The lost art of the midnight wakefulness

Health · Published 18 October 2026 Swipe more like this →

In short: Before the industrial revolution and electric light, humans didn't sleep in one long block. Instead, many practiced segmented sleep: a period of rest, a period of midnight wakefulness known as 'the watch,' and a second sleep. But could this ancient rhythm actually be more natural than our modern routine?

In pre-industrial Western civilization, sleep was often biphasic, or divided into two segments. Historian A. Roger Ekirch has identified over 500 references to this pattern, where individuals would fall into a 'first sleep,' wake around midnight for an hour or more, and then return for a 'second sleep.' This period of wakefulness, called 'the watch,' was a time for prayer, reflection, or even scholarly writing. Some researchers even suggest that maintaining this interrupted pattern might help regulate stress.

The shift to monophasic sleep—a single nightly block—is largely attributed to the advent of electric lighting. While modern productivity enthusiasts experiment with extreme polyphasic schedules, such as the 'Uberman' (30-minute naps every four hours) or the 'Everyman' (a 3-hour core sleep with three 20-minute naps), there is no scientific evidence that these methods are more effective or beneficial. In fact, some extreme versions, like Buckminster Fuller’s 1943 regimen of 30-minute naps every six hours, were abandoned due to social incompatibility.

The biological basis for segmented sleep remains a subject of scientific debate. A 1992 study by Thomas Wehr demonstrated that when humans are exposed to long periods of darkness, they naturally adopt a biphasic pattern, sleeping in two four-hour blocks separated by a period of wakefulness. While some studies of non-industrial equatorial societies show monophsinc nighttime sleep, others suggest that shorter, polyphasic sleep may be the ancestral state for many mammals, making our modern single-block habit a relatively recent evolutionary departure.

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