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.”
The research was published today in the open-access journal Science Advances. It’s not the first study to report a correlation between lunar phases and sleep cycles. But it does make use of cutting-edge technology, in the form of wrist monitors, to track the sleep patterns of hundreds of experimental subjects reliably under natural conditions.