Moonstruck Sleep

A study shows that human sleep is synchronized with lunar phases regardless of ethnic and sociocultural background, and of the level of urbanization. The study uses wrist actimetry to show a clear synchronization of nocturnal sleep timing with the lunar cycle in participants living in environments that range from a rural setting with and without access to electricity in indigenous Toba/Qom communities in Argentina to a highly urbanized postindustrial setting in the United States. The results show that sleep starts later and is shorter on the nights before the full moon when moonlight is available during the hours following dusk. The findings are in line with some previous studies and suggest that moonlight likely stimulated nocturnal activity and inhibited sleep in preindustrial communities and that access to much higher intensities of artificial light may emulate the ancestral effect of early-night moonlight, although that moon gravity could also have a time-of-day specific effect on sleep. Source: https://advances.sciencemag.org/