Understanding the Effects of Message Complexity and Epistemic Uncertainty on Attitudinal, Cognitive, and Behavioral Responses to Messages About Microplastics

This study examined how message complexity and epistemic uncertainty affect attitudes toward science, information overload, and behavioral intention using a 2 × 2 factorial design. Although no main effects were detected, the interaction between complexity and uncertainty on information overload depended on intolerance of uncertainty (IU): uncertainty reduced information overload for low-IU individuals but increased it for high-IU individuals. Moreover, the conditional indirect effect of uncertainty on behavioral intention through information overload was significant under high message complexity at specific levels of IU. When message complexity was low, this indirect effect was not significant at any level of IU.