Should Students Be Taught in Their Mother Tongue? Evidence from Catalonia

Álvaro Choi

Evaluating the effects of specific country / regional policies using large scale international assessments is a challenging task. This is primarily because this is not actually what they have been designed for. However, the rich data contained within the PISA background questionnaires can sometimes provide important clues for the direction that education policy should take. One such example from my home country is the Linguistic Immersion Policy (LIP) which has been operating in Catalonia since 1992.

The Linguistic Immersion Policy

In many countries there is debate about whether minority students should be taught in the official language or in their minority language. However, as far as I know, linguistic immersion policies in Europe are only in applied Greenland, the Faroe Islands and Catalonia.

The main objective of this programme is to help students master a language other than their mother tongue. Immersion programmes differ from bilingual programmes in the intensity of students’ exposure to this language while at school. Catalonia’s LIP was implemented in a Spanish-Catalan bilingual society with the aim of promoting the use of Catalan. Spanish and Catalan are co-official in Catalonia. The Catalan LIP established that, during the ten years of compulsory education, teachers should teach all contents in Catalan. The view amongst the Catalan authorities was that students in Catalonia will “naturally” master Spanish via non-academic means (family, friends, TV, films, radio, books etc).

The application of this policy has been controversial, with most arguments for or against it being mainly ideological. Those who defend the LIP stress the need to invigorate the use of Catalan after years of prohibition and argue that achieving bilingualism has cognitive benefits. Studies have also suggested that knowing Catalan has positive returns in the labour market. Advocates of the LIP also assert that it guarantees the perfect command of both languages by the end of compulsory education and that the skills of Catalan students in Spanish are similar to that of (Spanish-speaking) monolingual regions.

Those who argue that the LIP should be retracted often argue that the sociopolitical conditions in Catalonia are very different now to previously and that parents should have the right to choose the language of instruction for their children. They are also concerned about the possible negative effects on academic performance of learning a language different to their mother-tongue, while also highlighting the lack of robust evaluations of the Spanish skills of Catalan students compared to students from the rest of Spain. Indeed, there is very little evidence on the effects of the LIP on the academic performance of students in general.

Assessing the LIP using PISA

Therefore, in a recent study with Jorge Calero, we use PISA to identify whether being taught in Catalan had different effects on the skills of 15-years-old students depending upon their mother tongue. PISA allowed us to perform this analysis because a) students participating in PISA 2015 were born in 2000, well after the policy was implemented (1992); b) Catalonia has a regionally representative sample in PISA; c) PISA in Catalonia is assessed in Catalan; d) all students in public and private-publicly funded schools are taught in Catalan; and e) the background questionnaire provides information on the language spoken at home.

Winners and losers

Our results suggest that, after controlling for background and school characteristics, Catalan-speaking students outperform Spanish-speaking students in reading and science, while there was no difference in mathematics (Figure 1). We also found that the negative effect of the policy was larger for males and for those studying in public schools.

All in all, our study uncovered that, while bilingualism is generally an asset, the LIP generates winners and losers. As expected, the publication of the report met extreme reactions by the Spanish conservative and Catalan nationalist media, think tanks and political parties. Explaining the political use of PISA in Spain is worthy of another blog post in itself.

Álvaro Choi is Associate Professor at the University of Barcelona