DescriptionThe present three-part study investigated the links between cognitive complexity, message processing, and extremity of attitudes. The focus of the first two studies was to create and validate a self-report measure of cognitive complexity. The development of a reliable and easy to administer instrument will further clarify the investigation in the area of cognitive complexity and message processing. In Study 3, social judgment theory was utilized to provide a theoretical framework for examining the relationship between cognitive complexity, message processing and outcome variables. Study 3 used a repeated measure design with two weeks between pre- and posttests. Participants were randomly assigned to one of the eight different experimental groups, varying by topic (alcohol vs. sleep) and message evidence (narrative vs. statistical; two message replication each), with a control group. The project concluded with analysis of the performance of the new measure and the potential role of cognitive complexity in health message design. The results confirmed previous findings that cognitive complexity is not a static trait variable, but rather a function of the interaction of psychological, contextual, and environmental variables. In addition, results from this study indicated that although message evidence types do not have a direct impact on attitudes and behaviors, some do affect message perception variables. Implications and directions for future research are discussed.