Quarterback Patrick Mahomes wears the same pair of red underwear on every National Football League game day. After donning the undergarment during a successful first season in 2017, Mahomes continued to put it on before each game, believing it would bring him good luck. “If we’re on a hot streak, I can’t wash [the pair].... I just got to keep it rolling,” he said in an interview with ESPN.
Mahomes’s game-day uniform is a classic example of a superstition, a ritual that links certain actions or items to unrelated outcomes without any basis in reason or evidence. Superstitions often center around the belief that an object, person or situation is imbued with magical power that makes good or bad things happen.
Counterintuitively, superstitions persist today, sometimes among the most seemingly rational of people, in spite of our purportedly robust ability to understand the world around us.“I’m going to be a little radical—I think we are all basically superstitious all the time,” says Erol Akçay, a theoretical biologist at the University of Pennsylvania, who has studied how superstitions may spread.
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A psychology study published in 2024 suggests that very few people show a complete lack of superstitious beliefs or practices. So why do we remain superstitious, even though it is clearly irrational and could lead us astray? It turns out superstitions may provide certain psychological benefits.
One reason may be that indulging a superstition can alleviate stress. In a 2018 study by researchers at the University of Singapore, a subset of the 114 participants were randomly assigned to complete a stressful task—an interview and mental arithmetic problem performed in front of a panel of two judges—or a no-stress control task. Some of the participants were given a pen they were told had proven lucky for others, while others received a pen without any such commentary. Those with the “lucky” pen experienced less anxiety and rated their own performance more positively.
The benefit of a superstition may go beyond just emotional comfort: In 2010, psychologists at the University of Cologne found that invoking good-luck-related superstitions—by telling participants phrases such as “I keep my fingers crossed” or giving them a “lucky charm”—measurably improved performance in activities as varied as golfing, motor dexterity, memory games and anagram puzzles.
The researchers suggest that participants did better when superstitions were invoked because they experienced an increase in self-efficacy, a belief in their ability to succeed at their goal. Participants primed with superstitious comments reported a greater sense of self-efficacy compared with a control group.
Superstitious beliefs can also amplify placebo effects. A 2021 study in the journal Cognitive Processing hypothesized that people who are more superstitious would get a bigger boost from a placebo treatment during a memory task. The authors split 104 participants into placebo and control groups. After assessing everyone’s superstitious tendencies, they gave the participants in the placebo group colored water and told them it enhanced memory. Highly superstitious people who drank the supposed memory elixir recalled more words than their less superstitious counterparts—and the opposite was true for those in the control group, who drank a plain glass of water. Even though superstitions have no magical powers, the psychological impacts of believing in them can tangibly affect outcomes.
Yet superstitions also come with costs. Whether you cross the street to avoid walking under a ladder, knock on wood for good luck or perhaps throw salt over your shoulder to ward off evil spirits, those actions take time, thought and effort. And the investment may go unrewarded: a properly secured ladder, for example, poses no actual threat. Why would people embrace such unfavorable trade-offs in the first place?
An analysis published in 2007 in Human Nature suggests that superstition is the inevitable result of humans using what is called an adaptive learning strategy. Our species learns by observing the world, identifying patterns and adapting beliefs accordingly. We need rules to distinguish between real patterns and randomness, however. Those rules must account for both the cost of a false belief that one thing causes another (the essence of superstition) and the cost of failing to recognize a relationship that really does exist.
While superstition involves mistaken interpretations and wasteful rituals, failing to notice true cause and effect — not recognizing, for example, that a certain plant is poisonous or that a type of cloud precedes dangerous weather — can exact an even higher price. In balancing the risks of both types of errors, people are sometimes bound to misjudge a situation.
A study published in 2009 in the Proceedings of the Royal Society B: Biological Sciences examines the conditions under which superstitiousness aids survival. When making decisions in uncertain environments, the researchers find, it can be advantageous to err on the side of forming incorrect cause-and- effect linkages. This is particularly true when the risk from missing a genuine threat is much higher than the risk from a false alarm. Even if the rustling of a bush usually results from wind, if it is sometimes a lion, you are better off acting as though every unsettling noise is life-threatening.
On the other hand, when acting on superstition is relatively costly, the benefits of holding these beliefs might start to fade. In modern life, we rarely confront high-stakes survival situations, and science and technology offer powerful means to interpret and influence events, putting superstitiousness at a disadvantage.
“[These beliefs] serve a certain function,” says Boris Gershman, an economist at American University, who has theorized about the origins of superstitions. “A corollary of that is we should expect [superstitions] to dissipate once… the function they are supposed to perform is fulfilled in other ways.”
But superstitions might be slow to fade if they continue to provide comfort and alleviate stress, even if they afford no obvious benefit. “These beliefs can be quite persistent,” Gershman says. “You learn something from your parents, and your children learn it from you. That is a powerful thing.”