Battle For Britain: Analyzing Events As Drivers Of Political Tribalism In Twitter Discussions Of Brexit

In the aftermath of the 2016 referendum on European Union (EU) membership, Britain was divided into identity groups (or tribes) of Leavers and Remainers. In this study, we investigate how Brexit tribalism-in the form of outgroup derogation-has unfolded over time on Twitter. We analyze data from 32 months of discussions (n = 9,027,822), using identity-based keywords as proxies for tribalism. First, we characterize the nature of the discussion by comparing language use patterns between tweets containing Brexiteer/Remainer and Brextremist/Remoaner keywords. We find that Brextremist/Remoaner are more commonly used in a derogatory way. We also find that all four group identity keywords are used more frequently over time, suggesting an increase in tribal interactions. Finally, we find evidence of a relationship between real-life Brexit events and spikes in tribal responses online. These findings provide compelling insights into the extent of tribal political behavior on social media. They are significant for furthering our understanding of tribalism as a central feature of information warfare campaigns that aim to divide societies.