In consensus we trust? Persuasive effects of scientific consensus communication

Scholars have recently suggested that communicating levels of scientific consensus (e.g. the percentage of scientists who agree about human-caused climate change) can shift public opinion toward the dominant scientific opinion. Initial research suggested that consensus communication effectively reduces public skepticism. However, other research failed to find a persuasive effect for those with conflicting prior beliefs. This study enters this contested space by experimentally testing how different levels of consensus shape perceptions of scientific certainty. We further examine how perceptions of certainty influence personal agreement and policy support. Findings indicate that communicating higher levels of consensus increases perceptions of scientific certainty, which is associated with greater personal agreement and policy support for non-political issues. We find some suggestive evidence that this mediated effect is moderated by participants' overall trust in science, such that those with low trust in science fail to perceive higher agreement as indicative of greater scientific certainty.