Effects of the valence and argument substantiveness of others' comments on viewers' validation of and attitudes toward pseudo-scientific claims

This study examines how the valence and argument of comments affect viewers' attitudes toward and validation of a pseudo-scientific claim. We developed and tested a hypothesized model based on the elaboration likelihood model. Participants watched a video that introduced pseudo-scientific claims with others' comments on the same screen. We assigned participants (n = 646) to a control condition with no message presentation and a message condition, with the message condition divided into four conditions based on a combination of valence and substantiveness of the comments. Structural equation modeling analysis revealed that valence affected both heuristic and systematic thought, while substantiveness influenced systematic thought. The negativity of the comments not only suppressed the positive impressions, which were irrelevant to the content, but also facilitated the examination of the reasoning for the pseudoscience claims in the video. Including substantive content in the comments also led to an examination of the rationale for pseudoscience claims. The model also showed that positive impressions irrelevant to the content increased validity judgments, the final positive attitude, and agreement to the pseudo-scientific claim, while examination of the rationale for the claims decreased them.