According to researchers at the University of Cologne, believing in luck-related superstitions boosts confidence and leads to better and faster performance in what you're doing.
Photo by andymangold.
The research consisted of four small experiments, according to Bad Science author and doctor Ben Goldacre:
In the first, they took 28 students, over 80% of whom said they believed in good luck, and randomly assigned them to either a superstition-activated or a control condition. Then they put them on a putting green. To activate a superstition, for half of them, when handing over the ball the experimenter said: "here is your ball. So far it has turned out to be a lucky ball". For the other half, the experimenter just said "this is the ball everyone has used so far". Each participant had 10 goes at putting on the green, trying to get a hole-in-one from a distance of 100 cm: and lo, the students playing with a "lucky ball" did significantly better than the others, with a mean score of 6.42, against 4.75 for the others.
Likewise, each of the remaining three experiments revealed some sort of performance boost from "luck". How well this translates to life probably varies, but as Goldacre put it:
What's interesting is that superstition works, because it improves confidence, lets you set higher goals, and encourages you to work harder. In a lab. You now know everything you need to decide if this applies to your life.