The notion that eight straight hours of uninterrupted sleep is the “natural” and “healthy” sleep cycle is being called into question by research from one historian and subsequent studies. Historian Roger Ekirch studied writings from ancient times through the pre-industrial age and found that our ancestors slept nightly in two separate periods, separated by one-to-three hours of wakefulness. These periods were known as first sleep and second sleep.
This was the norm, and people spent the waking period between first and second sleep praying, having sex, or even visiting with neighbors. Scholars and poets found the night period a productive time to write.
In one interesting study, Thomas Wehr put eight men in a room for a week where they experienced 14 hours of complete darkness a day, replicating what many of our ancestors experienced before electric lights. The men slept for four hours, followed by about three hours of wakefulness, and then another four-hour period of sleep—replicating the ancient pattern.
These and similar findings have led to greater interest in and attention to segmented sleep. The recent uptick of interest in midday naps at work , and some cultures’ continued tradition of afternoon “siesta” periods, also suggest that segmented sleep may be the more normal human pattern.
What are the psychological and behavioral implications of segmented sleep?
Ekirch noted that in ancient times mid-night wakefulness was seen as a calming time (e.g., for prayer or meditation)—or one for productive activity. I overcame my own insomnia (which was a time of anxiety and worry), by getting up and working for a couple of hours, then returning to a period of deep, “second” sleep.
I once asked a highly-published research psychologist for her recipe for her extraordinary productivity. She mentioned her creation of “little days”—waking up to work intensely from 2:00-4:00 am before returning to a second sleep period. In other words, she had systematized the segmented sleep pattern.
So, either using the waking period productively or as a period of meditation may help. Also, the knowledge that such segmented sleep is in fact “normal” may help calm anxious individuals worried about not getting their 8 straight hours.
It is also interesting to note that in the Wehr study, the men took an average of about two hours to fall asleep, while many of us believe that a good night’s sleep includes falling asleep as soon as our heads hit the pillow.
The causes and consequences of insomnia are many and varied, but it may be helpful for people to know that what most of us consider the “normal” sleep pattern (eight hours of uninterrupted sleep) may not be normal at all.
This knowledge may reduce anxiety and worry and lead to a better sleep experience.