Who is Afraid of Our Shared Future?

Concerns about societal disequilibrium (such as shifting dominant group majority) are increasingly central to debates on democratic backsliding, political polarization, and the destabilizing effects of communication technologies. Yet the mechanisms through which such concerns shape perceptions of future solidarity with fellow citizens remain insufficiently specified. Existing research points to several plausible pathways: perceptions of disequilibrium may intensify antagonistic attitudes and social distance toward out-groups; exacerbate negative emotions such as fear and anger; or erode support for pluralist principles and democratic norms. However, prior studies have largely relied on correlational comparative evidence or single-country experimental designs, limiting both causal leverage and cross-national generalizability. This paper directly tests these competing mechanisms by examining whether and how they generate concerns about a shared future with fellow citizens. Using embedded experimental data from three Western European countries, we assess the relative impact of affective, attitudinal, and cognitive responses to a disequilibrium online cue. The findings show that the cue operates primarily through the activation of negative affect, rather than through shifts in social attitudes or democratic cognitions. Moreover, responses are politically heterogeneous: contrary to expectations, extremists are not consistently the most pessimistic about a shared democratic future. While extremism predicts pessimism in some national contexts, in others it is political moderates who express greater concern about future democratic solidarity. This puzzle challenges accounts of democratic backsliding and polarization that treat moderation as a stable reservoir of democratic commitment, and suggests that perceived disequilibrium may unsettle the political center as much as--if not more than--the extremes, depending on national context.