It might have been "The Distorting Prism of Social Media: How Self-Selection and Exposure to Incivility Fuel Online Comment Toxicity" by Jin Woo Kim et al. [1][2]

1: https://academic.oup.com/joc/article-abstract/71/6/922/63636...

2: https://drive.google.com/file/d/1rJ20sca3fg6epXwVbGj7HdNfCH4...