(Photo: John Lambert Pearson)
Do you miss the days when we lived in trees, ate fresh fruit, and slept whenever we wanted? We can't go back to last week, but we can make lifestyle choices now. Perhaps they will be informed by the results of a new study published in Evolutionary Anthropology. The authors discovered that among all primates, humans sleep the least. Esther Inglis-Arkell explains at Gizmodo:
[...] humans get about seven hours of sleep per night. That’s less than half the time that animals like mouse lemurs devote to sleeping. Some primates sleep up to 17 hours a day. And it holds true in both highly technological societies and those that steer clear of technology and keep to cycles of natural light.
We do, however, dream more than other primates:
When humans do sleep, they’re in REM (random eye movement) sleep for about 25% of the time. REM sleep is associated with dreams. Although other primates may dream, researchers estimate that they spend only about five percent of their time in REM sleep.
Why are we different? Perhaps in our evolutionary development, we found that sleep deprived us of social interaction and exposed us to threats:
According to the study authors, once humans moved from the trees to the ground, there were probably three main selective pressures keeping them awake: “increased predation risk in terrestrial environments, threats from intergroup conflict, and benefits arising from increased social interaction.”