Historian A. Roger Ekirch contends that in ancient times, people naturally had two sleeping periods at night- the first starts shortly after sundown and ends in an short break, where people were semi-conscious and would speak to each other about their dreams, or pray, or talk, or have sex. Wikipedia summary here. The second sleep would then end at dawn.

Here's a good NYT article by him.

The issue is, it seems like this is a pretty major claim- that the ancients had multiple sleep periods, yet there doesn't seem to be a lot of coverage of this theory, nor any academic critiques as far as I can find. Is this a legitimate theory, or does it have any possible problems?

  • Don't the Mexicans sleep at around noon (presumably because it's too hot to get anything done)? Here's an interesting document that provides reasons why Siestas are beneficial, and even includes US President Bill Clinton under the "Famous people who napped" heading: siestaawareness.org/pages/siesta-facts.php Jun 13, 2011 at 17:48
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    I think the presence of siestas does show that human beings may be inherently biphasic creatures- that said, I'm not talking about that kind of segmented sleep, but specifically the nocturnal segmented sleep as postulated by Ekirch. Jun 13, 2011 at 19:35
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    Now you've got me wondering if environmental factors such as overall temperatures play a significant role! Is there a difference with natural sleep habits in warmer vs. colder climates, such as near the equator vs. near the north pole? I do find your question very interesting. Jun 13, 2011 at 19:42
  • For what it's worth, I still regularly wake up in the middle of the night. On the contrary, sleeping for 8+ hours straight is quite an achievement IMO. :)
    – deceze
    Jun 14, 2011 at 9:46
  • I remember seeing a show on the History Channel about this. Let me see if I can pull up the source for it. Jun 20, 2011 at 20:21

3 Answers 3


The evidence is quite overwhelming.

See, for example, the Sleep Research section on my website. There, among other items, you will find a direct link to my article, "Sleep We Have Lost," in which I first published this discovery.

there is every reason to believe that segmented sleep, such as many wild animals still exhibit, had long been the natural pattern of our slumber before the modern age, with a provenance as old as humankind.


For the term "first sleep," I have discovered sixty-three references within a total of fifty-eight different sources from the period 1300–1800.


I have also found references to segmented sleep in twelve works of American fiction published during the first half of the nineteenth century. (Full reference: "Sleep We Have Lost: Pre-industrial Slumber in the British Isles," American Historical Review, CV, no.2 (April 2001), 343-387.)

A fuller version of this research can be found in the 2005 book, At Day's Close: Night in Times Past (N.Y., W.W. Norton).

I hope shortly to publish a fresh article that charts in considerable detail the transformation, which occurred in western cultures during the Industrial Revolution, from segmented slumber, the dominant pattern of sleep since time immemorial, to the pattern of consolidated sleep to which we currently aspire if don't always enjoy.

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    Welcome, Professor Ekirch! I am always excited when the original claimant comes here to defend themselves. Please note, perfectly in keeping with the wiki nature of this site, I have made some small edits, including adding links and references to the relevant pages. I also quoted some of the article to give people a better understanding of the nature of your evidence (i.e. large numbers of literary references over the the centuries). I trust I haven't misrepresented your words.
    – Oddthinking
    Oct 14, 2011 at 5:38

Jeff Warren's book "The Head Trip: Adventures on the Wheel of Consciousness" devotes an entire chapter to Ekirch's claim, which he also links to a researcher named Thomas Wehr, of NIMH. The book cites historical references that it claims support the idea, including Robert Louis Stevenson:

There is one stirring hour, unknown to those who dwell in houses, when a wakeful influence goes abroad over the sleeping hemisphere and all the outdoor world are on their feet.

And "the moralist Francis Quarles" :

Let the end of thy first sleep raise thee from thy repose: then hath the body the best temper; then hath thy soul the least encumbrance.”

He quotes anthropologist Carol Worthman, of the Lab for Comparative Human Biology at Emory University, as saying of the subject:

“Yes, this is fully consistent with what I see in non-Western peoples.”

Warren, Jeff (2007). The Head Trip: Adventures on the Wheel of Consciousness Random House. Kindle Edition.

  • +1 Read this book and found it to be a great read. It was the first one to come to mind to answer the OP's question.
    – rajah9
    Oct 14, 2011 at 1:21

If you are interested in sleep patterns in humans, the blog "A Blog Around the Clock" written by Bora Zivkovic is a really good place to start. He makes a lot of the research about circadian rhythms easier to understand for the average person. His post Everything you always wanted to know about sleep (but were afraid to ask) directly addresses this question. I know that this blog post isn't primary research, but circadian rhythms are his specialty and he seems to treat the subject like it's pretty much a given (that is, non-controversial).

Also, if you search pubmed for "chronotype" you will find a lot of articles about individual variation in sleeping patterns, so I think the idea of individual variation is probably well established. Here is an example I couldn't, however, find anything specifically about ancient humans collectively having a couple hour period of wakefulness.

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    Your last sentence is the only one that really answers the question. Consider putting it first. It is helpful if you can find a quote from an expert saying the same thing so we know it isn't just poor luck searching.
    – Oddthinking
    Oct 13, 2011 at 23:58

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