Ready to read in two languages? Testing the native language hypothesis and the majority language hypothesis in two-way immersion students

Abstract Two-way immersion combines native speakers of the majority language with native speakers of a minority language and provides instruction in both languages. It remains unclear whether students have better reading comprehension in their L1 (native language hypothesis) and/or whether all students, irrespective of their L1, have better reading comprehension in the majority than in the minority language (majority language hypothesis). In this study of all fourth-grade two-way immersion classes in Berlin (N = 939 students), reading tests from a large-scale international student achievement study were administered in German and nine partner languages. The results of multivariate regression analyses supported the native language hypothesis, with L1 speakers outperforming L2 speakers on the interindividual level for both languages. The data also confirmed the majority language hypothesis: two-way immersion students, irrespective of their L1, scored significantly higher in German than in the partner language on the intraindividual level.