Full Moon Myths and Madness

For some, it inspires romance. For others, it elicits madness.

But since time immemorial, people around the world have been bewitched by the full moon, convinced it influences the human psyche and the rhythms of nature.

If you looked outside last night, you might have noticed this month's full moon. And if you caught yourself blaming bizarre behavior or strange events on the cosmic phenomenon, you likely weren't the only one.

Nurses have reported full moons leading to more chaos and more incoming patients. Police have linked full moons to aggressive behavior.

Studies have debunked the connection, though some experts say the increased light could contribute to a rise in mischief-making.

But then why do moon superstitions persist?

"It's a natural phenomenon that is regular and very striking," said Erika Brady, a professor in the department of folk studies and anthropology at Western Kentucky University. "A really good full moon, you can practically read a newspaper by. It's something that really gets your attention."

Phases of the Moon Inspire Intrigue

But since the full moon usually only takes place 12 times a year, give or take, it highlights the phases of the moon, which have intrigued people for centuries.

"The moon is regular in its cycle, but it's not so absolutely regular that it didn't take time for people to figure it out," said Brady, "It seems to link psychologically with the nine months of the human gestation period and the woman's menstrual cycle, and that linkage has always fascinated people."

Even etymology gives us insight into our perception of the moon -- the words lunacy, lunatic and loony all have their origins in the word "lunar." The belief that werewolves morph into their canine incarnations when the moon is full reveals the idea that it is a time of transformation and magic.

Brady said that people in English and Celtic-speaking countries used to believe that you weren't supposed to sleep with the light of the full moon on your face. They thought that the light would pull on your flesh and muscles and disfigure your face.

Moon Affects Ocean Tides, Can it Affect Humans?

Others thought it was bad luck to look at the full moon through the branches of a tree, she said.

Brady also said that some American Indian tribes considered the full moon to be the best time to detox and take part in "sweat lodge" rituals.

Their thinking was that "at that point, the moon's pull is going to pull more out of you," Brady said.

To be fair, there is a hint of logic to the myths linking the moon and human behavior. Earth, much like the human body, is composed mostly of water. If the moon's gravitational pull can affect ocean tides, so the reasoning goes, couldn't it also affect a person's body?

But the science doesn't bear this out.

"Published [research] does not confirm that there is a change in the amount of violence, reported crimes or aggressive behavior during a full moon," Eric Chudler told ABC News. Chudler, a research associate professor in bioengineering at the University of Washington in Seattle, has studied more than 100 research papers on the purported effects of the full moon on human affairs.

Nurses, Police Officers Link Full Moon to Chaos

Still, people persist in believing otherwise. Studies have found that police officers and hospital workers are among the strongest believers in the notion that more crime and trauma occur on nights when the moon is full.

Dr. David Mandell of the Children's Hospital in Pittsburgh and some colleagues studied existing data on health-care myths and did a 2005 study of area nurses. He said he found that 69 percent of surgical nurses in his study believed that a full moon led to more chaos and incoming patients that night.

"It is unbelievable how many nurses in southwest Pennsylvania believed in the superstitions," he told ABC News. But he said that it's simply part of the culture of medicine.

"In any high-stress, fast-paced field like medicine, superstitions run rampant when you feel a loss of control. This is especially true of emergency environments [because] you never know what will walk in. You need some way to explain the unpredictability of your environment," he said. "It passes on from senior to junior people in hospitals -- like old times telling it to new residents coming in."

Moon Myths Cluster Around the Unpredictable

Western Kentucky's Brady said that phenomenon isn't confined to just hospitals.

"You'll find that these beliefs that cluster around the moon, they are also relevant to parts of human behavior that are unpredictable," she said. "It's a way of imposing a categorical order on something that otherwise feels frighteningly out of control."

Some people consult the lunar calendar when deciding when to have surgery, she said. Each part of the zodiac corresponds with a part of the body (for example, legs and ankles are linked to Aquarius, sexual organs to Scorpio). And, as the moon moves through the different signs, the superstitious caution against medical intervention on that body part or region.

For farmers whose livelihoods depend on the health of their crops, planting by the phases of the moon is still common in some rural areas, she said.

Lunar Superstitions Provide Comfort

The Farmers' Almanac, for example, advises planting crops that are valuable because of the parts that grow above ground (such as corn and wheat) while the moon is waxing, so that the moon pulls the plant out of the ground while it grows bigger.

Conversely, it advises planting root crops (such as turnips and yams) while the moon is waning so that the diminishing moon helps the vegetables grow deep into the ground.

She's also seen scientifically-trained physicians refuse to castrate livestock during certain phases of the moon because they think they'll bleed out. They've never seen documentation or evidence supporting that notion, she said, but cite anecdotes from their uncles or older family members.

Risks run high in matters of health and agriculture, and moon myths ease the fear.

"There's a comfort factor that accompanies authority that extends back in time," she said. "If your feeling is that you are exerting a level of control and authority, that can reduce an element of anxiety."

ABC News' Liam Berkowitz, Chris Francescani and Brittany Bacon contributed to this report.