From carefully avoiding cracks in the pavement to saluting every magpie that you meet, superstitious behaviour is really common. But why do we have superstitions? Where do they come from? And are they helpful or harmful?  To find out, our presenter Ginny Smith talks to Stuart Vyse, former professor of psychology at Connecticut College and author of Believing in Magic: The Psychology of Superstition. Ginny also chats to Laramie Taylor, professor of communication at the University of California Davis, who explains how superstition and magical thinking is linked to being a fan of both fiction and sports. Episode credits: Presented and produced by Ginny Smith. Script edits by Matthew Warren. Mixing and editing by Jeff Knowler. PsychCrunch theme music by Catherine Loveday and Jeff Knowler. Art work by Tim Grimshaw. Relevant research and writing from our guests includes: Magical thinking and fans of fictional texts and Sports Fans and Magical Thinking: How Supernatural Thinking Connects Fans to Teams, both by Laramie Taylor and discussed in the podcast. Do Superstitious Rituals Work?, an article at Skeptical Inquirer in which Stuart Vyse discusses some of the work mentioned in this episode. How Superstition Works, an extract from Vyse's book Believing in Magic: The Psychology of Superstition, published at The Atlantic.