We study if there is an association between culture on gender roles and the gender gap in choice of major. For this purpose, we use the epidemiological approach and sibling comparisons. We find that the gender gap in STEM is smaller for individuals who originate in countries where women are more likely, relative to men, to major in STEM. We observe a similar pattern when we study the probability to major in a male- or female-dominated field. We present suggestive evidence that cultural beliefs explain our results. Thus, to limit gender segregation in education this study points to the importance of changing gendered beliefs about educational choices. However, the results indicate that the gender convergence in STEM and male-dominated fields is driven by the fact that men, not women, choose less gender-typical majors. This suggests that to increase women’s participation in STEM and male-dominated fields, policies in other areas, e.g., directed towards changing workplace characteristics, may also be necessary.