guest post by A. Roger Ekirch
I at first dreaded the prospect of writing about sleep from an historical perspective. Sleep, to me, was not only a universal necessity but also a biological constant that did not deviate over time or space. But having embarked upon writing a book about nighttime in the early modern world, there was no ignoring it, hard as it might prove to find enough material of sufficient interest to sustain an entire chapter. To my surprise, I shortly discovered that preindustrial households on both sides of the North Atlantic attached enormous importance to their slumber, going to great lengths in an attempt to ensure not only its quality but also their personal safety while abed from perils real and imagined. More, I began discovering references in legal depositions, then housed at the Public Record Office on Chancery Lane, to a “first sleep” followed by a second sleep after an interval of wakefulness during which persons left their beds and, less often, their dwellings. At that point, I knew that I was on to something very strange, which subsequent explorations of plays, poems, novels, and other texts confirmed.
Very helpful as well was my discovery in December 1996, late one night surfing the internet, of a New York Times article describing a clinical experiment conducted by a team led by Dr. Thomas Wehr, a psychiatrist, at the National Institute of Mental Health in Bethesda, Maryland, a Washington, D.C. suburb. Their goal was to recreate, if possible, “prehistoric sleep” by depriving more than a dozen male subjects of artificial light at night. Remarkably, after a period of three weeks, their sleep became segmented along lines similar to what I had discovered in historical sources. As soon as he returned from giving a talk in Italy, I contacted Tom Wehr, who I recall was every bit as excited as was I upon discovering that our respective investigations dovetailed so closely. Immediately, I sent him photocopies of my evidence to date, and he mailed me an article that he had written about the NIMH experiment for a scientific journal. Even though I had originally resolved not to publish any part of my research as an article prior to the book’s publication – At Day’s Close: Night in Times Past (W.W. Norton, 2005) – I made an exception by writing “Sleep We Have Lost: Preindustrial Slumber in the British Isles,” for the April 2001 issue of the American Historical Review.
Since then, I have continued to accumulate evidence relating to segmented sleep, not just in English sources but in a number of European texts. Databases devoted to literature, newspapers, periodicals and the like have been immensely valuable. Although I contemplated a brief article, perhaps for a scientific journal, suggesting the presence of this pattern of slumber in non-Western societies – according to early travel accounts and anthropological literature – I decided instead to focus first upon the dynamics and origins of its transformation in Western societies. Contrary to my original speculation that the transition to seamless sleep was well underway by the 1700s, further research strongly indicated that the pivotal period was the nineteenth century – in short, that our present form of sleep is no older than one and a half centuries. More, I discovered that cultural considerations, in particular changing attitudes toward sleep during the Industrial Revolution, played a role in addition to the increased prevalence of artificial illumination and its impact on human physiology. Finally, while scientists and sleep physicians, in recent years, have begun to speculate with increasing confidence about possible links between segmented sleep and “middle-of-the-night” insomnia,” the most common variety of insomnia in the United States, I wanted to probe this possibility historically, all the while reminding myself that rather than an MD I am a PhD who, in truth, struggled to earn a respectable grade in high school chemistry.