A brief history of time (spent in bed)

Catching Zs is a fact of life, but it didn’t always mean dimming the lights, popping some melatonin, and turning the white noise machine on. In fact, even sleeping through the night is a relatively modern development. Sleep as we know it has transformed from era to era and culture to culture — what works for us now may not have been practical or effective for our ancestors, and vice versa…

…Maybe. It may just be that sociological and technological advancements have forced us to restructure how we spend our time in bed.

People have been philosophizing about the reason behind and benefit of a good night’s sleep since at least 450 BC. The first recorded instance came from Alcmaeon, an ancient Greek physician, who believed that our need for sleep was due to a poor circulation to the brain. Over 600 years later, another Greek philosopher, but this time one who was also a physician, (correctly) suggested that it was the brain that was responsible for consciousness (or lack thereof).

Why sleep once when you can sleep twice? In 2001, historian Roger Ekrich published evidence that our ancestors slept in phases instead of the long uninterrupted stretch we’ve come to know (and love). Biphasic sleeping was noted in Homer’s 8th century BC epic Odyssey, where the poet referred to “ the first sleep.” The period between the first and second stages of sleep (which took place from 9pm-11pm and then 1am-6am) were used for socializing, taking part in hobbies, or just lounging around. References to biphasic sleeping were found in literature from the 15th, 16th, and 17th centuries, suggesting that this was the norm for millenia across Europe, Africa, South East Asia, and Australia.

Thomas Edison, inventor, businessman, enemy of sleep. For whatever reason, Edison thought sleep was bad for us, and a mark of laziness. “The person who sleeps 8 or 10 hours a night is never fully asleep, and never fully awake,” he said. So he had no problem whatsoever watching our natural rhythm of sleep change drastically, and perhaps permanently.

In 1879, artificial light made its way into people’s homes, and ushered in the extinction of biphasic sleep. The widespread use of the lightbulb allowed people to stay up, work, or socialize during hours of darkness that otherwise would have immobilized those activities. To test the effect of artificial light on our sleep cycles, psychiatrist and scientist Thomas Wehr conducted a sleep experiment in 1992, wherein volunteers were placed in an environment that was dark for 14 hours of the day. Wehr found that by the fourth week, the subjects slept an average of eight hours a night, but in two separate cycles, concluding that we have an inherent inclination for biphasic sleep patterns, and that artificial light interrupted it.

More light, more work. Thanks, Edison. But the industrialized world thrived on this invention, which allowed people to work long after the sun had set, and ultimately changed our attitudes toward sleep. As the workday ate into our sleep schedule, even six hours a day became unattainable for the working class, who — without labor laws in place to account for this advancement — experienced a workday that stretched to no official end. This fueled labor movements in the early 19th century, most notably by the Welsh, who called for eight hours of labor, eight hours of recreation, and eight hours of rest. And thus was the introduction of the eight-hour sleep cycle rule of thumb.

Is it enough as it is? The 20th century saw a focus on the improvement of sleep quality, which had been steadily declining on a worldwide scale. Ekrich is convinced that the amount of people experiencing sleep disorders aren’t experiencing a disorder at all, but “remnant[s] or echoe[s] of [our] earlier pattern of sleep.” The first sleeping pill, Barbital, was introduced in 1903. By 1930, just 27 years after its introduction, experts estimated that the US alone had collectively ingested over 1 bn of them. Today, the pharmaceutical sleep industry is estimated to be worth USD 32 bn.

I’ll sleep when I’m dead. Author of Wild Nights: How Taming Sleep Created Our RestlessWorld, blames capitalist work ethics for the idea that sleep is wasted time indulged only by the laziest of us — an idea we have yet to shake off, judging by the number of executives that swear by a five-hour night. It’s no coincidence that “when it became more efficient to routinize work and have large numbers of people showing up on factory floors and doing as much work [as] possible” is when the grind became the marker of success, wrote Reiss.