What voters think and feel about a climate law: cognitive–affective mental models during a Swiss national referendum

Lacking public support remains a major barrier to ambitious climate policy, yet little is known about how citizens mentally represent specific policy proposals and whether or how these representations change over time. We assessed voters’ cognitive– affective mental models of a real-world climate policy proposal, the 2023 Swiss Climate Protection Law, at two time points preceding a national referendum on the policy. A sample of Swiss voters (N=254) drew their mental models by adding their own cognitive associations and affective evaluations towards the law one month before and immediately prior to the referendum. Opposers were more likely to make reference to financial or personal costs and to rate concepts more negatively, whereas supporters were more likely to make reference to climate and future protection concepts and to rate concepts more positively. While the cognitive associations differed across voter groups, the complexity of mental models, indicated by the number of provided concepts and their interconnectedness, did not. Both opposers and supporters reported more cost-related concepts at the second time point but there was no strong evidence of increased complexity or changes in affective evaluations over time. Crucially, affective evaluations were the strongest predictor of final policy support relative to cognitive associations. These results suggest that while political campaigns may shape the considerations citizens associate with a policy, policy support does not necessarily reflect differences in the complexity of these representations and may be more closely associated with their affective evaluation than with their cognitive content.