The integration of children with an immigrant background into education systems remains a key policy issue for many OECD countries. Immigrant children currently make up around one-fifth of pupils in OECD schools (OECD, 2025). However, on average, immigrant students are more likely to underperform academically, report a weaker sense of belonging at school, and experience higher levels of bullying than their native peers.
Language plays a key role in these disparities; only around half of 15-year-old immigrant pupils report speaking the language of the host country at home. These patterns suggest that integration involves more than just access to education; it also requires meaningful participation in it. This raises important questions about the mechanisms that facilitate or hinder the full inclusion of immigrant children in school environments.
Using data from the Programme for International Student Assessment (PISA) covering 16 OECD countries, our research shows that proficiency in the host country's language has a substantial causal impact on immigrant students’ integration at school. By exploiting variation in age at arrival and linguistic distance between the languages of origin and destination, we have isolated the effect of language acquisition from underlying socio-economic characteristics.
Our results indicate that language proficiency is a key factor in shaping both academic and social outcomes. Reducing the reading gap between immigrant and native pupils by 10% would eliminate approximately one in ten of the difference in school integration between the two groups. Language proficiency also improves achievement in mathematics and science, and reduces the likelihood of grade repetition.
Proficiency in the host country's language plays a pivotal role in shaping not only immigrant children's academic performance, but also their emotional well-being and social integration. Immigrant children who can communicate in the host country's language experience less bullying and victimisation, particularly among boys.
Importantly, the gains are not limited to immigrant students. Schools in which immigrant pupils have stronger language proficiency also exhibit improved academic and social outcomes among native pupils. This pattern is consistent with positive peer spillovers, suggesting that investments in language acquisition benefit the whole classroom rather than targeted groups alone.
Furthermore, the relationship between language proficiency and social inclusion is not confined to newly arrived immigrant pupils. Among second-generation immigrant pupils, who were born in the host country, stronger reading proficiency is also associated with greater school integration and significantly less exposure to bullying.
Language matters because it shapes everyday interaction. Pupils who can communicate effectively are better able to participate in lessons, form friendships, navigate social norms. Limited proficiency can heighten isolation and vulnerability to victimisation, which undermines well-being and educational engagement. Over time, these social and emotional aspects of schooling can perpetuate academic inequalities and impact long-term labour market integration.
For policymakers, the implications are clear. Language support should not be viewed solely as a short-term or remedial intervention for newly arrived students. Instead, sustained investment in host-country language proficiency should be viewed as a foundational component of integration policy. As Europe struggles to integrate children and young people with an immigrant background, investing in language training is essential for strengthening social integration.
References:
Qin, Yu, Vlassopoulos, Michael and Wahba, Jackline (2026). Host Country Language and School Integration of Immigrant Students Rockwool Foundation Berlin, Discussion Paper Series 048/26.
OECD (2025) Migration Data in Brief, no 15, June 2025.