The project focuses on how we react as bystanders when exposed to online political hostility. The project hypothesize that such cyber-bystander decision-making is shaped by:

• factors at the level of message content (ambiguity and severity of hostility),
• bystander characteristics (political attitudes; identification with victim),
• situational circumstances (perceptions of responsibility and costs of reacting) and
• online context (type of social media platform; encouragement of pro-social reactions).

Further, the project hypothesizes that pro-social bystander reactions to online political hostility may encourage bystander mobilization in the short run by lowering the costs of reacting and ambiguity of the situation and increasing a sense responsibility, and alter norms of apathy and civility in the longer run.

And that pro-social bystander reactions can be encouraged through communication campaigns and the design of social media platforms.