Spooky Study: Does Crime Really Increase During A Full Moon?

NEW YORK — A full moon on a spooky night is synonymous with werewolves, witches, and Halloween folklore in general. Humans have been captivated by the glow of the moon on a clear night for as long as ghost stories have been told around campfires, but does a full moon really cause people to act strangely?

Dubbed the “lunar effect,” the belief that people are more aggressive and impulsive when the moon is full can be traced back to ancient times. Now, a new study has investigated the supposed relationship between the full moon and crime rates.

Researchers from New York University’s BetaGov team collaborated with the Vallejo, California police department to determine if crime really does increase during a full moon. Unfortunately for all you horror fans out there, they found no significant uptick in reported crimes or arrests during nights when the moon is full.

BetaGov is a specialized branch of NYU’s Marron Institute of Urban Management that works hand in hand with actual stakeholders in the fields they investigate. In this case, the stakeholder was a police official in Vallejo, California.

First, researchers performed a comprehensive analysis of all the research that had previously been published on the lunar effect, discovering that the results were largely mixed. Some studies had found evidence of a lunar increase in crime and overall negative behavior during a full moon, while others had identified no such relationship.

Simultaneously, the collaborating Vallejo police official gathered together all of the local department’s crime data for January 2014 to May 2018. More specifically, the officer determined the phases of the moon during each and every crime event that took place during that time period, and passed his findings along to the team at NYU. The data, however, did not reveal any association between increased crime and the full moon.

Of course, that analysis was only regarding Vallejo, California, and when other police departments heard about the study they wanted to investigate their own local data on full moon crime rates as well. So, BetaGov also conducted similar sets of research with the Barrie, Ontario Police Force in Canada and the Irapuato Citizen Safety Secretariat in Mexico.

Again, though, those investigations also showed no uptick in crime during full moon events were found.

“Although these kinds of analyses are fun, the findings have practical implications for policing such as in developing staffing assignments and distribution of other law-enforcement resources,” says BetaGov director Angela Hawken in a release. “The bottom line is be vigilant in questioning your assumptions and use your data to explore. It might just surprise you.”