Humans slept in two four-hour blocks, which were separated by a period of wakefulness in the middle of the night lasting an hour or more. During this time some might stay in bed, pray, think about their dreams, or talk with their spouses. Others might get up and do tasks or even visit neighbors before going back to sleep.
Humans evolved near the equator with 12 hours of daylight and 12 hours of darkness.
Our internal body clocks evolved according to our environment at the equator.
Why did our ancestors evolve to have this tow four-hour sleep cycles?
Why do modern humans generally sleep continuously for 8 hours?
Assuming this theory is correct, how would it change our lives and our society?
Do you believe this theory? Why?