It was, of course, scientifically impossible for the legendary Curse of the Billy Goat—which dictated that the Chicago Cubs would never win the World Series—to have affected the outcome of games in the 2016 postseason. To give credence to the curse (laid on the team in October 1945 by an angry bar owner whose smelly mascot goat was evicted from Wrigley Field) is irrational and the very definition of magical thinking. And yet, as the Cubs once again sought to end their 108-year World Series Championship drought, lifelong fans like Michael Pardys struggled—and failed—to remain rational.

“Intellectually, I know this is a really good baseball team,” Pardys, 66, an attorney and Wrigley Field season-ticket holder, said in the weeks before the Cubs won the Series with their 8-7 victory over the Cleveland Indians on Wednesday night. “They won 103 games in the regular season and there’s no reason at all that they shouldn’t win. But there’s a feeling of doom that hangs over me. Something always intervenes.” To fend off his sense of dread, and to try to help his team overcome decades of ill fortune, Pardys wore the same Cubs hat and sweatshirt to every game he attended this fall and performed a ritual handshake with his wife Sandy and a third fan before the first pitch. “I feel really silly saying this,” he admitted, “but I somehow feel that the whole thing is really delicately balanced, that anything can change it.”

Pardys may be sheepish about it, but when he gives in to his superstitious impulses he is acting on common psychological tendencies that are shared by a lot of other intelligent, emotionally stable adults. Indeed, the intuitive thinking that prompts many superstitious behaviors may actually carry an evolutionary advantage. “You would never want to undo the processes that give rise to superstitious thinking,” says Jane Risen, an associate professor of behavioral science at the University of Chicago Booth School of Business who studies judgment and intuitive belief formation.

Those processes, Risen says, involve what’s known as “System 1 thinking,” from the dual process model of thinking as developed and popularized by psychologist Daniel Kahneman. In that model System 1 offers quick, intuitive answers to judgment problems that are sometimes essential for survival, and System 2 analyzes and may correct what System 1 proposes. While an otherwise rational person’s embrace of superstition might seem like a failure of System 2, Risen suggests in her work that people like Pardys “recognize that their belief is irrational, but choose to acquiesce to a powerful intuition.” To put it another way, System 2 does its job and points out that wearing a certain sweatshirt cannot possibly affect the play on the field, and the fan simply rejects it.

The length of the Cubs’ ordeal—more than a century—and the number of people who have shared the pain are also factors in fans’ propensity for superstitious rituals. “The intuitive properties of a long-held superstition are likely to be much stronger,” Risen says. “And the fact that other people believe it means that it’s entertained as a possibility. With the Cubs, you pay attention to this lore because everybody else is paying attention to it.”

And because, well, there has to be a reason the Cubs had not won the World Series since 1908—doesn’t there? Research shows that in our desire to understand why things happen and to deal with the uncertainties of life, people often resort to what is called causal reasoning, which can lead us to see patterns and connections that don’t exist. If, for example, the Cubs had won the 1946 World Series (or any World Series in the 1950s or 1960s), the Curse of the Billy Goat would be long forgotten. But they didn’t—and though there are thousands of baseball-related reasons for the drought, evoking the curse is, in its way, the most appealing. Chicago native and lifelong Cubs fan Darian Martyniuk, 49, who has his own elaborate set of game-day rituals, understands the simple pull of superstition. “It’s very tempting and it’s very comforting,” he says, “in the same way that I suppose religious faith is comforting to a lot of people.”

Along with the anxiety relief that can come from superstitious behaviors, another psychological tendency at work in Wrigley Field is confirmation bias. “The way we think about things,” Risen says, “is we start with a hypothesis and we move forward with that. We look for confirmatory evidence. We don’t try to disconfirm.” So when Martyniuk, who says he is “slightly OCD (obsessive-compulsive disorder)” as well as superstitious, catches the same train to the game and enters through the same gate and wears the same hat and the Cubs win, it confirms his feeling that he is doing his part to help the team.

And when they lose, it is negative agency bias that often comes into play. Carey Morewedge, a social psychologist and associate professor of marketing at Boston University Questrom School of Business, has studied this common inclination and invokes another well-known championship drought to explain it. “The Red Sox had 86 years of no postseason success,” Morewedge says, “which was attributed to the 1919 trade that sent Babe Ruth to the Yankees. But when the Red Sox did win the World Series twice in a row, fans didn’t really attribute it to the players’ beards or Ted Williams’s ghost.” Instead, he says, the credit for the positive result went to the team. “But when it’s negative,” he adds, returning to the Cubs plight, “we say it was the goat.”

Or maybe it was the black cat—the one that walked between the Cubs dugout and the on-deck circle at Shea Stadium in September 1969, as a team with four future hall-of-famers was squandering what had been an 8.5-game lead over the Mets. Or maybe it was the hapless Steve Bartman, the ill-fated fan who snagged a foul ball during a 2003 National League Championship game against the Florida Marlins and was subsequently blamed for costing the Cubs the pennant and continuing the curse. The “Bartman ball” was eventually purchased by a Chicago restaurateur for more than $100,000 and blown up in a televised ritual.

Risen, discussing that event and the magical thinking that went into it, casually offers a new theory that could well have given Michael Pardys, Darian Martyniuk and lots of other Cubs fans something brand-new to worry about as the Cubs returned to the Word Series for the first time since the Curse of the Billy Goat was issued to face the Cleveland Indians.*

“If you think of this ball as the bad thing that happened, then yeah, there’s something very metaphoric about blowing it up,” she says. “But there’s a version where blowing it up puts it out in the world, and what you should have done instead was bury it.”

*Editor's Note (11/03/16): This story was updated after posting to reflect that the Chicago Cubs defeated the Cleveland Indians to win in the World Series.