Abstract

Scholars posit that childhood exposure to ethnic outgroups may durably improve intergroup relations. To date, however, few studies are able to track the consequences of childhood experiences across multiple decades. Moreover, existing research focuses overwhelming on majority populations and largely overlooks the impact of exposure for minority groups. Using linked geocoded US census records from 1880 to 1900/1910, we analyze the relationship between childhood exposure to neighbors of a different ethnicity and subsequent marriage patterns for over 400,000 American, German and Irish men. To account for residential self-selection, we apply a machine-learning algorithm to identify historic ``ethnic" neighborhoods and compare individuals with similar sociodemographic and neighborhood characteristics, but who differ in the identity of their next-door neighbors. We find that exposure to an ethnic outgroup in 1880 is consistently associated with a higher likelihood of marriage to a member of that group in later life, as well as a lower likelihood of ingroup marriage. Overall, these findings underscore the potential for childhood experiences to erode ethnic group boundaries.