Pregnant women gather in a park in Oeiras, Portugal for an event to celebrate birth in July 2007. Some people believe that a full moon causes an increase in birthrates.

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Putting Full Moon Theories to the Test

Although fear surrounding epileptic seizures had been around for centuries, the connection to the full moon's supposed strength was popularized in 1978 when a psychiatrist named Arnold Lieber published "Lunar Effects: Biological Tides and Human Emotions." In a nutshell, the book emphasized the moon's ability to utilize gravitational pull in a way that affects humans.

Some people bought into this idea because the moon's gravitational pull does impact the Earth's ocean tides. Lieber further detailed his "biological tides" theory, which noted that, since the human body is 80 percent water, it stands to reason that the moon can control it in the same way it controls the ocean's water. Unfortunately for Lieber, the majority of scientists now concur that the moon is far too distant to make an impact on teeny-tiny humans, even if we are made up mostly of water. Nevertheless, Lieber and others plugged away. He even published an updated version of his book as recently as 1996.

A few studies have claimed to show a connection between the full moon and various consequences, but they're often discredited due to problems with the scientific methodology used. In 1996, three scientists -- Ivan Kelly, James Rotton and Roger Culver -- released findings from their own review of more than 100 studies dealing with lunar effects. They found that the studies failed to present a significant correlation between the full moon and any of the behaviors it supposedly causes.

A team of University of South Florida researchers completed what they believe to be a definitive answer to the question of whether or not the full moon causes epileptic seizures. The team reviewed 770 seizure occurrences over a three-year period that took place in the epilepsy monitoring unit at Tampa General Hospital. The goal, of course, was to determine whether or not epileptic seizures occurred more often during full moons.

The study, which was published in the scholarly journal "Epilepsy and Behavior," revealed that the full moon period actually had the fewest epileptic seizures with only 94. The moon's last quarter boasted the most, with 152. These results led the scientists to conclude that there is no significant correlation between the full moon and increased incidence of epileptic seizures.

As far as the many full moon theories go, research has yet to validate any of them. Despite this fact, the theories persist among the masses of pregnant women who have gone past their due dates, epileptics who yearn for some way to predict their seizures. Kelly, Rotton and Culver believe there are several reasons that these beliefs continue to pervade modern society, despite a lack of solid evidence:

  • Media influence (presentation of the full moon and related myths in movies, television, books, etc.)
  • Folklore and tradition
  • Common misconceptions
  • Cognitive biases (the misconception has been repeated so many times by influential people that others take it as fact without questioning it)

It is doubtful that 100 percent of the population will ever accept the moon's limitations as fact. However, the vast majority of the scientific community does. Can believing in these myths hurt anyone? Probably not. In fact, it can be kind of fun placing pregnancy due date bets based on the lunar calendar. Just don't gamble your life savings away on it.