The myth of the eighteight-hour sleep 22 February 2012 Last updated at 16:58 GMT http://www.bbc.co.uk/news/magazine-16964783
By Stephanie HegartyBBC World Service
We often worry about lying awake in the middle of the night - but it could be good for you. A growing body of evidence from both science and history suggests that the eight-hour sleep may be unnatural. 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 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 t he 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 fr om 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.
Roger Ekirch says this 1595 engraving by Jan Saenredam is evidence of activity at night
Much like the experience of Wehr's W ehr's subjects, these references describe a first sleep which began about two hours after dusk, followed by waking period of one or two t wo hours and then a second sleep. "It's not just the number of references - it is the way they refer to it, as if it was common knowledge," Ekirch says. During this waking period people were quite active. They often got up, went to the toilet or smoked tobacco and some even visited neighbours. Most people stayed in bed, read, wrote and often prayed. Countless prayer manuals from the late 15th Century offered special prayers for the hours in between sleeps. And these hours weren't entirely solitary - people often chatted to bed-fellows or had sex. A doctor's manual from 16th Century France even advised couples that the best time to conceive was not at the end of a long day's labour but "after the first sleep", when "they have more enjoyment" and "do it better". Ekirch found that references to the first and second sleep started star ted to disappear during the late 17th Century. This started among the urban upper classes in northern Europe and over the course of the next 200 years filtered down to the rest of Western society. By the 1920s the idea of a first and second sleep had receded r eceded entirely from our social consciousness.
When segmented sleep was the norm
"He knew this, even in the horror with which he started from his first sleep, and threw up the window to dispel it by the presence of some object, beyond the room, which had not been, as it were, the witness of his dream." Charles Dickens, Barnaby Rudge (1840) "Don Quixote followed nature, and being satisfied with his first sleep, did not solicit more. As for Sancho, he never wanted a second, for the first lasted him from night to morning." Miguel Cervantes, Don Quixote (1615) "And at the wakening of your first sleepe You shall have a hott drinke made, And at the wakening of your next sleepe Your sorrowes will have a slake." Early English ballad, Old Robin of Portingale The Tiv tribe in Nigeria employ the terms "first sleep" and "second sleep" to refer to specific periods of the night Source: Roger Ekirch
Roger Ekirch's website
He attributes the initial shift to improvements in street lighting, domestic lighting and a surge in coffee houses - which were sometimes open all night. As the night became a place for legitimate activity and as that activity increased, the length of time people could dedicate to rest dwindled. In his new book, Evening's Empire, historian Craig Koslofsky puts forward an account of how this happened. "Associations with night before the 17th Century were not good," he says. The night was a place populated by people of disrepute - criminals, prostitutes and drunks. "Even the wealthy, who could afford candlelight, had better things to spend their money on. There was no prestige or social value associated with staying up all night." That changed in the wake of the Reformation and the counter-Reformation. Protestants and Catholics became accustomed to holding secret services at night, during periods of persecution. If earlier the night had belonged to reprobates, now respectable people became accustomed to exploiting the hours of darkness. This trend migrated to the social sphere too, but only for those who could afford to live by candlelight. With the advent of street lighting, however, socialising at night began to filter down through the classes. In 1667, Paris became the first city in the world to light its streets, using wax candles in glass lamps. It was followed by Lille in the same year and Amsterdam two years later, where a much more efficient oil-powered lamp was developed. London didn't join their ranks until 1684 but by the end of the century, c entury, more than 50 of Europe's major towns and cities were lit at night. Night became fashionable and spending hours lying in bed was considered a waste of time.
A small city like Leipzig in central Germany employed 100 men to tend to 700 lamps
"People were becoming increasingly time-conscious and sensitive to efficiency, certainly before the 19th Century," says Roger R oger Ekirch. "But the industrial revolution intensified that attitude by leaps and bounds." Strong evidence of this shifting attitude attit ude is contained in a medical journal from 1829 which urged parents to force their children out of a pattern of first and second sleep. "If no disease or accident there intervene, they will need no further repose than that obtained in their first sleep, which custom will have caused to terminate by itself just at the usual hour. "And then, if they turn upon their ear to take a second nap, they will be taught to look upon it as an intemperance not at all redounding to their credit." Today, most people seem to have adapted quite well to the eight-hour sleep, but Ekirch believes many sleeping problems may have roots in the human body's natural preference for segmented sleep as well as the ubiquity of artificial light. This could be the root of a condition called sleep maintenance insomnia, where people wake during the night and have trouble getting back to sleep, he suggests. The condition first appears in literature at the end of the 19th Century, at the same time as accounts of segmented sleep disappear. "For most of evolution we slept a certain way," says sleep psychologist Gregg Jacobs. "Waking up during the night is part of normal human physiology." The idea that we must sleep in a consolidated block could be damaging, he says, if it makes people who wake up at night anxious, as this anxiety can itself prohibit sleeps and is likely to seep into waking life too.
