Does the Full Moon Really Have an Effect on People?

"There must be a full moon tonight." That's a popular phrase uttered in almost every office at some point when the customers are especially rude or strange. Some offices even post lunar calendars or send emails notifying staff of moon phrases as if it was upcoming hurricane activity.

What is the reason for the apprehension of other people when the moon is full? Is this fear mere superstition, or do we actually respond to moon phases?

The lunar effect is the name for the theory that the phases of the moon affect people's behavior. The word lunacy is derived from lunaticus, with "Luna" being the latin word for moon. Moon phases have been blamed for suicide, homicide, assaults, and linked to births and changes in menstrual cycles. One stock trader on the Silicon Investor website (http://siliconinvestor.advfn.com) even admitted to buying and selling stocks according to phases of the moon.

One study that garnered a lot of attention on this subject was Arnold Lieber's book released in 1978, "Lunar Effects: Biological Tides and Human Emotions", in which Lieber linked moon phases to murder rates in Miami-Dade County, Florida. He called the Miami-Dade police and local media, and according to him, "all hell broke loose".

The theory that the state of the moon affects human behavior or events is debunked by researchers like Eric Chudler, a research associate professor in bioengineering at the University of Washington. When ABC News did a report on the effect of the moon ("Bad Moon Rising: The Myth of the Full Moon"), Chulder, who has studied over a hundred papers on the subject told them that the research "does not confirm that there is a change in the amount of violence, reported crimes or aggressive behavior during a full moon." He went on to explain that "correlation does not mean causation", meaning that although a study may show a heightened amount of homicides or suicides during a full moon, there's no way to prove that the lunar phase caused these events. Professor Ivan Kelly, psychologist James Rotton and astronomer Roger Culver examined over one hundred reports of activity that was supposedly linked to lunar phases in 1986. They didn't find anything that supported the lunar effect.

Still, the superstition remains. For every report that links the moon cycles to criminal behavior or important events, there is another that debunks the entire lunar effect theory. The belief is substantiated by folklore, tradition, and communal reinforcement, defined by the Skeptics Dictionary (http://skepdic.com) as "the process by which a claim becomes a strong belief through repeated assertion by members of a community". If a belief is widely repeated, it is taken as fact, even if there is proof that debunks the belief. Another aspect is that while some people do indeed fear a full moon, some people keep an eye on the lunar calendar for the same reason that they read their horoscopes - it's fun. Also, on a smaller scale, it's somewhat comforting to be able to see a full moon on the lunar calendar and blame erratic customer behavior on the moon's phase rather than current politics, the weather, or general bad moods. It's exotic, it's interesting, and it makes us feel more connected to the universe. When it comes to a full moon, superstition seems to win over science.