Like a mantra we heard almost throughtout our entire childhood and adolescence that we should sleep 8 straight hours in order to get a good rest and be prepared for the new day. I remember my parents having trouble in putting us to sleep every night, specially on weekend nights when there were movies and cartoons all day long that kept us fully energized and motivated, with testosterone levels high enough to be fully awake and vivid to skip beds!! Well, apparently, the eight hour scheme isnn't entirely normal nor a natural way to rest. Check out this article:
In the early 1990s, psychiatrist Thomas Wehr conducted an experiment in which a group of people were plunged into darkness for 14 hours every day for a month.
It took some time for their sleep to regulate but by the fourth week the subjects had settled into a very distinct sleeping pattern. They slept first for four hours, then woke for one or two hours before falling into a second four-hour sleep.
Though sleep scientists were impressed by the study, among the general public the idea that we must sleep for eight consecutive hours persists.
In 2001, historian Roger Ekirch of Virginia Tech published a seminal paper, drawn from 16 years of research, revealing a wealth of historical evidence that humans used to sleep in two distinct chunks.
His book At Day's Close: Night in Times Past, published four years later, unearths more than 500 references to a segmented sleeping pattern - in diaries, court records, medical books and literature, from Homer's Odyssey to an anthropological account of modern tribes in Nigeria.