The influence of language on exact additions in bilinguals.

To which degree is language involved in arithmetic and dependent on language proficiency? We investigated this question in a German-French educational bilingual setting in Luxembourg, where there is a progressive transition from German to French as a teaching language. Due to this shift, students become increasingly more proficient in the non-dominant language (French) throughout the school years. Interestingly, the decades and units of two-digit number names follow the unit-decade order in German but the decade-unit order in French.

Students from grades 7, 8, 10, 11, and German-French adults (total N = 200) solved simple and complex additions presented in different conditions: (1) visual Arabic digits, (2) auditory presentation, and (3) as a dual task in which visually presented additions were preceded by visually presented semantic judgements to indirectly activate a language context. Participants performed each condition in a German and a French testing session. Participants were asked to respond orally in the testing language. Measures include correct responses and response times.

The results suggest that language proficiency is crucial for the computation of complex additions, whereas simple additions can be retrieved equally well in both languages. Furthermore, additional error analyses showed more errors on the decade or on the unit digit depending on the language of the task. However, providing a language context seems to enhance performances only in the non-dominant language. Taken together, these results support the view of a strong language influence on arithmetic.