This meta-analysis explores how Normative Conduct Theory explains high-involvement behaviours, such as choosing electric vehicles, and low-involvement behaviours, such as reducing meat intake – both aimed at lowering carbon emissions. The study reveals that personal norms, descriptive norms, injunctive norms and social norms positively correlate with both behavioural categories examined. Personal norms are found to have the most significant impact on low-involvement behaviours, aligning with existing literature. In contrast, injunctive norms are the most influential for high-involvement behaviours, such as selecting electric vehicles, suggesting that these choices are strongly impacted by recommendations from significant others. Descriptive norms, social norms and personal norms follow in their influence on EV uptake. The analysis highlights the complex role of normative influences in promoting carbon reduction behaviours, providing valuable insights for advancing theoretical understanding and developing practical interventions to encourage sustainable choices.