Different norms, different impacts? Testing the effects of deliberative norms on climate deliberation

The need to find rapid yet fair and legitimate policy responses to climate change has prompted calls for more democratic deliberation in climate policymaking. Democratic deliberation, however, contains varying normative goals, which may have diverse effects on participants of climate deliberation. We distinguish three types of deliberation: ‘Habermasian’ deliberation emphasizing the quality of justification, integrative deliberation emphasizing mutual understanding, and inclusive deliberation emphasizing consideration of affected interests. To analyze the impacts of these types, we conducted a population-based, randomized lab-in-the-field experiment, where three treatment groups deliberated Finland’s climate policies face-to-face online. We induced the deliberation types through different discussion norms and exercises taken in the beginning of deliberation. We report the treatments’ impacts on participants’ climate knowledge, policy attitudes and affective polarization. Overall, we find little support for our hypotheses, and some findings actually go against our expectations. The unexpected findings can be partly explained by group composition and resulting enclave deliberation. In addition, short deliberation time may have contributed to the modesty of the effects. Our results both confirm earlier findings on the impact of deliberation on participants and highlight the importance of opinion diversity in climate deliberation.