Objective: The study of vaccine hesitancy identifies parental decisions to delay childhood vaccinations as an important public health issue, with consequences for immunization rates, the pursuit of nonmedical exemptions in states, and disease outbreaks. While prior work has explored the demographic and social underpinnings of parental decisions to delay childhood vaccinations, little is known about how the psychological dispositions of parents are associated with this choice. We analyze public opinion data to assess the role of psychological factors in reported parental decisions to delay childhood vaccination. Rationale: We anticipate that parents with certain psychological characteristics will be more likely to delay childhood vaccination. Specifically, we explore the roles of conspiratorial thinking, dispositions towards needle sensitivity, and moral purity; expecting that parents with high levels of any of these characteristics will be more likely to delay vaccinating their children. Method: In an original survey of 4010 American parents weighted to population benchmarks, we asked parents about delay-related vaccination behavior, demographic questions, and several psychological batteries. We then developed a vaccination delay scale and modeled delay as a function of conspiratorial thinking, needle sensitivity, moral purity, and relevant demographic controls. We then re-specified our models to look specifically at the predictors of delaying HPV vaccination, which has a low uptake rate in the United States. Results: Controlling for other common predictors of hesitant behavior, we find that parents with high levels of conspiratorial thinking and needle sensitivity are more likely to report pursuing alternative vaccination schedules. When analyzing the specific decision by parents to delay HPV vaccination, we find that tendencies towards moral purity and, in turn, sexual deviance are also associated with vaccine seeking behavior. Conclusion: Parental decisions to delay childhood vaccinations are an important public health concern that are associated with conspiratorial thinking and needle sensitivity.
