How does public opinion become extreme?

TL;DR

This paper models how extreme opinions emerge in society, identifying early warning signals and classifying societal regimes through a physics-inspired approach based on opinion dynamics and percolation theory.

Contribution

It introduces a nonlinear activation model incorporating stubbornness, linking opinion extremism to a bootstrap-percolation transition and providing a framework to forecast societal shifts towards extremism.

Findings

Nonlinear relation precedes extreme opinion emergence.

Extreme views can cascade through society via percolation.

Societies can be classified by critical extremist fractions.

Abstract

We investigate the emergence of extreme opinion trends in society by employing statistical physics modeling and analysis on polls that inquire about a wide range of issues such as religion, economics, politics, abortion, extramarital sex, books, movies, and electoral vote. The surveys lay out a clear indicator of the rise of extreme views. The precursor is a nonlinear relation between the fraction of individuals holding a certain extreme view and the fraction of individuals that includes also moderates, e.g., in politics, those who are "very conservative" versus "moderate to very conservative" ones. We propose an activation model of opinion dynamics with interaction rules based on the existence of individual "stubbornness" that mimics empirical observations. According to our modeling, the onset of nonlinearity can be associated to an abrupt bootstrap-percolation transition with cascades of extreme views through society. Therefore, it represents an early-warning signal to forecast the transition from moderate to extreme views. Moreover, by means of a phase diagram we can classify societies according to the percolative regime they belong to, in terms of critical fractions of extremists and people's ties.