How opposing ideological groups use online interactions to justify and mobilise collective action.

The purpose of this pre‐registered study was to investigate how different ideological groups justified and mobilised collective action online. We collected 6878 posts from the social media accounts of pro‐Black Lives Matter (n = 13) and anti‐Black Lives Matter (n = 9) groups who promoted collective action in the month after George Floyd's murder and the Black Lives Matter (BLM) protests and counter‐protests. We used content analysis and natural language processing (NLP) to analyse the content and psychological function of the posts. We found that both groups perceived their action as 'system‐challenging', with pro‐BLM accounts focused more on outgroup actions to mobilise collective action, and anti‐BLM accounts focused more on ingroup identity. The reverse pattern occurred when the accounts were attempting to justify action. The implications are that groups' ideology and socio‐structural position should be accounted for when understanding differences in how and why groups mobilise through online interactions. [ABSTRACT FROM AUTHOR]