Testing mediating pathways between school segregation and health: Evidence on peer prejudice and health behaviors

School racial segregation is increasingly recognized as a threat to US public health: rising segregation in recent decades has been linked to a range of poor health outcomes for Black Americans. Key theorized mediators of these harms remain underexamined, including experiences of interpersonal and institutional racism driving increased stress, and peers' health behaviors influencing students' own. Using cross-sectional survey data on a national sample of adolescents, we investigated associations between school segregation and these two potential mediating pathways, operationalized as adolescents' perceptions of prejudice from fellow students and the health behaviors of their peers (drinking and smoking). We further investigated whether associations were modified by individual race/ethnicity and school racial composition. Pooling across all schools and students, higher levels of school segregation were associated with decreased perceptions of peer prejudice (OR 0.54, 95% CI = 0.34-0.86), but not with peers' health behaviors. However, this masked important differences by respondents' race/ethnicity and school racial/ethnic composition. In predominantly White schools, school segregation was not associated with Black students' perceptions of peers' prejudice, but higher levels of segregation were associated with increased rates of peers' drinking and smoking. In predominantly non-White schools, in contrast-where most Black students are educated-higher levels of school segregation were not associated with perceived peer prejudice nor unhealthier peer behaviors for Black students (in fact, peers' health behaviors improved). And across both school types, higher levels of district segregation were associated with lower odds of reporting peer prejudice among non-Black students of color. Our findings suggest that the paths between school segregation and poor health depend on the type of school children attend in segregated districts. In schools predominantly serving students of color, structural factors upheld by school segregation-i.e., material, educational, disciplinary, or economic disadvantage-likely dominate over peer behaviors as the primary drivers of segregation's health harms.