Conformity to social norm interventions is not amplified in tighter nations.

Social norms have a reliable and oftentimes strong influence on individual attitudes and behaviors across environmental and other domains. This influence has been theorized to differ by cultural tightness-the extent to which people adhere to shared cultural norms. Understanding whether and how cultural context moderates the influence of behavioral interventions is essential for the design of culturally-attuned and adaptable interventions to address collective action problems like climate change. Yet, past research has primarily relied on correlational approaches to demonstrate cross-cultural differences in norm adherence, without experimentally manipulating norm information across different settings, limiting insights into how cultural context shapes conformity to norm interventions. Our study tests the effects of three social norm interventions on the climate-related attitudes and behaviors of 16,089 participants in 42 countries. We find that conformity to social norm interventions is not uniformly amplified in tight cultures, suggesting a nuanced relationship between cultural tightness and normative interventions.