Amount, timing of sleep is less important for health than sticking to routine
Hunter-gatherers and farming villagers who live in worlds without lightbulbs or thermostats sleep slightly less at night than smartphone-toting city slickers, researchers say.
“Contrary to conventional wisdom, people in societies without electricity do not sleep more than those in industrial societies like ours,” says UCLA psychiatrist and sleep researcher Jerome Siegel, who was not involved in the new research.
Different patterns of slumber and wakefulness in each of these groups highlight the flexibility of human sleep — and also point to potential health dangers in how members of Western societies sleep, conclude evolutionary biologist David Samson of Duke University and colleagues. Compared with other primates, human evolution featured a shift toward sleeping more deeply over shorter time periods, providing more time for learning new skills and knowledge as cultures expanded, the researchers propose. Humans also evolved an ability to revise sleep