New research published on Wednesday suggests that human sleep patterns are much more dependent on the shifting phases of the moon than previously thought.
A team of researchers from the University of Washington (UW), Yale University and the National University of Quilmes, in Argentina, determined that in the three to five days leading up to a full moon, humans go to bed later in the evening, prompting them to sleep for a shorter period of time.
Officials came to the conclusion by using sleep-monitoring wrist devices on 98 people living in three Toba-Qom indigenous communities in Formosa, Argentina. The three communities varied from one another either by limited or full access to electricity.
The study found that participants' sleep duration changed between 20 and over 90 minutes, and the time that people hit the hay differed between 30 and 80 minutes.
In addition to a lack of sleep preceding a full moon, officials determined that participants also slept much longer on nights before a new moon. Researchers also indicated that the so-called “lunar phase effect” on sleep was more prominent based on one’s access to electricity.
To confirm their findings, researchers compared their results to sleep data collected in a separate study that examined the sleep habits of 464 college students at the University of Washington. Ultimately, scientists determined that results showed strong similarities to their study.
“We see a clear lunar modulation of sleep, with sleep decreasing and a later onset of sleep in the days preceding a full moon,” Horacio de la Iglesia, study author and biology professor at UW, said in a statement. “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.”
Acknowledging that the moon’s effect on human sleep patterns has remained a controversial subject within the scientific community, lead author Leandro Casiraghi in statement in the Wednesday UW release suggested that future studies could offer a deeper examination on other potential options affecting sleep habits, such as one’s circadian clock.
The study, funded by the National Science Foundation and the Leakey Foundation, was published in the journal Science Advances.