Popular beliefs that women are more caring or helpful than men misalign with mixed evidence about gender differences in prosociality, i.e., behaviour that benefits others. Nevertheless, can such beliefs, specifically about differences in altruism and generalized trust, lead to observed gender gaps in prosocial behaviours like volunteering? Using individual-level data on the volunteering of second-generation immigrants in the United States, I first document that men are 28% less likely than similar women to volunteer, but there are no obvious gender differences in volunteering hours. Linking these individuals to altruism and trust norms from their mothers’ countries of ancestry, I find that men’s volunteering is less influenced by norms about generalized trust compared to women, particularly along the extensive margin. My analysis suggests that this result is driven by a misperceived gender norm that places a greater responsibility on women to help others (particularly strangers), with tangible consequences for allocating unpaid labour.
