# Human sleep cycle

**URL:** <https://boards.straightdope.com/t/human-sleep-cycle/289175>\
**Category:** Factual Questions\
**Created:** [February 9, 2005, 10:02am UTC](https://boards.straightdope.com/t/human-sleep-cycle/289175 "2005-02-09T10:02:38Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![drmark2000](https://avatars.discourse-cdn.com/v4/letter/d/a87d85/32.png) [@drmark2000](https://boards.straightdope.com/u/drmark2000)\
**Post date:** [February 9, 2005, 10:02am UTC](https://boards.straightdope.com/t/human-sleep-cycle/289175/1 "2005-02-09T10:02:38Z")

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There was an article in Time from December, 2004, about sleep deprivation in the US, a pandemic problem at this point.

I was disappointed that none of the researchers and other experts cited mentioned what I believe is the most fundamental issue: That we are genetically still wired as hunter-gatherers, mammals who are designed to take our sleep as most (all?) other mammals do, in several blocks throughout the 24-hour day, and probably taking substantially more than the 8 or so hours per day of sleep deemed sufficient by the experts.

Profoundly adaptable creatures that we are, we have progressively imposed a sleep structure that is better suited to the agricultural and industrial ends that our civilization has opted for; but this is inherently unnatural for us and ensures unsatisfactory rest.

Well, that’s what I think, anyway. Any thoughts?

Thanks!

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**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\
**Post date:** [February 9, 2005, 10:12am UTC](https://boards.straightdope.com/t/human-sleep-cycle/289175/2 "2005-02-09T10:12:09Z")

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Firstly I think that since you have no factual question this belongs in IMHO or GD and you shouldn’t be surprised when it’s moved.  
However you’re almost certainly right. Sometimes HGs would stay awake form sunup to sundown, usually when travelling, but as you say the norm was to be active in the early morning and late afternoon and inactive in the middle of the day. This would have been particularly important in the tropics where we evolved.

Almost certainly most of that rest time in the middle of the day wouldn’t have been sleeping but there would have been a siesta.

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**Author:** ![II\_Gyan\_II](https://avatars.discourse-cdn.com/v4/letter/i/bbe5ce/32.png) [@II\_Gyan\_II](https://boards.straightdope.com/u/II_Gyan_II)\
**Post date:** [February 9, 2005, 10:13am UTC](https://boards.straightdope.com/t/human-sleep-cycle/289175/3 "2005-02-09T10:13:09Z")

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Better suited to IMHO or GD.

Here’s a pertinent blog: [Circadiana](http://circadiana.blogspot.com/).