Sleep - Anthropology of Sleep

Anthropology of Sleep

Research suggests that sleep patterns vary significantly across cultures. The most striking differences are between societies that have plentiful sources of artificial light and ones that do not. The primary difference appears to be that pre-light cultures have more broken-up sleep patterns. For example, people might go to sleep far sooner after the sun sets, but then wake up several times throughout the night, punctuating their sleep with periods of wakefulness, perhaps lasting several hours. The boundaries between sleeping and waking are blurred in these societies. Some observers believe that nighttime sleep in these societies is most often split into two main periods, the first characterized primarily by deep sleep and the second by REM sleep.

Some societies display a fragmented sleep pattern in which people sleep at all times of the day and night for shorter periods. In many nomadic or hunter-gatherer societies, people will sleep on and off throughout the day or night depending on what is happening. Plentiful artificial light has been available in the industrialized West since at least the mid-19th century, and sleep patterns have changed significantly everywhere that lighting has been introduced. In general, people sleep in a more concentrated burst through the night, going to sleep much later, although this is not always true. Historian Roger Ekrich thinks that the traditional pattern of "segmented sleep" as it is called began to disappear among the urban upper class in Europe in the late 17th century and the change spread over the next 200 years; by the 1920s "the idea of a first and second sleep had receded entirely from our social consciousness." Ekrich attributes the change to increases in "street lighting, domestic lighting and a surge in coffee houses," which slowly made nighttime a legitimate time for activity, decreasing the time available for rest.

In some societies, people generally sleep with at least one other person (sometimes many) or with animals. In other cultures, people rarely sleep with anyone but a most intimate relation, such as a spouse. In almost all societies, sleeping partners are strongly regulated by social standards. For example, people might only sleep with their immediate family, extended family, spouses, their children, children of a certain age, children of specific gender, peers of a certain gender, friends, peers of equal social rank, or with no one at all. Sleep may be an actively social time, depending on the sleep groupings, with no constraints on noise or activity.

People sleep in a variety of locations. Some sleep directly on the ground; others on a skin or blanket; others sleep on platforms or beds. Some sleep with blankets, some with pillows, some with simple headrests, some with no head support. These choices are shaped by a variety of factors, such as climate, protection from predators, housing type, technology, personal preference, and the incidence of pests.