Around the world, people today are celebrating Halloween with costumes, candy, celebrations of the strange and frightening, and this charming Google homepage. By tomorrow, though, costumes will be discarded, candy supplies diminished (and stomachs bloated), and pumpkins left on the stoop to rot until the neighbors complain. In other words, Halloween will disappear from most people’s minds until next October. But there’s a more serious side to Halloween: the persistence, around the world, of belief in the occult and the paranormal. When the trappings of Halloween have passed, what remains of the beliefs associated with it?

Somewhat surprisingly, such beliefs persist in large numbers even today. A 2003 Harris Poll reported that 51 percent of Americans believe in ghosts. Other surveys have shown that roughly one-third of people believe in haunted houses. What’s behind these high numbers? It’s not clear that mainstream religious belief has a major impact (in fact, one 2004 study found a negative correlation between religious belief and paranormal belief.) Nor do these surveys signal the triumph of the flat-earthers: A 1993 paper reported that people who believe in the paranormal “neither distrust nor reject science” and “do not hold negative feelings about modern technological society.” Part of the answer may lie in what some researchers describe as specific logical shortcomings. As one 2007 study put it, belief in the paranormal does not indicate a general inability to reason, but rather a more specific misunderstanding of randomness and chance. Keep that in mind this Halloween, should you see something that seems to defy belief: It could be simple misperception, or maybe you’ve had too many pumpkin beers.