User comments on climate stories: impacts of anecdotal vs. scientific evidence

Abstract

Stories about climate change garner passionate comments from readers, ranging from acclaim to invective. This research is the first to investigate the effects of the rhetorical strategies of deploying anecdotal versus scientific evidence in comments. A between-subjects experiment with a U.S. adult sample (N = 363) tested whether user comments that support or contradict a climate news story, using either anecdotal or scientific evidence, have an effect on message reception. Individual difference variables in audience members have been shown to moderate the effects of comments in previous research. Findings show that political ideology is an important moderator of effects, particularly on the perception of climate change risk and story credibility. And when looking at the reactions of people who have low need for cognition and are highly conservative, climate uncertainty was diminished when anecdotal evidence appeared in comments. Taken together, these findings indicate that, in the context of climate change communication, comments from users can influence whether a climate story is perceived as credible by certain readers and can also disrupt a story’s intended message, particularly if comments attempt to invoke scientific proof for their claims.