Migration and mobility increase the cultural diversity of a society. Does this diversity have consequences for how people interact and form social ties, even when they join a new community? We hypothesized that people from regions with greater cultural diversity would forge more diversified social ties in a newly formed community, connecting otherwise unconnected groups. In other words, they would become social brokers. We tested this prediction by characterizing the social networks of eight Master of Business Administration cohorts (N = 2,257) at a business school in the U.S. International students (N = 773) from populations with both greater present day ethnic diversity and a history of extensive cultural intermingling were more likely to become social brokers than international students from less diverse nations. Domestic students' (N = 1,461) brokerage scores were also positively related to the ancestral diversity of the U.S. county they identified as "home." The results of this study suggest that more culturally diverse social environments-defined here at multiple geographic and temporal scales-endow people with socially adaptable behaviors that help them connect broadly within new, heterogeneous communities. (PsycInfo Database Record (c) 2022 APA, all rights reserved).