School Diversity and Social Capital: Conditions That Foster Bridging Ties in Schools

Diverse social networks can drive upward mobility for low-income youth, yet ties across social class remain difficult to form due to structural and organizational constraints. We examined the mechanisms through which friendship ties form within schools, especially cross-class ties. Using administrative and survey data from 948 11th-grade students, and 32 student interviews, across five high schools in metropolitan Detroit, we found that shared extracurricular activities and courses are the strongest predictors of friendships, while residential proximity plays a minimal role in most schools. We found that these mechanisms operated similarly for cross-class and same-class friendships, suggesting that students do not require different social processes to bridge class differences. Rather, it is the unequal opportunity for repeated interaction within organizational settings that prevents cross-class friendships from forming. Interviews further illuminated mechanisms through which school activities created spaces for cross-class interaction. Findings suggest schools can foster cross-class and other social ties through intentional programming, course structuring, and course scheduling, with important implications for educational equity and social mobility.