Why do so many Americans believe in luck against all reason? Psychologists tell us that sometimes, feeling lucky can actually improve performance.

You might be surprised to learn that around a quarter of Americans are superstitious. When we think about it rationally, the idea of luck may seem silly, but there are a lot of people throughout history who made significant decisions based on superstitious beliefs.

The world’s largest car manufacturer, Toyota, changed its name from Toyoda in the 1930s because the number of brush strokes was more auspicious in Japanese culture. Donald Trump, who has been unwavering in his belief in his own ability, describes himself as a very superstitious person. He is known to throw a few grains of salt over his shoulder after eating.

It’s hard to understand why large numbers of people would choose to believe in an invisible, unmeasurable force over their own agency. And we know that belief in luck has little basis in reality. So why are so many successful people believers?

“Luck is a slippery subject,” says Maia Young, associate professor at the UCLA Anderson School of Management. “It’s a hard thing to prove or disprove.”

Prosperity is not always merit-based, which leads many to search for answers as to why some deserving people fail while some undeserving succeed. While there is nothing objectively special about a lucky penny, lucky charms really do seem to work.

“There is no real tangible thing we can call luck,” says Joseph Mazur, mathematician and author of Whats Luck Got to Do with It? “But we create that tangible thing by transferring it to an object.”

And those lucky objects afford us the feeling of a security blanket. “Lucky charms create an illusion of control for the person who believes in them,” says Stuart Vyse, psychologist and author of Believing in Magic: The Psychology of Superstition.

In studies of lucky charms, people perform better on tasks when they have a lucky charm with them. In one study in 2010, researchers had students putt a golf ball. Half the students were told that the golf ball they were using was lucky. The students who thought they were putting with a lucky ball were better at it than students told they were using a regular ball.

As part of the same study, a group of students who had lucky charms were recruited for a series of memory tasks. Half the students were allowed to keep their lucky charms with them, and the other half had their charms taken away. The students who were allowed to keep their charms performed better.

“In a skilled activity, lucky charms boost confidence for people who believe in them,” explains Vyse. “Even though many people might not know how their lucky charms actually work, it is not a bad idea to carry a charm for added confidence,” says Young. “It is a low cost belief,” she explains.

Personality and attitude play into luck as well. In her research, Young finds that optimism is positively associated with luck. “If someone believes that they are lucky, and believes that good things will happen, they will try harder at a task,” she says.

“When people view themselves as lucky, they are more likely to choose and persist at challenging tasks,” explains Young.

That persistence can have a self-reinforcing effect. The more challenging tasks people take on, the more chance there is they will succeed at some of them, giving them a sense that they are indeed lucky.

“A generally positive attitude towards life also makes it seem like more happy events occur for a person,” says Vyse. When someone has a sense that things are going their way in general, it makes for better interactions with other people. Those improved relationships can lead to more opportunities down the line if one of those friends becomes a useful connection for work or a romantic partner.

While it is not rational to put stock in luck, studying the psychology behind the belief can begin to explain why some people end up at the top while others end up at the bottom.

Read more: https://www.theguardian.com/lifeandstyle/2016/jul/25/psychology-donald-trump-win-luck-superstition