Wednesday, February 22, 2012

The 8-Hour Chunk Of Sleep May be Unnatural

Roger Ekirch says this 1595 engraving
by Jan Saenredam is evidence of activity at night
The Myth Of The Eight-Hour Sleep, BBC, 22 February 2011

Do you wake in the middle of the night and have difficulty returning to sleep? Historian Roger Ekirch says that before the Industrial Revolution, two chunks of sleep with a 1-to-2-hour period of wakefulness between was the norm.
"His book At Day's Close: Night in Times Past, 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.

These references describe a first sleep which began about two hours after dusk, followed by waking period of one or two hours and then a second sleep.

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."
After the Industrial Revolution, we became more time-conscious and set aside the second sleep - as well we could since light was available throughout the night:
"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."
It may have come at a cost to health:
"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."

Jacobs suggests that the waking period between sleeps, when people were forced into periods of rest and relaxation, could have played an important part in the human capacity to regulate stress naturally.

"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."
The article ends with: "Lying awake could be good for you."


preserve said...

The "not a coincidence" part is humorous.

From anecdotal observations, I'd say most people I know that can't sleep 6 hours in a night have some form of stress, depression, anxiety, or substance related problem.

I believe there are also a few people studying the effects of electricity and lighting that caused an increase in stress a result of lack of sleep.

Perovskia said...

I've also read recently that they think 4 hours sleep could be as beneficial to 8 hours sleep. It's interesting, because I feel just as well after 4 hours, as compared to 8.

Perhaps that's what they're also suggesting here?

Bix said...

After midnight, we're gonna let it all hang down.
After midnight, we're gonna chug-a-lug and shout.
We're gonna stimulate some action;
We're gonna get some satisfaction.
We're gonna find out what it is all about.
After midnight...

Bix said...

Sorry. I think my astrocytes are overcompensating.

Ronald said...

I have often been plagued with what I termed middle-of-the-night wakefulness. I would wake up and be filled with anxiety that I was suffering from insomnia and wouldn't be able to go back to sleep then be exhausted the next day and not be able to surf the web effectively. Discovering that having two sleep periods is normal relieves me. I usually did fall back to sleep, though not always, and the relief I feel has prompted me to go back to bed for a few hours.

Bix said...

Ronald, you too?

I'm tempted to get up and make beans.

caulfieldkid said...

I don't know. I don't have trouble sleeping through the night. If I've been physically exerting myself, it's not hard for me to sleep for a solid 9 hours (Incidentally, I've never napped well. They even let me stay up and color during preschool).

Someone in the article's comments also mentioned moms with infants. Being from a household that has finally emerged from ~5 years of sporadic sleep patterns, I'll stick with a solid 6-8 (not to imply I was the primary get-up-with-infant-er. My wife is gracious, and welcomes long periods of sleep/rest).

I wonder how much of it is just convention. Sorry, but 500 examples over hundreds of years isn't an impressive data set to me. At present, I'm more inclined to agree with the claim that "the 8-hour chunk of sleep may not be the only way to do it."