep,” says study co-author David Samson. The quality comes from our high proportion of REM (Rapid Eye Movement) sleep, which is when brain activity heightens and we dream. REM makes up almost a quarter of our sleep, whereas in some primates it reaches just over five percent. We also spend more time, proportionally, in deep sleep. “Thus,” says the study, “we propose the sleep intensity hypothesis: Early humans experienced selective pressure to fulfill sleep needs in the shortest time possible.”
Even our closest primate brothers, chimpanzees, laze around in trees for an average of 11.5 hours per night, a length of sleep that makes even human teenagers look like harried world leaders. The study’s authors speculate that once humans stopped sleeping in the safety of trees, we evolved to spend less time laying in a vulnerable sleep state. Samson says that “shorter sleep also freed up time that could be devoted to other things, like learning new skills and forging social bonds, while deeper sleep helped to cement those skills, sharpen memory and boost brainpower.”
Next time you’re struggling to get out of bed to drive an hour through hammering rain and hellish commuter traffic to reach the office, remember to marvel at the efficiency of our human sleep patterns, and try not to think about those southern pig-tailed macaques, which will be snoozing in a tree for another seven hours before they even think about getting up.