It's more natural to sleep in two four-hour shifts
(NEWSER) - If you often wake up in the middle of the night and can’t fall back asleep right away, you probably call it “insomnia”—but it might actually be more natural than sleeping for eight hours straight. "The dominant pattern of sleep, arguably since time immemorial, was biphasic," a sleep historian tells Life’s Little Mysteries . What that means: Sleep came in two four-hour blocks, with a period of an hour or more in between during which people might pray, think about their dreams, or even visit with neighbors. More»
