Today, St. Patty’s day is an excuse to start drinking early and stop only when seeing straight becomes a chore. A common symbol of this festive day is the clover, and paper versions of the plant can be bought at dollar stores nation-wide. While many view this icon as a good luck charm, researchers have found new evidence that there may be more to this little clover than meets the eye.

Centuries ago, although no one agrees on when, the Celts took a liking to the Trifolium, or white clover. It was widely respected for its three leaves, which symbolized balance, something the Celtic people highly valued. When Saint Patrick used the easily sustainable plant to teach the people of Ireland about Christianity, its popularity grew. He told them the three leaves represented the Holy Trinity: the Father, the Son, and the Holy Spirit.

The fourth leaf was said to represent God’s grace, so people valued these odd plants very highly. As time progressed, the leaves took on other meanings, like faith, hope, love and luck. Today they each represent a different element of luck: respect, love, wealth and health.

But even those with lots of wealth and health still want luck. Athletes, for example, are some of the most superstitious people around, with many teams and individuals having their own lucky traditions. “We always play the same playlist of music in the change room before games,” says Heather Malazia, coach for the Laurier women’s soccer team.

“At the beginning of every season, each girl picks one song that they want on the list and we listen to it before every game. We use this as a team bonding exercise and it gets us pumped up for the game. It’s superstitious and we don’t want to ever switch it up.”

Although belief in luck isn’t new by any means, researchers today are still unclear about how it functions. A study released last July from the University of Cologne in Germany examined how subjects performed when they believed something was lucky. The first test had 28 subjects all try putting. Each subject was given a ball. Researchers told some participants the ball had been used by everyone. They told others the ball had been lucky for everyone who had used it. In the second test, 36 different subjects were given a puzzle that required them to get balls to sit in tiny dimples in a board as quickly as possible. Again, some were wished luck while others received neutral instructions. The final test had new subjects participate in a mental test, once with their lucky charm tucked beside them and once without it.

In every case, anyone who had luck wished upon them or with them in some way did better than those who didn’t. Subjects who participated in the mental test were asked how they felt when they had their charm with them. Most reported feeling more comfortable and confident with the charm than without it.

Theories exist about how luck works, but no concrete evidence about how it affects the brain. A popular psychological theory is the Locus of Control, which describes a person’s thoughts about punishment and reward in their everyday life. Luck can be related to someone who has an External Locus of Control. This means they believe they don’t have control over a situation. Instead, they believe external factors are in control.

Generally, it is thought this belief can have a negative psychological impact. The person may fall into motivational and emotional depression feeling they have no control over their life.

However, something positive may happen to someone who believes their performance is based on luck. It’s called Reactance, which is an increase in motivation and emotional levels in an attempt to regain control of a situation.

Again, sports provide a good explanation. An athlete enters an event thinking they may not be able to win so they bust out their favorite good luck charm. Something inside their brain triggers them to work harder, because it has conditioned itself to do so when the lucky ritual is done or object nearby. This happens because every other time they’ve done this same thing, they’ve won. These actions are most likely habitual, not conscious.

Some athletes are more superstitious than others, even those regarded as highly talented. Sidney Crosby is one of the most famously superstitious players in the National Hockey League. He does everything he can to avoid walking past his opponent’s change room, even in the Penguins’ home arena. He also wears a yellowing jock strap he’s had for years. The sweat stains on his lucky hat make his team’s name almost invisible. Michael Jordan was known for wearing his National Championship-winning shorts underneath his Bulls shorts at each of their games. Serena Williams won’t change her socks if she’s winning a tournament.

Given the mounting evidence that luck may actually have some validity, finding your own charm may be tempting. With exams quickly approaching, you may want to finish studying by picking up a luck charm, or at least digging out some old St. Patrick’s Day decorations. How it actually works may still be uncertain, but what have you got to lose?
Well, other than a little bad luck.