In today's world where growth and capital accumulation are the norm, many people still adhere to zero-sum thinking, the belief that gains for one party can only come at the expense of another party. The perception of economic exchange as zero-sum can lead to excessive competition and uncooperative behavior. We investigate social mobility as a driver of zero-sum beliefs by leveraging worldwide survey data and recently published data on intergenerational educational mobility. We find that a higher probability of experienced downward mobility in an individual's cohort and education group is associated with increased zero-sum beliefs. Consistent with gender-specific status concerns, experienced downward mobility only strengthens zero-sum beliefs for men.