A once-monthly phase of the Earth’s moon, that has been anecdotally linked to all ilk of human behaviour, an association which remains unproven. Full moons have been linked to crime, suicide, mental illness, disasters, accidents, birth rates, fertility, werewolf “outings,” etc.; there are no valid studies linking human behaviour to the moon–however…
Some people buy and sell stocks according to phases of the moon, a method probably as successful as many others. Kelly et al examined over 100 studies on lunar effects and concluded that the studies have failed to show a reliable and significant correlation–i.e., one not likely due to chance between the full moon, or any other phase of the moon, and each of the following: aggression by professional hockey players, agitated behaviour by nursing home residents, alcoholism, assassinations, assaults, behavioural outbursts of psychologically challenged rural adults, births of babies, casino pay-out rates, crisis calls to police or fire stations, domestic violence, emergency room admissions, epilepsy, gunshot wounds, homicides, kidnappings, lycanthropy, major disasters, psychiatric admissions–one study found admissions were lowest during a full moon!!!, sleep walking, stabbings, suicide, homicide rate, traffic accidents, vampirism, violence in prisons.
Given the lack of correlation between the full moon and any event, why does the myth persist? Kelly et al suspect 4 factors:
• Media effects
• Folklore and tradition
• Cognitive biases
A 5th factor should be considered: communal reinforcement
IW Kelly, J Rotton, R Culver, in The Moon was Full and Nothing Happened: A Review of Studies on the Moon and Human Behaviour and Human Belief, The Outer Edge (Amherst, N.Y., 1996)