Sleep Science: Why You Can’t Stay Asleep at Night

Source: iStock

Source: iStock

Waking up in the middle of the night can be a stressor for even the most laid-back people. Your mind starts wandering, thinking of how tired you’ll be in the morning if you can’t get some more decent shut-eye. When rolling over or counting livestock doesn’t work, slight anxiety can turn into full-fledged worry — worry that spills over to every issue in your life that’s now contributing to your insomnia.

Worry and stress are definitely the world’s best anti-sleeping drugs. But just because you wake up in the middle of the night and can’t get back to sleep doesn’t mean it’s necessarily a bad thing. In fact, waking up for an hour (or even a few) used to be common, and was viewed as natural, not a problem. Several studies show that the definition of “a good night’s sleep” is completely dependent upon what century you lived in, and look very different from our current standard of one eight-hour block.

The unnatural 8-hour sleep cycle

The eight-hour block of uninterrupted slumber is a convention of modern times. In fact, up until the 1900s, there were other schools of thought about what rest looked like. In the 1980s and 1990s, history professor Roger Ekirch started to notice references of unique sleep patterns in his collection of texts. “First sleep” and “second sleep” were common occurrences, and it served as a signal that sleep used to happen in distinct chunks. Ekirch later went on to write a book called At Day’s Close: Night in Times Past that described how sleep patterns used to be four hours at a time, with a one- or two-hour break in between the first and second segments.

In the same way an insomniac today scans Facebook or picks through their latest book of the month, the waking hours of the night were filled with activity, Ekirch found. Generations of people who depended on sunlight for work went to sleep when night fell, then awoke around midnight or so. They filled an hour or so with reading, prayer, visiting neighbors, or sex. Then they fell asleep for another four hours before waking up to begin the next day, often at daybreak or soon after.

Source: iStock

Source: iStock

Ekirch’s book contains more than 500 historical mentions of these two sleep divisions, in works including Homer’s Odyssey and Chaucer’s Canterbury Tales. “It’s not just the number of references – it is the way they refer to it, as if it was common knowledge,” Ekirch told BBC. Those references faded by the late 1800s, though, and by 1920 were almost completely obsolete. The eight-hour block of sleep became more common.

Ekirch and other scholars attribute the shift to electricity. Before street lamps and light bulbs were common, night was often associated with crime, fear, and other not-so-wonderful things. As artificial light became a staple in every household, people began staying up later, thus squeezing out the time for the waking hours in the middle of the night.

In the absence of light bulbs, humans surprisingly fall back into segmented sleep without much prompting. Researcher and psychiatrist Thomas Wehr found that when people are exposed to 10 hours of light instead of 16 (essentially, relying on the sun instead of electricity), they naturally start to sleep for a few hours, wake up for one to three, and fall back asleep again.

You might not need that sleep aid

In today’s culture, sleeping through the whole night is considered to be healthy. Waking up in the dead of night is not. And if you complain to your doctor, you’ll likely walk away with a slip for Ambien or an equivalent. We worship the eight-hour sleep cycle, and much of our lives function on the idea of an uninterrupted chunk of rest. Finding another two hours to wake up in the middle probably isn’t possible, especially with our bodies’ adaptations to modern things like light bulbs and our culture’s rigid 9 to 5 schedules.

Don’t get us wrong — sleep disorders are a very real thing, and in many cases do require the guidance of a professional. But if you’re waking up occasionally and can’t get back to sleep, read a book. If you’re lucky enough that your tossing also woke your partner, experiment a little with mid-night sex. If you’re not typically an insomniac, chances are you’ll be ready to go back to sleep in an hour or so. Some people claim their most creative hours are still sometime in the middle of the night. And don’t worry about that lost shut-eye — generations before you didn’t just survive with a sleep break, they organized their lives around it.

Follow Nikelle on Twitter @Nikelle_CS

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