Theory-of-mind development in educational bilingualism: Identifying the strongest predictors of performance and tracking them over time.

This longitudinal study monitored Theory-of-Mind development in monolingually-raised but bilingually-educated Spanish children (age 5-6) with varied L2-English curricula (13-83%) to assess whether higher L2-exposure resulted in advantages on seven ToM concepts (emotion, desires, belief, reference, moral-reasoning, lies, sarcasm). Attention (selective, switching, inhibition) and a full suite of individual-difference effects were also monitored. GLMMs linked greater L2-exposure to higher ToM accuracy, and although all three attention measures contributed to ToM scores, the effect of selective-attention was the strongest. L1-vocabulary and NVR routinely predicted ToM scores, and girls surpassed boys on Sarcasm. We conclude that bilingualism spurs ToM development quickly and is not linked to L2-vocabulary at this stage. In addition, the fact that L2-exposure and individual differences impacted cognitive, affective and conative ToM differentially supports an approach that analyses these components separately.