Contrary to popular belief, the moon has no impact on a person's sleep, a new study finds.
Popular belief has is that the lunar phases have a significant impact on a person's sleeping habits, with many people reporting poor sleep quality during and around a full moon. Debunking this belief, researchers from the Max Planck Institute of Psychiatry in Munich, found no such association.
For the study, researchers analyzed the sleep data of 1,265 volunteers during 2,097 nights but found no association between the moon and sleep. Instead, the researchers came across many unpublished studies on more than 20,000 sleep nights that further nullified any relation between sleep patterns and lunar phases.
"Investigating this large cohort of test persons and sleep nights, we were unable to replicate previous findings," said study author Martin Dresler in a press statement. "We could not observe a statistical relevant correlation between human sleep and the lunar phases."
The study authors also highlighted many pitfalls of previous studies that claimed the moon may have an effect on a person's sleep. Firstly, none of the studies assessed the effect with objective measures like a sleep EEG.
Two studies conducted between 2013 and 2014 concluded that a full moon may result in shorter sleeping durations. Through both studies drew similar conclusions, they reported contradicting results. While one study said that the period where we usually dream was delayed around new moon, the other reported this delay around full moon. Additionally, one study said lunar phases had a greater impact of a woman's sleeping habits while the other said it affected men more.
Researchers also highlighted the file drawer problem that studies frequently face. This includes many studies that are conducted but never published, due to various reasons, one of which being publication biasness.
"To overcome the obvious limitations of retrospective data analysis, carefully controlled studies specifically designed for the test of lunar cycle effects on sleep in large samples are required for a definite answer," Dresler said.
Findings of the new study were published online in the journal Current Biology.