Aims and Objectives: While research has focused on effects of language exposure within the family, evidence for the role of the quality and quantity of language exposure within peer contexts for the acquisition of both majority language (ML) and heritage language (HL) skills is still limited. Against this background, the present contribution investigates the patterns in which language exposure within family and peer contexts relate to different bilingual reading outcomes of migrant adolescents. Design: The data used for this contribution provide a unique opportunity to fill in this research gap as it contains standardized reading assessments in the ML and HL as well as questionnaires on language exposure within peer and family contexts. Data and Analysis: Using multinomial regression models with a sample of n = 803 adolescents with German–Russian and German–Turkish language backgrounds, we investigate the role of adolescents’ bests friends’ language backgrounds and language skills as well as adolescents’ language use with parents for the prediction of different bilingual reading outcomes (i.e., skilled bilingual readers, skilled ML readers, skilled HL readers, and low-skilled bilingual readers). Findings: The results indicate that dual inclusion into best friendships with both monolingual German as well as HL peers might be a favorable friendship pattern as it is positively related to both the skilled bilingual reading and the skilled ML reading outcome. Furthermore, we observe a tendency that skilled bilingual readers benefit from having a high-skilled HL speaking best friend. In addition, HL use with parents is an important predictor for HL skills, but not a hindrance for high ML proficiency. Effects of the peer group predictors are rather small, nevertheless they add value for explaining bilingual language outcomes controlling for relevant predictors.
