Abstract
In 2016 the comment sections under Donald Trump's and Hillary Clinton's Facebook posts drew millions of comments. Who took part, how hostile were they, and was hostility rewarded? I study 5.2 million comments: every comment that could be retrieved from 730 posts on Trump's page during the Republican primaries (January to April 2016), and from 16 posts on the two candidates' pages on 1 October 2016. Commenters appear only as anonymised codes. A weighted sample of 111,925 comments was scored with an open toxicity classifier and checked against a dictionary measure applied to every comment.Participation was very unequal: the most active 1% of 1.1 million commenters wrote 31% of the comments. About one comment in ten was toxic, and the rate barely moved across the primaries, falling slightly on voting days. Toxicity was not rewarded: once the timing of comments is taken into account, toxic comments were as likely as others on the same post to receive at least one like. The heaviest commenters were no more toxic than occasional ones. On 1 October the two candidates' comment sections were equally toxic, but the 1,106 people who commented on both pages were more toxic on Clinton's page than on Trump's. Hostility in these spaces was widespread rather than concentrated among the most active.The files include the preprint and aggregate data (weekly and daily counts and rates, and the summary results behind the tables). No comment text or commenter codes are shared.Provenance and AI use. The data were collected with Netvizz for my doctoral research, before Netvizz closed in 2019. This paper builds on my doctoral thesis (Hotham 2021, University of Bath). The analysis and writing were completed in 2026. The analysis code and drafts of the text were prepared with the assistance of an AI system (Claude, by Anthropic), which was also used to review drafts. I checked the analysis and the text and take responsibility for both. Version 2 added this statement to the paper, and version 3 changes only the date on the title page; the findings are unchanged.
Cite
Hotham, T. (2026). Who Speaks in the Candidate's Comment Section? Participation, Toxicity and Reward on Donald Trump's and Hillary Clinton's Facebook Pages in 2016. Preprint, Zenodo. https://doi.org/10.5281/zenodo.23287106