Forecasting collective trends in human opinion

We investigate how extreme opinion trends arise in society by analyzing 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 sharp statistical predictor for the rise of extreme views in society.
The precursor is a nonlinear relation between the fraction of individuals holding a certain extreme view and the fraction of individuals that includes also the moderates, e.g., in politics, those who are ``very conservative'' versus ``moderate to very conservative''.
By means of statistical physics modeling, we show that the onset of the nonlinearity allows to forecast the transition from moderate to extreme opinion before it actually occurs.
The tipping point is the result of an abrupt bootstrap-percolation transition with cascades of extreme views caused by the ``stubbornness" of individuals, as suggested by modeling.
By means of a phase diagram given in terms of critical fractions of extremists and number of people?s ties, we classify societies from moderate to extreme.
The nonlinearity is ubiquitous across a diversity of polls and countries and may reflect a remarkable ``generic" feature of human collective behavior at large.

Ref.: Ramos, M., Shao, J., Reis, S. D. S., Anteneodo, C., Andrade, J. S., Havlin, S., \& Makse, H. A. {\em How does public opinion become extreme?} Scientific Reports 5, 10032 (2015).