Persistent beliefs: Political extremism predicts ideological stability over time

Previous research suggests that political extremists have stronger convictions in their beliefs than moderates. The present research examines the relationship between political extremism and belief stability, defined as the extent to which people change their ideological beliefs over time. Studies 1 (N = 397) and 2 (N = 291) revealed that participants at the left and right extremes report more stable beliefs than political moderates. We then reanalyzed a longitudinal study that tracked actual ideological changes over time during a referendum (Study 3, N = 5812). Results indicated that for ideological orientation measured at three time points, politically extreme respondents had lower standard deviations—and hence, more stable ideologies over time—than moderates. Furthermore, the effect appeared more pronounced among people at the left than people at the right. We discuss implications of these insights for political extremism in society and the malleability of political ideology.