How Do Vegetarians Make Pro-Environmental Decisions Unrelated to Food Choice? A MouselabWEB Study

Adopting a vegetarian diet represents a meaningful daily contribution to climate change mitigation. This makes vegetarians a relevant group for studying the cognitive mechanisms underlying pro-environmental decision-making. In this study, vegetarians and non-vegetarians completed a decision-making task involving real trade-offs between financial rewards and carbon emissions, with information acquisition tracked using MouselabWEB. We found that vegetarians exhibited a greater propensity to select the pro-environmental option than non-vegetarians. This group difference was particularly found when decisions entailed high personal costs, low environmental benefits, or uncertain outcomes. Process-tracing data further revealed that vegetarians consistently prioritized environmental information, and this attentional focus significantly predicted pro-environmental choices. Decision-level and process-tracing effects were attenuated when controlling for environmental attitudes, highlighting the role of vegetarians’ strong environmental commitment. Overall, the findings suggest that vegetarians may rely on a principled decision-making style that transcends cost–benefit considerations, offering new insights into the cognitive basis of pro-environmental engagement.