Supplementary materials to “Selective exposure and the authoritarian dynamic: Evidence from Canada and the United States”

This study explores to what extent selective exposure to political messages can produce political (in)tolerance among authoritarians and non-authoritarians. Drawing on a selection-exposure experiment embedded within an online survey conducted in the United States (N = 1978) and Canada (N = 1673), we explore how authoritarians and non-authoritarians react to framing around civil liberties controversies. Participants were randomly assigned to receive a message about a controversial group. In the forced-choice condition, participants were randomly assigned a political or non-political message. In a second condition, participants were given a choice of which message to read more about. The results show that authoritarians who are politically knowledgeable generally avoid messages that promote free speech by consuming non-political information. While messages about the dangers of free speech have the potential to produce more intolerance among authoritarians, we found that this effect was limited to those who are the least likely to consume them when given a choice. By contrast, we found that messages about the risk posed by free speech produced intolerance among non-authoritarians for whom threat-related cognitions were already chronically accessible. The effects of pro-civil liberties messages were limited to unthreatened non-authoritarians. Hence, we conclude that in the contemporary information environment selective exposure can increase polarization around a civil liberties controversy by producing attitude change but this occurs mainly among non-authoritarians.