Christopher Bader is a sociologist at Chapman University in Orange, Calif., where he has three times been the principal investigator on the annual Chapman Survey of American Fears. The survey asks adults about dozens of topics, such as nuclear war, pollution, volcanic eruptions and zombies, and then ranks the terrors in order of prevalence. Dr. Bader also studies religion and conspiracy theories, and he finds these big issues often intersect. The most recent survey was published in October 2023. In an interview that has been edited and condensed for clarity, he discussed the latest findings.