Sleep cycles in people oscillate during the 29.5-day lunar cycle: In the days leading up to a full moon, people go to sleep later in the evening and sleep for shorter periods of time. The team, led by 91自拍ers at the 91自拍, observed these variations in both the time of sleep onset and the duration of sleep in urban and rural settings 鈥� from Indigenous communities in northern Argentina to college students in Seattle, a city of more than 750,000. They saw the oscillations regardless of an individual鈥檚 access to electricity, though the variations are less pronounced in individuals living in urban environments.
