Majority Rules? The Effects of School Ethnic Composition on Substance Use by Mexican Heritage Adolescents.

This article examines key aspects of the school environment - its composition by ethnicity and acculturation - as important social contexts for understanding Mexican immigrant and Mexican American adolescents' drug use norms and behaviors. Results are presented based on surveys completed by Mexican-background students from 35 Phoenix. Arizona middle schools, whose enrollment ranged from a numerical minority to an overwhelming majority. Multivariate mixed models tested for the influence of school ethnic composition measures on substance use outcomes, while accounting for individual level predictors and for the nesting of data at the school level. The proportional representation of Latinos in the school was not a factor in an individual's drug use norms or drug use for the sample overall. Once students were broken down by acculturation status, however, ethnic composition had an effect. Less acculturated Mexican heritage students in schools with higher proportions of Latino students reported less substance use and less adherence to pro-drug norms. Further investigation using other measures of ethnic composition suggested that these effects were attributable to the larger presence of less acculturated Latinos in the school rather than more acculturated Latino students. These school-level effects support the individual-level results indicating that less acculturated Mexican American students face less daunting substance use risks. The results suggest that ethnic group size, but not necessarily numerical predominance, matters and that within-group differences influence the effect of a particular ethnic group's presence in the school. In other words, the majority does not always rule. These findings are interpreted using the concepts of segmented assimilation and school level social capital.