The Causal Effects of Political Incivility in Social Media Discussions

Political discussions serve many important functions in democratic societies, but increasingly occur on social media where incivility pervades. How does incivility in online political discussions impact conversational dynamics and outcomes? Using a novel research platform, we perform a preregistered experiment testing incivility’s causal effects in online political discussions. Participants use a mobile application to access a social media feed manipulated to vary in political incivility, with discussions driven by synthetic users powered by GPT-4. Participants experiencing the politically uncivil feed reported less comfort sharing views and were less likely to comment on political posts but paradoxically created more original posts. Their content also contained more hostile features such as profanity and insults. Furthermore, exposure to political incivility led to more negative views of out-party voters while in-party ratings remain unchanged. These findings highlight how uncivil political discussions on social media simultaneously discourage open expression while fueling hostility.