Struggling to get a full 8 hours in at night? There may be a scientific reason behind your restlessness.
Scientists have found that split sleeping, or sleeping for two shorter periods rather than a solid span of time, used to be how humans got shuteye.
Dr. Melinda Jackson of RMIT University in the UK says that our notion of a “good night’s sleep” is a rather new idea for humans. This may explain why around a third of the population has trouble sleeping. These problems could be biological results of our old sleeping habits, and our bodies are just trying to wake us up in the middle of our two sleep periods.
Why did our ancestors choose this sleep pattern? For one, the split sleeping may increase our awareness during the day. It also allows for greater flexibility for daily tasks. Since there was no set bedtime, they were able to finish what was needed, sleep when they were tired, and resume the cycle once more, finally awakening for the day around dawn.
Researchers say that there are many references made to two distinct sleep periods in ancient texts, but don’t let that confuse you: Split sleeping is not a thing of ancient history. It’s known that preindustrial societies in Europe used split sleeping, normally allowing for 13 hours between sleeping periods. Historian A. Roger Ekirch found that first and second sleep, as it was called, began to die out in Europe in the late 17 th century and took the next 200 to do so in the rest of the world. Around this same time came the idea of sleep maintenance, or the importance of sleeping throughout the entire night. This extra pressure may have added to preexisting anxiety about sleep and ended up making things worse.
To determine what sleeping pattern humans gravitate to naturally, psychiatrist Thomas Wehr conducted an experiment in the 1990s. His subjects were left in total darkness for 14 hours every day, instead of the 8 hours that we are accustomed to in everyday life. This prolonged darkness occurred for a month. Although it did take some time for sleep patterns to emerge, by the fourth week there were clearly two phases of sleep. The first sleep was for around four hours, and then subjects woke up for one to three hours. They fell asleep for another four hours shortly after. This research suggests that our internal clocks are pushing for two sleep periods and the issues we face with sleeping are a result of our fight against our bodies.
Biphasic sleeping, an evolution of split sleeping, is still common today. Spaniards still use a form of split sleeping with their “siesta.” You may also be familiar with the “postlunch dip” that is a physical side effect of our body’s internal clocks and causes a decrease in alertness.
Information from: DailyMail.co.uk