This study investigated whether the processing and evaluation of online news content can be influenced by Likes and peer-user comments. An online experiment using a Facebook-like website explored how Likes, positive comments, negative comments, or a combination affected reader processing. Results showed negative comments significantly affected readers' opinions, inducing more negative attitudes, lowering share intent, reducing agreement with ideas, lowering perceived public attitude, and decreasing credibility. Likes had no effect. The persuasive effect of negative comments, which comprised subjective, emotive, and fallacious rhetoric, is discussed in terms of negativity bias, perceived expert authority, and cognitive heuristics.

Arnout B. Boot, Katinka Dijkstra, Rolf A. Zwaan