Significance Cooperation is key to well-functioning groups and societies. Rather than addressing high-cost cooperation involving giving money or time and effort, we examine social mindfulness—a form of interpersonal benevolence that requires basic perspective-taking and is aimed at leaving choice for others. Do societies differ in social mindfulness, and if so, does it matter? Here, we find not only considerable variation across 31 nations and regions but also an association between social mindfulness and countries’ performance on environmental protection. We conclude that something as small and concrete as interpersonal benevolence can be entwined with current and future issues of global importance.