Women have long surpassed men in the arena of environmental action; across age groups and countries, females tend to live a more eco-friendly lifestyle. Compared to men, women litter less, recycle more, and leave a smaller carbon footprint. Some researchers have suggested that personality differences, such as women’s prioritization of altruism, may help to explain this gender gap in green behavior.

Our own research suggests an additional possibility: men may shun eco-friendly behavior because of what it conveys about their masculinity. It’s not that men don’t care about the environment. But they also tend to want to feel macho, and they worry that eco-friendly behaviors might brand them as feminine.