Stephan Winter, Anne L. Vos, Paola Remmelswaal, Peter Neijens

• Online communication channels provide rich opportunities for public opinion expression, and the act of posting may lead to an internalization of the expressed views. This research investigated whether such self-effects are affected by feedback comments and whether this influence is stronger in social network sites than in anonymous online forums. In an experiment manipulating valence of feedback and the media context, 161 participants were asked to express their opinion on a current topic. Results showed limited effects of feedback: Negative comments tended to reduce internalization among participants with non-extreme prior attitudes, but this was independent from the media context.