To sleep, perchance to … wake up, potter about a bit, and then go back to sleep?
“Until the close of the early modern era, Western Europeans on most evenings experienced two major intervals of sleep bridged by up to an hour or more [sic] of quiet wakefulness.”
The phases of sleep – the first and second – lasted roughly an equal length of time. The intervening period of wakefulness was called the watch or watching. During this hour people got up to all sorts of things – prayer, some study, a tipple or two, a bit of slap-and-tickle, or even a spot of burglary (p.305 ff.).
Ekirch cites a Tudor example: the English physician, Andrew Boorde (c.1490 – 1549), mentions the first sleep in a chapter dedicated to sleeping in his, A compendyous regyment or a dyetary of helth (1542/47, p.247):
In the nyght, let the wyndowes of youre howse, specially of your chambre, be closed; whan you be in your bed, lye a lytel whyle on your left syde, & slepe on your ryght syde. And whan you do wake of your fyrste slepe, make water yf you fele your bladder charged, and than slepe on the lefte syde; and loke, as ofte as you do wake, so ofte tourne yourselfe in the bed from the one syde to the other.
Not much to go on, but interesting. Boorde has a variety of observations on sleeping habits, does-and-don’ts, etc.: he refers to Luke 22:39-46, when Jesus urged his sleepy disciples to keep watch in the Garden of Gethsemane, and to the practice of the night watch in military camps and ships at sea. Are these examples of a natural period of wakefulness? Boorde doesn’t make it clear.
Back to the modern study: another point addressed by Ekirch is whether this pattern arises from the Christian discipline of night vigils. He notes the practice in monasteries from the 6th century onward, and the advice to this end given in another Tudor-era work, the 1588 commentary on The Dark Night of the Soul by St John of the Cross.
Ekirch finds that the same pattern existed among the ancients, and concludes that the Christian practice is not the source of segmented sleep. Rather, he reckons the pattern is primeval, similar to that followed by other mammals, and has been disturbed by our use of artificial light. The working assumption seems to be that this is how we evolved, and that current patterns may be detrimental to our health.
Most of Ekirch’s evidence is in glancing references (like Boorde’s), drawn from all points of the compass and across time. It’s understandable our ancestors failed to remark much on this phenomenon or to record it – after all, why should a fish observe the water?
So I’m not entirely convinced by the final thesis, but my judgment may be coloured by the torture I endure trying to get back to sleep in the middle of the night.
NB – the Wikipedia article on segmented sleep does have references to scientific research.