This article explores how language policy affects the socioeconomic development of nation states through two channels: the individual’s exposure to and (in reference to an individual’s mother tongue) linguistic distance from the official language. In a cross-country framework the article first establishes a robust and sizeable negative relationship between an official language that is distant from the local indigenous languages and proxies for human capital and health. To establish this relationship as causal, we instrument language choice with a measure of geographic distance from the origins of writing. Next, using individual level data from India and a set of 11 African countries, we provide microempirical support on the two channels—distance from and exposure to the official language—and their implications for educational, health, occupational and wealth outcomes. Finally, we suggest policy implications based on our findings.