Antón, E. 1 , Thierry, G. 4, 5 , Carreiras, M. 1, 2, 3 & Duñabeitia, J. A. 1
1 BCBL, Basque center of Cognition, Brain and Language, Donostia, Spain.
2 Ikerbasque, Basque foundation for Science, Bilbao, Spain
3 University of the Basque Country EHU/UPV, Bilbao, Spain
4 School of Psychology, Bangor University, Adeilad Brigantia, Bangor, Gwynedd LL57 2AS, UK
5 Economic and Social Research Council Centre for Research on Bilingualism in Theory and Practice, Bangor University, Bangor, UK
Traditionally, formal education in bilingual societies has followed the one-subject-one-language motto, assuming that only one language should be used during the tuition of a given academic subject to prevent for any possible difficulty associated from an incorrect conceptual representation as a consequence of mixing languages. The current study was aimed at investigating whether the use of two vehicular languages as compared to a single one harms the integration of new concepts, or alternatively, whether an educational model based on the regular mixing of two languages during instruction should be favored. Spanish-Basque bilingual children and adults were tested in a series of experiments in which they had to learn some novel concepts represented by unknown objects associated to definitions of existing and known objects of daily life. Half of the subjects completed the learning phase in a single-language context, while the other completed it in a dual-language context. Several indirect and direct measurements of learning, conceptual representation and integration were collected. Results from both adults and children showed that language-mixing contexts were not detrimental for the learning process. These data showed no significant differences between groups, yielding the conclusion that mixing languages provides learners with enhanced communicative skills in the full absence of any detriment in concept acquisition.