What contributes to gender-associated differences in preferences such as the willingness to take risks, patience, altruism, positive and negative reciprocity, and trust? Falk and Hermle studied 80,000 individuals in 76 countries who participated in a Global Preference Survey and compared the data with country-level variables such as gross domestic product and indices of gender inequality. They observed that the more that women have equal opportunities, the more they differ from men in their preferences. Science , this issue p. [eaas9899][1] ### INTRODUCTION Understanding determinants of gender differences in economic and social domains has been of interest, both in academic and public debates. Previous research has shown that gender differences in fundamental economic preferences are important in explaining gender differences in economic outcomes, such as for occupational choice, financial investment, or educational decisions, among many others. However, gaps remain in understanding the sources of gender differences…