“The full moon causes unusual behavior and increased crime”

The notion that the full moon brings about unusual behavior and a surge in crime has deep historical roots. The very word "lunatic" stems from the Latin "lunaticus," meaning "moon-struck" or "of the moon," reflecting a long-held belief in the moon's influence over the human mind. Ancient philosophers like Aristotle and Pliny the Elder even theorized that the full moon could alter the brain's moisture content, similar to its effect on ocean tides, thereby leading to madness or epileptic episodes. Tales of insanity and even mythical creatures like werewolves tied to the full moon further cemented this idea in folklore through medieval Europe.

Despite these centuries-old beliefs, extensive modern scientific research has consistently found no significant correlation between the lunar cycle and human behavior. Numerous studies, including large-scale meta-analyses that review decades of data on emergency room visits, crime rates, psychiatric admissions, and other indicators of erratic behavior, have debunked the so-called "lunar effect." While a few isolated studies have claimed to find a link, these are often attributed to statistical anomalies or methodological flaws, such as failing to account for other variables like weekends or holidays. The common theory that the moon's gravitational pull affects the water (Review) in our bodies, similar to tides, is scientifically implausible, as the moon's gravitational force is far too weak to have such an impact on individual human physiology.

The persistence of this myth largely stems from a psychological phenomenon known as confirmation bias. People tend to notice and vividly remember instances of unusual behavior or events that happen to coincide with a full moon, while inadvertently overlooking the countless full moons that pass without any remarkable incidents. This selective memory creates a compelling, yet false, impression of a connection where none truly exists. Additionally, before the advent of widespread artificial lighting, the bright light of a full moon could have genuinely disrupted sleep patterns, potentially exacerbating mental conditions in predisposed individuals, which may have contributed to the myth's origins as a "cultural fossil."