Stages of sleep
Every 60-100 minutes we go through a cycle of four stages of sleep
Stage 1 is a drowsy, relaxed state between being awake and sleeping - breathing slows, muscles relax, heart rate drops
Stage 2 is slightly deeper sleep - you may feel awake and this means that, on many nights, you may be asleep and not know it
Stage 3 and Stage 4, or Deep Sleep - it is very hard to wake up from Deep Sleep because this is when there is the lowest amount of activity in your body
After Deep Sleep, we go back to Stage Stage 2 for a few minutes, and then then enter Dream Sleep also called REM (rapid eye movement) m ovement) sleep - which, as its name suggests, is when you dream In a full sleep cycle, a person goes through all the stages of sleep from one to four, then back down through stages three and two, before entering dream sleep Source: Gregg Jacobs Gregg Jacobs' site - CBT for Insomnia
Russell Foster, a professor of circadian [body clock] neuroscience at Oxford, shares this point of view. "Many people wake up at night and panic," he says. "I tell them that what they are experiencing is a throwback to the bi-modal sleep pattern." But the majority of doctors still fail to acknowledge that a consolidated eight-hour sleep may be unnatural. "Over 30% of the medical problems that doctors are faced with stem directly or indirectly from sleep. But sleep has been ignored ig nored in medical training and there are very few centres where sleep is studied," he says. Jacobs suggests that the waking period between sleeps, when people were forced into periods of rest and relaxation, could have ha ve played an important part in the human capacity to regulate stress naturally. In many historic accounts, Ekirch found that people used the time to meditate on their dreams. "Today we spend less time doing those things," says Dr Jacobs. "It's not a coincidence that, in modern life, the number of people who report anxiety, stress, depression, alcoholism and drug abuse has gone up." So the next time you wake up in the middle of the night, think of your pre-industrial ancestors and relax. Lying awake could be good for you. Craig Koslofsky and Russell Foster appeared on The Forum from the BBC World Service.. Listen to the programme here Service here..
Comments +2
Comment number 180. 180.
CarolinePJ 22ND FEBRUARY 2012 - 17:47
If I don't get my second sleep - usually from about 3-7am - I feel completely drunk/hungover for the rest of the day, even without alcohol! The liver is most active in repairing and filtering between 2 and 4 am. So if you are going to have two sleeps better to wake up around midnight, or before, so you give your body a chance to recover from the previous day!
+4
Comment number 163. 163. bbcrdr 22ND FEBRUARY 2012 - 16:53
"In1667, Paris became the first city in the world to light its streets" Non-sense! The Muslims of Spain were way ahead of their time, having developed street lighting when all of Europe was in absolute darkness!
+13
Comment number 162. 162. Pdibbs 22ND FEBRUARY 2012 - 16:57
Anyone who has a newborn newborn child knows what what it's like to sleep in 4-hour bursts. I've never heard a single one say something positive about it ;)
+3
Comment number 156. 156. Bottski 22ND FEBRUARY 2012 - 16:48
Your body works on ~29 hour day so we are constantly adjusting our body clocks. As a shift worker I pay attention to my circadian rhythm and sleep in multiples of 90 minutes as this is the natural routine for a body from light sleep to deep sleep and back again. It takes me around 15 minutes to get to sleep so i go to bed 7h45m before I need to get up. Try it, it takes a while to feel the benefit
+5
Comment number 143. 143. Lavistas 22ND FEBRUARY 2012 - 16:29
I worked as a baker for several years and simply got used to sleeping two 4 hour periods every day. 11-3 and 1-5. Once I stopped, I quickly fell back into an 8 hour an night pattern. My dad
was a baker all his life and even when he stopped, he would still get up at 4am. You can get used to it - as long as your body gets the chance to rest and recuperate.
+2
Comment number 77. 77. NakedLunch 22ND FEBRUARY 2012 - 14:38
Waking up from REM sleep in the night is one of the largest f actors which contribute to hallucinations. Perhaps when added to this information this would explain the greater level of sightings of ghosts and malevolent spirits?
+5
Comment number 60. 60. willtee 22ND FEBRUARY 2012 - 14:15
This pattern is also borne out by the monastic day, which contained the 'night hours'. To this day, for instance, Carthusian monks sleep from 7.30 pm to 11.30 pm then get up, go to church for a couple of hours and go back to bed at about 2.30 getting up again at 6.30 - textbook first and second sleeps of four hours each.
+9
Comment number 52. 52. Fred Dines 22ND FEBRUARY 2012 - 14:07
Well that makes sense of my sleeping pattern. I always wake up after 4 hours sleep. I used to lay awake and become frustrated. For some time now I have made a habit of making a cup of tea and reading or browsing the news feeds for half an hour to an hour then going back to bed at the point of feeling drowsy. Works for me and the second sleep is the most refreshing.
