OK, you probably won't become a werewolf, but there is evidence that the full moon really does take a toll on people—even if they don't know it's out there. Scientists reviewed data in which subjects slept in a darkened room where they couldn't see the moon. During round moons, the 33 volunteers, who didn't know the study's goal, took an extra five minutes to fall asleep and slept a total of 20 minutes less than they did during the new moon phase. They ranged in age from 20 to 31 and 57 to 74, the Los Angeles Times notes.
Subjects had lower levels of melatonin during full moons, the BBC notes; melatonin helps regulate the body clock and is produced more in the dark than in the light. Researchers, however, say the brightness of the moon may have had nothing to do with subjects' sleep. "The lunar cycle seems to influence human sleep, even when one does not 'see' the moon and is not aware of the actual moon phase," says a researcher. Adds an expert: "There is a such a strong cultural story around the full moon that it would not be surprising if it has an effect. It's one of these folk things that you would suspect has a germ of truth." (More cool moon news: A new moon was discovered in our solar system ... thanks to one man's hunch.)