Frequent commenters on Facebook are more likely to be interested in politics & to have more polarized opinions; also, people who comment on articles in the real world use more toxic language on average than the public as a whole

The Distorting Prism of Social Media: How Self-Selection and Exposure to Incivility Fuel Online Comment Toxicity. Jin Woo Kim, Andrew Guess, Brendan Nyhan, Jason Reifler. Journal of Communication, jqab034, September 3 2021. https://doi.org/10.1093/joc/jqab034

Abstract: Though prior studies have analyzed the textual characteristics of online comments about politics, less is known about how selection into commenting behavior and exposure to other people’s comments changes the tone and content of political discourse. This article makes three contributions. First, we show that frequent commenters on Facebook are more likely to be interested in politics, to have more polarized opinions, and to use toxic language in comments in an elicitation task. Second, we find that people who comment on articles in the real world use more toxic language on average than the public as a whole; levels of toxicity in comments scraped from media outlet Facebook pages greatly exceed what is observed in comments we elicit on the same articles from a nationally representative sample. Finally, we demonstrate experimentally that exposure to toxic language in comments increases the toxicity of subsequent comments.