Does Misinformation Have Spillover Effects on Unrelated Health Behaviors? Promising Null Results from a Longitudinal Study of U.S. Adults

In the wake of the COVID-19 pandemic, a critical question for health communication is whether misinformation exposure and misperceptions about one health topic have far-reaching, or "spillover," effects on health behavior in general. The present longitudinal study of U.S. adults (T1 <i>n</i> = 1012, T2 <i>n</i> = 607) examines the potential effects of COVID-19 misinformation endorsement at T1 (Jul. 30-Aug. 12, 2020) on both topically related prevention behavior (COVID-19 vaccine intention/behavior) and unrelated behavior (exercise, alcohol consumption, vaping, and smoking) one year later, at T2 (Jul. 20-Aug. 12, 2021), controlling for behavior at baseline. We found misinformation endorsement negatively predicted related behavior (COVID-19 vaccination); it did not predict unrelated behaviors. These findings are consistent with behavior change theories and do not support spillover effects, suggesting false beliefs about a topic are unlikely to directly predict unrelated health behaviors. Implications for public health communication are discussed.