Estimating the causal effects of cognitive effort and policy information on party cue influence

Abstract Party cues can influence public opinion, but the extent to which they do so varies dramatically from context to context. Why? The long‐standing theory that party cues function as “heuristics” provides an answer, predicting that variation in exposure to policy information, a propensity for effortful thinking, or both causally affects the influence of party cues. However, this prediction has escaped decisive empirical testing to date, leaving in its wake a string of mixed results. Here we characterize the challenges that limit previous tests, and report on two large‐scale experiments designed to overcome them. We find that exposure to policy information causally attenuates the influence of party cues, but engagement in effortful thinking per se does not. Our results advance understanding of the “when” and “why” of party cue influence; clarify a number of previously ambiguous findings; and have broad theoretical, methodological, and normative implications for understanding the influence of party cues.