Kat Duff is the award-winning author of The Alchemy of Illness and The Secret Life of Sleep, which both set out to illuminate experiences often dismissed as private and off limits. In answer to my questions, she shared her insights on sleep in ancient cultures, changing attitudes toward sleep over time, and how (and especially how not) to wake someone up.
The title of your book is The Secret Life of Sleep -- why do you believe our sleep lives have become "secret"? What inspired you to write the book?
I think of sleep as having a secret life in part because we are largely unaware of what occurs during that third of our lives, but also because the western scientific tradition ignored it for so long as irrelevant to our waking lives. But I've always loved to sleep, and even as a child noticed that it often changed me in unexpected ways. I would wake remembering things I'd forgotten the night before. The regrets, worries and fears that plagued me the night before seemed smaller in the morning. Dreams occasionally shifted the ways I saw people or thought about things. These experiences left me with a lifelong curiosity about what happens behind our closed eyes.
What are some examples that you think are especially profound in the way ancient societies treated sleep and its place in their culture?
While it's next to impossible to know for sure how ancient peoples regarded their sleep lives, the written records that remain, especially the medical and religious texts from India, China, Egypt, Greece and elsewhere, make it clear that sleep was regarded as an important part of life, one that sometimes offered experiences and teachings that could improve our waking lives and prepare us for dying. Dreams were studied for clues to medical problems and guidance for making big decisions. "One should consult one's bed," wrote the 5th century bishop Synesius of Cyrene, "as one would consult the oracle at Delphi."
In some of the older Hindu, Buddhist, and Egyptian texts, sleep was viewed as a spiritual practice that prepares us for the shifts in consciousness required by death, especially the withdrawal from the outer world of objects and the inner world of thoughts and images. I was astonished to learn that deep, dreamless sleep was considered to be the highest state of consciousness in many of the oldest Buddhist, Hindu, Taoist and Sufi teachings. Growing up in the West, I had learned to assume that conscious awareness was not only the highest form of awareness, but the only one worth considering!
I love what you wrote about the Ashanti and the Maori. What are some other examples of sleep traditions and rituals from around the world?
One of my favorites is the simple admonition not to wake someone up abruptly. It's considered to be bad manners in many cultures for a variety of reasons. Some traditional peoples believe that our souls leave our bodies and travel about at night while we sleep. Waking someone up with a sharp cry (or alarm clock, for that matter) may not give that soul enough time to return to its body. As a result, the person wakes confused and disoriented, even angry. Contemporary scientists explain that an abrupt waking from deep sleep causes "sleep inertia," a drunken-like confusion and irritability. Whatever the explanation, many cultures encourage slow waking practices, especially for guests. Let them sleep until they wake on their own, or encourage them towards waking with a soft song, or letting in a little more light.
Another common tradition involves sleeping with others, be they children, partners, guests, other members of one's own sex, or animals. While the practice may have evolved for practical purposes of warmth, safety or limited space, I find it interesting that as people become wealthy and safe enough to sleep in their own rooms, many choose the company of pets. Many of the traditional Indian and Hispanic people I know, most of whom often sleep with at least one other family member, can't understand why white people invite their pets into their houses and beds. There seems to be a human need, whether biologically or culturally induced, to have the creature comfort of another being in bed with us -- even if it's replaced by a body pillow!
How would you describe the shift in our collective attitude toward sleep as a society, from ancient times to modern day?
The division I would make would not between ancient and modern cultures so much as pre- and post-industrial ones, or between those that have become dominated by globalized western lifeways and those that remain true to their local, environmentally induced lifeways. Sometimes I think it's primarily an urban/rural divide. It appears that the more people live by the dictates of clocks and work schedules in artificially lit environments, as required in most urban environments, the more difficulty they have with sleep, and the more they seek to control it, rather than abide with it. Those who live rurally tend to be more influenced by seasonal and daily cycles of light and darkness, warmer and colder temperatures, that allow for deeper, more restful sleep. Dreams are easier to remember in these contexts, and sleep itself assumes more value.
I saw how the hunter-gatherer study was used in media around the world as a way to challenge the finding that, with the exception of "short sleepers," the majority of people need 7-8 hours of sleep. I would love your thoughts on the study and whether there are other hunter-gatherer studies that reach different conclusions, as it seemed the study was used to support a sleep backlash.
While I was thrilled to see a study of sleep patterns among rural, non-industrialized peoples, rather than the usual college students who volunteer for research studies at universities, I have been amazed by the amount of attention Siegel's study has received, and dismayed by the unwarranted conclusions many reporters have drawn from it.
Let's be clear: the study demonstrates that people in three equatorial non-industrial societies on two continents have "sleep periods" averaging 6.9-8.5 hours, very close to what is currently recommended, and 5.7-7.1 of those hours constituted sound sleep. That's all. It does not say anything about sleep needs of people living in industrialized societies, despite misleading headlines, such as one from The New York Times which read: "Do We Really Need to Sleep 7 Hours a Night?" and the one from the Washington Post, which read: "Sleep Study on Modern-Day Hunter-Gatherers Dispels Notion That We're Wired to Need 8 Hours a Day."
I believe the misunderstanding stems from the fact that Siegel and his colleagues concluded that what they found "expressed core human sleep patterns," or "natural sleep," as they called in their title. There's no such thing as natural sleep apart from the environmental conditions in which it occurs. Sleep patterns that work for peoples in equatorial regions will be different from those in the higher latitudes or altitudes with greater variations in temperature and light, or those exposed to natural predators, food scarcity, warfare, etc.
Horacio de la Iglesia, from the University of Washington, studied sleep patterns of two groups of hunter-gatherers in Argentina, and discovered that those exposed to electric lights got an hour less sleep than those who relied upon natural lighting. Anthropologist Carol Worthman, who has studied sleep cross-culturally for decades, is currently conducting a five year study of fourteen villages in rural Vietnam, half of whom will be introduced to generator-powered television during the course of the study. Another factor under consideration in research comparing sleep habits of urban and rural communities in Brazil is the extent to which sleep is timed by the day/night cycle. There is much more to learn the conditions that favor good, restorative sleep.
In the meantime, we would do well to remember that sufficient sleep is not a matter of hours, but of how we feel and perform the next day. If you wake tired and struggle to stay alert the rest of the day without caffeinated drinks, then you are probably not getting enough. The amount of sleep we get may not be as important as the timing of it, and the quality of what we get. Here I would agree with one of Jerome Siegel's conclusions: "Maybe people should be a little more relaxed about sleeping."