Nature's Way

A few weeks ago, I chanced upon this article from the BBC which suggests that for much of human history it was common for people to 'retire to bed' for most of the hours of darkness, but to wake up - and enjoy a reviving spell of activity - for a few hours in the middle. Apparently, this didn't really change until public streetlighting first started to become commonplace in Europe towards the end of the 1600s. Before that, the limitations of lighting technology meant that it wasn't safe or appealing to go out of doors at night, and even options for entertainment at home were fairly few. People used to dine at or shortly after dusk, and go to bed soon afterwards.

However, most people found it hard to sleep for more than 4 or 5 hours at a stretch, particularly when retiring so early; hence, it was supposedly a standard habit to rise for 2 or 3 hours in the middle of the night, and then return to bed to sleep through until dawn. In one of my earliest posts on here, I wondered how on earth Samuel Pepys had found the time for his prolific diarising; I assumed that he'd put in an hour or two before he went to bed each night, but perhaps in fact he was finding his writing hours between midnight and 2am.  References to 'first sleep' and 'second sleep' used to be commonplace, both in medical textbooks and in literature, and persisted through most of the 19th century (this brief anthology of such quotations, inspired by the BBC piece, begins with one from Dickens' Barnaby Rudge). Cervantes made gentle fun of Sancho Panza for his rare ability to make one sleep last the whole night long.

Nowadays, when most of us have longer days, harder nights, and turn in much later, one sleep is all we have time for; but we're usually exhausted enough to sleep for 6 or 7 hours at a stretch, and wake up reasonably well rested the next morning. Scientists speculate, however, that many sleep disorders - and particularly sudden wakefulness in the wee small hours - may trace their origins to this; they suggest that human diurnal rhythms favour the pattern of two shorter sleeping periods separated by an interval of activity, and that the eight-hours-a-night formula is an unexpectedly stressful imposition of modern life - 'unnatural' and potentially harmful.

Neither the BBC item nor anything else I've yet found on this discusses how or when eight-hours-a-night became the standard prescription. Nor is there any consideration of the custom of afternoon sleeping - siesta - in hot climates. Nor indeed of how cycles of perpetual night and perpetual daylight affect the sleeping habits of Lapps and Eskimos.

I did, however, discover a chap who is convinced that standing on one leg "to exhaustion" at least four times a day ensures a sound night's sleep, and a would-be scientific study that purports to confirm the benefits to creativity of REM sleep.

I have slept rather badly through most of the time I have lived in China, or, rather, in Beijing (I have slept very well in most other parts of the country I've visited). I attribute this to the fact that half of the city is a building site, and thus heavy plant is frequently rumbling up and down the street at odd hours of the night.