Why More Social Interactions Lead to More Polarization in Societies
Markus Hofer, PhD Student at the Medical University of Vienna, Austria
Social connections have more than doubled over the past two decades, while societal opinions in Western countries have become increasingly polarized. Could these trends be connected? This talk presents a computational model of opinion dynamics in social networks that exhibits a striking phase transition: above a critical level of social connectivity, society undergoes an explosive transition toward strong polarization. The model, which realistically captures homophily and social balance, explains the observed rise in polarization as a direct consequence of increased connectivity. Introducing a small fraction of synchronized influencers changes the dynamics: the transition becomes continuous rather than explosive, but polarization emerges at even lower connectivity levels.
S. Thurner, M. Hofer, & J. Korbel, Why more social interactions lead to more polarization in societies, Proc. Natl. Acad. Sci. U.S.A. 122 (44) e2517530122, https://doi.org/10.1073/pnas.2517530122 (2025).