Do users adopt extremist beliefs from exposure to hate subreddits?

Social media offers an avenue for like-minded individuals to interact in ways that were previously not possible. Yet, it can also be a breeding ground for hate and extremism to spread. Despite research into hate speech on social media, its influence on users adopting extremist beliefs is less understood. In this study, we use causal analysis to quantify extremist adoption resulting from users becoming active in hate online communities known as subreddits. Using an interrupted time series research design, we compare users who became involved in hate subreddits (treatment group) to those who did not (control group). This analysis is reproduced across ten different subreddits covering four different topics: Alt-Right, Racism, Sexism, and Fat-Shaming. From these analyses, we uncover a causal link between a user becoming active in a hate community and using more hate speech both within hate subreddits and across the wider platform. The results are consistent and replicate across communities. Our findings are tentative evidence that users adopt extremist ideas from exposure to hate subreddits.