Friday the 13th: Why Humans Are So Superstitious

Despite having well-developed brains, complex technologies and centuries of scientific progress, the human species remains a fearful, superstitious lot. And what better day to revisit the nature of superstition than Friday the 13th?

Superstition, it seems, is one thing that binds all of humanity throughout history and across cultural divides. Anthropologist Claude Lévi-Strauss once wrote that superstitions and belief in magic "are so frequent and so widespread that we should ask ourselves if we are not confronted with a permanent and universal form of thought."

Even in the modern world, superstitions hold immense sway over people's daily lives. "Several surveys of Americans suggest that roughly half say they are at least slightly superstitious," said Stuart Vyse, professor of psychology at Connecticut College. "A 2007 Gallup poll found that 13 percent of Americans would be bothered by staying on the 13th floor of a hotel. Nine percent would be bothered enough to ask for a different room." [13 Freaky Facts About Friday the 13th]

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The root of superstition is a lack of control, according to Vyse, the author of "Believing in Magic: The Psychology of Superstition" (Oxford, 2013). "Generally, [superstition] is aimed at achieving greater control," Vyse told LiveScience. "When something important is at stake yet the outcome is uncertain, then superstitions are likely to be used to fill the gap and make us feel more confident."

The gamut of superstitions

Superstitions, like the humans who believe in them, are a wildly diverse group. From professional athletes who cherish so-called lucky socks to the ancient use of talismans called nazars to ward off a malevolent stare known as "the evil eye," the range of superstitions can be mind-boggling. 

"I had a friend in graduate school who believed that his fingernail clippings and those of his family members might fall into the wrong hands and be used to commit malevolent magic against them," Vyse said. "He collected the clippings in a special bowl, and while reading late at night, he chewed them up and swallowed them. I contacted him 20 years later, and he reported that he was still doing this, though his family refused to give them their clippings." [The Surprising Origins of 9 Common Superstitions]

Superstitions about nail clippings appear to be relatively common; even artist Pablo Picasso was known to save his nail clippings and locks of hair. And he wasn't the only famous person with a superstitious bent: Actress Jennifer Aniston always steps onto a plane with her right foot first, according to the Los Angeles Times. And apparently Coldplay frontman Chris Martin always brushes his teeth before going onstage, and actress Cameron Diaz reportedly knocks on wood all day, every day.

Superstition and mental illness

Stories like these bring to mind obsessive-compulsive disorder or other mental illnesses, but Vyse and other sources report there is little scientific evidence of a link between superstitions and behavioral disorders.

"The closest [disorder], on the surface, is obsessive-compulsive disorder, but there seems to be no direct connection," Vyse said. "Scales measuring magical ideation [magical thinking] sometimes include items that are similar to superstition, and high scores on the scale are correlated with subsequent mental illness. However, magical ideation includes many other concepts (hearing voices) that are not related to superstition. So, at this point, no clear connection between the two has been established."

Superstitions affect different people to varying degrees, Vyse noted. "Women tend to be more superstitious," he said. "In addition, people who are more anxious, depressed or have an external locus of control (believe they are not the masters of their fates) are more likely to be superstitious."

Even hard-core skeptics can occasionally fall prey to superstitions. "If the stakes are high and the effort involved is low, many rational people will say they don't believe — but they 'don't want to take a chance,'" Vyse said. "But most important is socialization. If we come from a superstitious family, it is more likely we will be superstitious."

Superstitious animals

As if to prove how hardwired humans are to associate random things (like "lucky" socks) with success or failure, studies have shown that humans aren't the only animals prone to superstitious beliefs. In a famous experiment from 1948, renowned psychologist B. F. Skinner was able to condition pigeons to behave a certain way with the belief they would then receive food from an automated food hopper — even though the food actually appeared at regular timed intervals.

"The conditioning process is usually obvious. The bird happens to be executing some response as the hopper appears; as a result, it tends to repeat this response," Skinner wrote in the Journal of Experimental Psychology. "One bird was conditioned to turn counter-clockwise about the cage, making two or three turns between reinforcements. Another repeatedly thrust its head into one of the upper corners of the cage. A third developed a 'tossing' response, as if placing its head beneath an invisible bar and lifting it repeatedly."

Despite their irrational basis, superstitions can be helpful in a few circumstances. "Superstitions centered around luck in a skilled activity (putting a golf ball) have been shown to improve performance," Vyse said. "However, to the extent that belief in luck prolongs people's attempts at problem gambling, or belief in psychic powers encourages the use of Internet psychics — they can be harmful."

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