Research on factors that encourage people to speak out online uses either experimental or observational data, and it is unclear whether patterns detected in one setting apply to the other. This project examines whether message incongruence and incivility influence the likelihood of commenting on social media posts about politics in both controlled and naturalistic settings. An online experiment on American adults using a mock Facebook page (Study 1, N = 424) showed that incivility decreased commenting when the original comment was pro-attitudinal but had no effects when it was counter-attitudinal and that incivility directly depressed commenting (i.e., unmediated via anger), but increased it indirectly through anger. An observational study on Spanish Twitter users (Study 2, N tweets = 4,153) demonstrated that in a naturalistic setting, there were more pro- than counter-attitudinal comments in response to the original tweet, and incivility was not associated with the desire to speak out. The implications are discussed.
political expression; message incongruence; incivility; social media; anger; third-person effect