Journal article: We show in a large-scale field experiment that a brief exposure to female role models working in scientific fields affects high school students’ perceptions and choice of undergraduate major. The classroom interventions reduced the prevalence of stereotypical views on jobs in science and gender differences in abilities. They also made high-achieving girls in Grade 12 more likely to enrol in selective and male-dominated STEM programs in college. Comparing treatment effects across the 56 role model participants, we find that the most effective interventions are those that improved students’ perceptions of STEM careers without overemphasizing women’s under-representation in science.