Sleep timing and duration in indigenous villages with and without electric lighting on Tanna Island, Vanuatu.

TitleSleep timing and duration in indigenous villages with and without electric lighting on Tanna Island, Vanuatu.
Publication TypeJournal Article
Year of Publication2019
AuthorsSmit AN, Broesch T, Siegel JM, Mistlberger RE
JournalScience Reports
Volume9
Issue1
Pagination17278
Date Published2019 11 21
ISSN2045-2322
Abstract

It has been hypothesized that sleep in the industrialized world is in chronic deficit, due in part to evening light exposure, which delays sleep onset and truncates sleep depending on morning work or school schedules. If so, societies without electricity may sleep longer. However, recent studies of hunter-gatherers and pastoralists living traditional lifestyles without electricity report short sleep compared to industrialized population norms. To further explore the impact of lifestyles and electrification on sleep, we measured sleep by actigraphy in indigenous Melanesians on Tanna Island, Vanuatu, who live traditional subsistence horticultural lifestyles, in villages either with or without access to electricity. Sleep duration was long and efficiency low in both groups, compared to averages from actigraphy studies of industrialized populations. In villages with electricity, light exposure after sunset was increased, sleep onset was delayed, and nocturnal sleep duration was reduced. These effects were driven primarily by breastfeeding mothers living with electric lighting. Relatively long sleep on Tanna may reflect advantages of an environment in which food access is reliable, climate benign, and predators and significant social conflict absent. Despite exposure to outdoor light throughout the day, an effect of artificial evening light was nonetheless detectable on sleep timing and duration.

DOI10.1038/s41598-019-53635-y
Alternate JournalSci Rep
PubMed ID31754265
PubMed Central IDPMC6872597