Why is Brexit So Polarizing and What We Can Do About it

Recent studies examining the psychological aspects of political polarization in the US have pointed to systematically different moral profiles possessed by Liberals and Conservatives, leading to divergence in political reasoning and discourse (Day et al. 2014; Feinber & Willer, 2015). In the British context, the contemporary debate around the Brexit referendum and its aftermath has been found to be highly polarized (Maher et al. 2018; Murray 2018). In this research, we focus on political ideology and the extent to which Liberals and Conservatives in the UK view Brexit in different terms. Specifically, we investigate the degree to which the argumentation surrounding Brexit is explained by Conservatives and Liberals relying on different moral foundations (Graham et al. 2009,2011). In an online survey, respondents report their reasoning for their Brexit vote as well as their underlying reasons for their views on the possibility of a second referendum. We use machine learning techniques to classify these arguments and estimate the degree to which they reflect different moral foundations. Second, based on the textual data collected, we craft messages highlighting Conservative/Liberal moral foundations, and use a block design to test whether matching moral foundations with respondents’ ideology affects persuasion regarding the possibility of a second Brexit referendum, as well as own Brexit vote, should a second referendum take place. Our results allow for a better, and more nuanced, understanding of the polarization surrounding Brexit, by exploring the relationship between moral values, ideology, and persuasion.