Influence of social media comments on opinions about news

In the current age many people encounter news through social media. This mode of information acquisition is characterised by the presence of reader’s comments published together with the news. Previous studies have shown that these comments influence people’s opinion about the news, which raises questions about the vulnerability of public opinions. We developed an ecological task to replicate and investigate this phenomenon experimentally. In our task, participants were presented with headlines on important contemporary issues actually posted on Facebook, together with actual readers’ comments, in a display replicating the social media platform. Participants in two pre-registered studies run in different countries (USA, N = 220; Germany, N = 220) consistently adjusted their opinions in accordance with the sentiment expressed in the comments. The degree of opinion change was significantly greater when participants had weak pre-existing attitudes toward the topics and when they had low confidence in their initial opinions about the news. An exploratory analysis revealed greater susceptibility to social influence in less digitally mature participants. This study replicates under controlled conditions the powerful influence of online social media comments in shaping public opinion and points to some variables moderating this influence.