Is the Eight Hour Night Really a Myth?

When it comes to sleep, we’re doing it wrong.

At least, that’s the allegation of some historians and sleep researchers who suggest that bedding down for seven to eight consecutive hours of rest is unnatural.

I find this interesting on a personal level, as I have no problems sleeping through the night.

Yet their argument –and its supporting evidence– is compelling. Drawn from historical records and clinical trials, a new picture is emerging that is at odds with the modern model of healthy sleep.

When is an Insomniac not an Insomniac?

Currently, millions of people suffer with middle-of-the-night insomnia; 38% of Americans report waking up “a lot” in the middle of the night. This usually temporary condition can be treated clinically with pharmaceuticals and cognitive behavior therapy, yet, unfortunately, is more likely to be self-treated with alcohol.

But according to sleep psychologist Rubin Naiman in his book Healing Night, waking up in the middle of the night may actually be natural and healthy for some individuals, rather than a sign of poor sleep.

As such, some cases of insomnia may be more about our cultural attitude towards middle-of-the-night awakening, not a personal failing.  In fact, one of the most effective treatments for insomnia is all about changing one’s perspective and perceptions about time spent asleep and time spent awake.

Clinical evidence also suggests that we modern, hyper-connected humans regress towards a more segmented–but not fragmented or shortened– sleeping style when given the chance.

An often-cited study by psychiatrist Thomas Wehr showed that when subjects spent 14 hours a night in darkness for a period of a month, their sleep schedule took a new formation by the fourth week. Rather than getting all their sleep at once, they began sleeping for three to four hours, awakening for an hour or two, and then going back to sleep for another few hours.

Anthropologists, such as Carol Worthman and Melissa Melby, argue that this industrialized way of a single block of sleep at night is a total aberration, especially when one examines the sleeping patterns and habits of non-industrialized societies.

So what do Wehr’s subjects, our pre-industrial ancestors, and contemporary indigenous societies around the globe today have in common besides a segmented sleeping pattern?

The lack of artificial lighting.

Gimme that Old-Fashioned Sleep

Sleep historians have compiled massive evidence that before the 19th century, most of us used to sleep in two separate chunks during the night up until the beginnings of their industrial ages.

Known as “first sleep” and “second sleep,” these periods of rest were divided by a relaxing period of wakefulness in the middle of the night.  Early Christian monastic orders may have made use of this natural break when codifying the Hours of Divine Office, having their members wake up during the middle of the night to say prayers.

Yet how did we get from “it’s okay to wake up & work in the middle of the night” to ” I can’t stay asleep–there must be something wrong?”

Funny story, actually.

A Brief History of Night Light

In Evening’s Empire, historian Craig Koslofsky reconstructs how Europeans lost their taste for this middle of the night break. Candles were expensive (and took ages to make), so it was mainly the rich who could afford them to use every night. But over time, mayors and rulers began to insist upon street lighting in cities, making social outings at night much safer, less suspect, and, consequently, more popular.

Add to that massive changes in industrialization and the new obsession with capitalism and productivity, and the deal was done. Medical journals start to recommend that middle-of-the-night awakenings are inefficient, a waste of time, and folks begin to follow suit, reflecting this new attitude that quiet awake time at night is undesirable

Interestingly enough, complaints about insomnia increased in the 19th century just as medical accounts of segmented sleep disappeared.

Told you it was a funny story.

Messing with the Biological Can of WTF

Today, chronobiologists and other sleep scientists have largely proven the theory that artificial light fools with natural sleep wake cycles. Melatonin is chief hormone disrupted by artificial light, delaying the urge to sleep after the sun goes down.

On top of that, the effects of artificial light seem to linger. Sleep scientist (and Zeo SAB member) Charles A. Czeisler noted that melatonin release is significantly delayed if bright indoor lighting is applied after dark for a period of 5 nights versus 2 nights in

So our habits actually cement new sleep-wake patterns through consistent melatonin delay, giving further clinical credence to historians’ claims that the modern era has successfully trumped the solar day with cities (and inhabitants) that never sleep.

Melatonin isn’t the only hormone affected by light and darkness. Wehr found that his subjects who were immersed in darkness and who woke up after a few hours of sleep had high levels of prolactin – a hormone associated with sexual fulfillment and satisfaction – in their blood.   According to historian Roger Ekirch, medical sources from the 18th century also allude to this period as optimal for sexual relations and fertility.

Are we really doing it wrong?

Maybe, especially when we consider that many of us are not even getting enough sleep each night,  yet it’s important to remember that sleep comes to us all uniquely despite these overt cultural values and biological pulls.

It’s also important to remember that, as far as we can tell, our pre-industrialized ancestors got enough sleep each night — and that research has shown that “enough sleep” appears to be at least 7 hours for a healthy body.  So while the 8, uninterrupted hours, of sleep appears to be a recent development, it’s at least clear to me that we do need all that time.

So, if you do find yourself awake in the middle of the night, hopefully this article will help you remember that you’re not (necessarily) a hopeless insomniac.

Sometimes we may just need an little attitude adjustment before embracing the darkness.

Ryan Hurd is a dream researcher, educator, and a contributing sleep expert to Zeology. He is editor of DreamStudies.org and author of the ebook Sleep Paralysis: A Dreamer’s Guide. He is also the proud papa of a healthy new baby boy.

Tagged as: Anxiety, Bedtime Routine, circadian rhythm, Sleep Stealers, Society & Sleep