Are conspiracy theories truly more prevalent and influential today, or does it just seem that way? The research isn’t clear. Nancy Rosenblum and others see evidence that belief in conspiracy theories is increasing and taking dangerous new forms. Others disagree. But scholars generally do agree that conspiracy theories have always existed and always will. They tap into basic aspects of human cognition and psychology, which may help explain why they take hold so easily — and why they’re seemingly impossible to kill. Once someone has fully bought into a conspiracy theory, “there’s very little research that actually shows you can come back from that,” says Sander van der Linden, a social psychologist at the University of Cambridge whose research focuses on ways to combat misinformation. “When it comes to conspiracy theories, prevention is better than cure.”