Preferences over well-being of other generations shape family life, economic interactions, and political outcomes. This paper documents systematic, preference-based discrimination against young adults, and shows that it is partly due to an inaccurate belief that young adults face relatively little hardship, as compared to other generations. Using controlled experimental tasks implemented among a nationally representative sample in the Czech Republic, we find that people allocate substantially less money to individuals who are relatively younger, as compared to their own age group or relatively older age groups. The observed discriminatory behavior against the young adults is widespread, particularly severe among seniors, and similar in size to discrimination against immigrants and foreigners. On the constructive side, we show that this inter-generational divide can be reduced by a low-cost intervention. Most people underestimate the prevalence of mental health problems among young adults, and exogenous provision of accurate information increases prosocial behavior toward this group.