Navigating Nested Social Dilemmas: The Impact of Social Norms on Pro-Environmental Behaviour

As ecological crises intensify, promoting pro-environmental behaviour (PEB) has become increasingly urgent yet challenging, as individuals often prioritise self-interest over environmental considerations. While prior research confirms the influence of social norms on PEB, the differential effects of these norms (descriptive vs. injunctive) in contexts of conflicting personal, collective, and environmental interests remain insufficiently explored. This study utilised the Greater Good Game paradigm to simulate nested social dilemmas. Experiment 1 demonstrated that exposure to social norms substantially increased environmental choice. Experiment 2 indicated that descriptive norms outperformed injunctive norms, as evidenced by higher contributions to ecological sustainability. The overall findings suggest that PEB significantly increases under the influence of social norms, while self-interested behaviour diminishes, and cooperative behaviour remains consistent. Furthermore, the results revealed that descriptive norms are more effective in promoting PEB in complex, ecologically valid settings, as they can reduce behavioural uncertainty through social identity. This study incorporates normative cues within decision-making contexts involving competing interests and provides evidence-based guidelines for fostering sustainable behaviour.