Some eye-opening thoughts on sleep

In the U.S., it's perfectly normal to sleep with your dog or cat, but huge cultural battles are being fought over whether it's odd, or even detrimental, to sleep with your baby. In much of the developing world, people think just the opposite, says anthropologist Carol Worthman.

By Carol Clark

Emory anthropologist Carol Worthman first began thinking about the cultures of sleep while traveling across Kenya in 1979 as a postdoctoral fellow. She was headed to the coast in an old, classic train with wooden slats that rolled down over the windows. The cheap ticket section was so packed for the overnight journey that mothers and children shared bunks in the women’s section.

“Children were crying. It was really noisy and I couldn’t get comfortable. I didn’t sleep much at all,” Worthman says.

The locals, however, took it in stride. “In the morning, everyone around me got up looking bright and beaming,” Worthman says. “I thought, ‘They don’t sleep like Westerners do.’”

Nearly two decades later, Worthman was asked by a pediatrician to sum up what anthropologists know about sleep. She thought about it and had to respond, “Not much.” While most waking moments of human activity were well-documented, their sleeping ones were largely ignored by anthropologists.

“When people go to sleep is when we can finally write up our notes,” Worthman jokes.

But the realization that her field had overlooked one-third of human life spurred her to work on the first analytic framework for comparative studies of human sleep behavior in 1998.

She pored over the literature, and interviewed field researchers about their observations of the ecology of sleep from across continents, cultures and climates in the developing world. From foragers to farmers, islanders to mountain dwellers, patterns of sleep behavior began to emerge.

“I was startled,” Worthman says. “You learn just how weird our sleeping habits are in the United States.”

For instance, many Americans consider it odd, and perhaps detrimental, to sleep with a newborn baby. And yet it’s perfectly normal to sleep with a dog or cat.

“In much of the developing world, people think just the opposite,” Worthman says. “It’s pretty much universal that babies don’t sleep alone. They either lie right next to their mothers, or nearby on a mat, or in a cradle or a sling.”

Putting a baby in a separate room to sleep would be viewed as tantamount to child abuse in many cultures, Worthman says.

For much of human history, humans have slept in family groups, with one ear cocked for danger. They were comforted by the sounds of their livestock shuffling, their babies breathing and the crackle of a smoky fire to ward off bugs and larger predators. “Sleeping like a log” is not so desirable if you could roll into the fire, or miss the sound of an approaching predator.

Worthman’s work has shown that rural, and even some urban, communities of the developing world have markedly different sleeping patterns than the typical American. “You can actually quantitatively show that culture drives human sleep behavior,” she says.

Building on her decades of research, Worthman is about to launch the first quantitative study of a pre-electric sleep culture, a major experiment set to begin soon in rural Vietnam. Click here to read more about the study.

It’s only relatively recently that electricity, larger homes, box springs, non-allergenic mattresses and climate-controlled interiors have altered our sleep environments. This rapid shift leads Worthman to wonder if modern sleep practices have set us up for chronic problems such as insomnia, sleep apnea and parental anxiety over a newborn’s sleep patterns.
Photo by Klaus Roesch

For instance, in many cultures, people tend to take more naps and have less rigid expectations for sleeping straight through the night. Some evidence indicates that in pre-gaslight Europe, it was not uncommon for people to have an early evening sleep, then wake up later in the night for a while, before returning to a deeper sleep state.

Modern-day insomniacs may actually be the more normal ones, Worthman notes. “In our culture, we have this very fixed idea that you should lie down and go out like a light,” she says. “One of the problems with insomnia is that people become very anxious about it. If they relaxed, went with the flow, and perhaps took a nap during the day, maybe it would help.”

All images, iStockphoto.com, unless otherwise noted.

Related:
Shedding light on a pre-electric sleep culture
Grandma was right: Babies wake up taller
The science of sleep