Shedding light on a pre-electric sleep culture

A sleeping Buddha in Southeast Asia. "The window of opportunity to understand sleep without electricity is closing, because the traditional cultures of sleep are vanishing," says anthropologist Carol Worthman.

By Carol Clark

About 20 percent of the world population lives without electricity. You may wonder how these people make it through their waking hours, but Carol Worthman wants to know how they sleep.

Worthman, an anthropologist at Emory University, is leading the first quantitative study of sleeping habits in a pre-electric environment. The sleep study is just one part of a larger, five-year project to begin soon in rural Vietnam, involving 14 villages that have not been electrified or exposed to television. Half of the villages will eventually be introduced to generator-powered televisions for the experiment, while the other half will not.

The National Institute of Health and the Vietnamese government are supporting the project, headed by Penn State, which aims to answer questions about how watching television affects human health and behavior.

Worthman, a leading expert on the ecology of sleep, is most excited about garnering the baseline data for pre-electric sleep. “The window of opportunity to understand sleep without electricity is closing, because the traditional cultures of sleep are vanishing,” she says. One of the development goals of WHO, she notes, is to see every populated part of the world electrified by 2020.

“We will be filling a gap in scientific knowledge by getting the first empirical data for how people sleep with no electricity, just the sun, when their whole world revolves around subsistence and nature,” Worthman says. “Many people have this idea that in the good old days we got more sleep, but did we? Are we romanticizing our history?”

A Vietnamese woman relaxes with her baby. One development goal of WHO is to see every part of the world electrified by 2020.

The 14 villages involved in the study are in a remote, mountainous location of Vietnam, near the Laotian border. Most of the people in the area belong to the Tai ethnic group and are subsistence farmers. Whole families generally sleep in one or two rooms, due to the small size of the homes.

Participants in the experiment will continuously wear a sleep actigraph, a wristwatch-like device that records movement. An actigraph is sensitive enough to detect whether its wearer is sleeping or just resting, has entered a deep sleep state, known as REM, and how often the wearer stirs or wakes up from a deep sleep.

“The data will suggest the architecture of their sleep,” Worthman says. “We will get a sense of how much sleep they are getting, whether it is interrupted frequently, and whether their sleep is mostly consolidated, or more scattered across 24 hours through naps.”

The experiment is expected to begin this Spring. After the baseline data are collected, seven of the villages will serve as controls for the experiment, while televisions powered by generators will be introduced to the other half. Every 20th household will get a communal TV set, with three channels of programming that run from 4 pm to 10 pm. At several points over the course of five years after the introduction of TV, the sleep patterns of the subjects will again be monitored to see if they have changed.

A satellite dish pokes up between two thatched huts in an isolated area of Vietnam. Anthropologists want to know how TV changes people's sleep patterns, and their outlook on life.

“This experiment is not going to answer all the questions about human sleep, but it could provide us with some fresh ideas and questions,” Worthman says.

Are some of the sleep disorders common to modernized society tied to electricity and TV viewing? One theory holds that people who watch TV lose major chunks of time, forcing them to stay up later to complete other tasks like cleaning or doing homework. Some people watch TV to relax in the evening, but how does all that light beamed into their eyes just before bed affect their ability to get to sleep? Does the content of the programs affect sleep?

Adolescents typically experience a change in their biological clocks, causing them to want to stay up later and get up later. “TV and other forms of media can feed that propensity,” Worthman says, “but then they get slammed the next day because they have to get up for school.”

The overarching study will look at larger effects of TV viewing on health and well-being, beyond sleep. Worthman will also collect both baseline and follow-up data for this segment of the study, with a focus on adolescents.

Her team will look at how the activities, social lives and relationships of teenagers, along with their values, goals and attitudes, change after the introduction of TV.

“One thing we’re interested in is how learning about life outside of their village through TV may affect them,” Worthman says. “Will they will find TV programming inspirational or frustrating? What’s the role of a globalized world in fostering anxiety? If you are plugged into media, are you less, or more, depressed and anxious?”

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