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.