Algorithmic social media use and its relationship to attitude reinforcement and issue-specific political participation – The case of the 2015 European immigration movements

Selective exposure to likeminded political viewpoints on algorithmic social media platforms is considered a potential source of polarization of public opinion. We still know little about the proposed mechanism or how potential reinforcement of specific attitudes affects citizens’ political behavior, especially in a nonelectoral context. Focusing on the issue of immigration during the refugee influx to Europe in autumn 2015, this study investigates the effects of social media usage on attitude reinforcement, connecting it to political participation in refugee-related activities. A panel study conducted among Danish citizens (n = 847) reveals that frequent social media usage reinforces existing attitudes and mobilizes political participation. However, citizens who become more extreme in their attitude toward immigration over time are found to be less likely to become politically active regarding this specific issue.