Misleading political advertising fuels incivility online: A social network analysis of 2020 U.S. presidential election campaign video comments on YouTube

In the 2020 U.S. presidential election, increasing misinformation-based political advertisements have circulated on video-sharing platforms, such as YouTube and challenged healthy political communication. This study investigates the social contagion of political incivility stemming from a misinformation-based campaign video posted by former U.S. President Donald Trump. Specifically, using dynamic network analysis and exponential random graph modeling, we explore and test three mechanisms (imitation, intergroup interaction, and reciprocity) for their role in the contagion of online political incivility. Contrary to previous findings, we show that online political incivility is not a fleeting occurrence but recurrent and sustaining given YouTube's promotional algorithms. Reciprocity is the primary mechanism that predicts the formation of uncivil politically-based interactions in YouTube comments. The findings provide implications for YouTube's content moderation mechanism and underline the need to reconsider the potential harm of promoting misinformation-based political campaigns through this platform.