Sleep across Cultures

From an essay by T.M. Luhrman:

The rural Toraja almost never sleep alone. They sleep in wood frame houses with little furniture and flimsy room dividers, and they sleep on the floor together in groups, sharing blankets and huddling close for warmth. And so the Toraja have “punctuated” sleep. They wake often as others turn and get up in the night, or when a child calls out or another adult can’t sleep and starts to chat. . . .

This obsession with eight hours of continuous sleep is largely a creation of the electrified age. Back when night fell for, on average, half of each 24 hours, people slept in phases. In “At Day’s Close,” a remarkable history of night in the early modern West, Roger Ekirch writes that people fell asleep not long after dark for the “first sleep.” Then they awoke, somnolent but not asleep, often around midnight, when for a few hours they talked, read, prayed, had sex, brewed beer or burgled. Then they went back to sleep for a shorter period. Mr. Ekirch concludes, “There is every reason to believe that segmented sleep, such as many wild animals exhibit, had long been the natural pattern of our slumber before the modern age, with a provenance as old as humankind.”

Luhrman is mainly an anthropologist of religion, and she thinks that punctuated sleep encourages people to pay more attention to their dreams. Spiritual or supernatural experiences, she thinks, often happen to people who are half awake in the middle of the night:

Recently, I spent time in similar evangelical churches in Accra, Ghana, and Chennai, India. One of the more startling differences is that Christians in Accra and Chennai say that God talks to them when they sleep, and in their dreams. He wakes them up by calling their names.

Could it be that things like electric lights, work days measured by the clock, and sleep cycles governed by alarm clocks quite profoundly change how we experience the world?