"The overwhelming evidence is negative," said Chudler of the University of Washington, a neuroscientist who has looked at 100 peer-reviewed papers on the lunar effect. "Most of them show no correlation but even if there is a correlation, it doesn't mean one causes the other."
That hasn't stopped police from drawing their own conclusions. In the seaside resort of Brighton, England, the police department decided in 2007 to put extra officers out on the streets during full moons after comparing crime data and lunar graphs and finding that violence waxed and waned along with the moon.
"From my experience, over 19 years of being a police officer, undoubtedly on full moons, we do seem to get people with sort of stranger behavior — more fractious, argumentative," Andy Parr, an inspector with Sussex police, told the BBC.
Chudler's sister-in-law, a sheriff in the Seattle area, is a staunch believer in the lunar effect, he said.
"Of course when you talk to the bartender or the police officer or the nurse they'll say there's an effect," he said.