r/LinguisticPolarization: Lexical and Semantic Variation between Political Communities on Reddit

Abstract

Political Polarization is a growing issue in the US, and undermines the stability of our democracy. Linguistic Polarization is the manifestation of political polarization in the language used by ideological groups, and can serve to deepen ideological divides. In this thesis, we investigate two forms of linguistic polarization: lexical polarization and semantic polarization. Lexical Polarization focuses on vocabulary differences between ideological groups, while semantic polarization captures shifts in the meanings of words. We examine four corpora of Reddit data, collected from r/democrats and r/Republican in 2019 and 2023. We use frequency and embedding-based analysis methods to characterize the language polarization in our datasets. This allows us to identify polarizing issues and political figures, and identify any communication gaps between the two sides of the ideological spectrum that may be exacerbating overall polarization.