A full moon hangs over Seattle’s Lake Union on April 7, 2020. (GeekWire Photo / Kevin Lisota)
A newly published study adds to the long-debated evidence that humans are hard-wired to sleep less when the moon is full or the lights are on, probably due to the ancestral quirks of circadian rhythm.
The pattern has been documented in a variety of indigenous communities in Argentina and at the University of Washington in Seattle, where bright lights and cloudy weather tend to dull even the full moon’s glare.
“We see a clear lunar modulation of sleep, with sleep decreasing and a later onset of sleep in the days preceding a full moon,” senior study author Horacio de la Iglesia, a UW biology professor, said in a news release. “And although the effect is more robust in communities without access to electricity, the effect is present in communities with electricity, including undergraduates at the University of Washington.”