Historical Sleep Patterns: Two Shifts Were Normal, Not a Disorder
Recent studies have shed light on the sleep habits of our ancestors, revealing that sleeping in two distinct shifts was a common and natural practice, rather than a sign of disorder as previously thought. This biphasic sleep pattern, where individuals would sleep for a few hours, wake for a period of activity, and then return to sleep, was widespread in pre-industrial societies.
The Evidence from Historical Records
Researchers have analyzed diaries, medical texts, and literature from centuries past, finding numerous references to segmented sleep. For example, in the 17th century, it was typical for people to have a "first sleep" after dusk, wake around midnight for an hour or two of quiet activities like reading or socializing, and then enjoy a "second sleep" until morning. This pattern was considered normal and even beneficial for health and productivity.
Contrast with Modern Sleep Norms: Today, uninterrupted sleep of 7-9 hours is often promoted as the ideal, leading to concerns when individuals experience nighttime awakenings. However, historical data suggests that such awakenings are not necessarily indicative of insomnia or other sleep disorders, but rather a remnant of our ancestral rhythms.
Implications for Modern Sleep Science
This discovery challenges contemporary views on sleep health. Experts now argue that biphasic sleep may be more aligned with human biology, as it allows for periods of rest and activity that match natural circadian rhythms. In fact, some cultures and individuals still practice segmented sleep today, reporting increased alertness and well-being.
- Historical sleep patterns included a first sleep and a second sleep with a wakeful period in between.
- Modern sleep disorders may be overdiagnosed due to a misunderstanding of natural sleep variations.
- Adopting flexible sleep schedules could improve health outcomes for some people.
Further research is needed to explore how these findings can inform sleep therapy and public health recommendations. By recognizing that two shifts of sleep were once normal, we can reduce stigma around nighttime awakenings and promote more personalized approaches to sleep wellness.
