IQ Profiles in Bilingual Children With Developmental Language Disorder: The Role of Maternal Education

The intellectual profile of monolingual children with Developmental Language Disorder is typically characterized by below-average verbal IQ (VIQ) and average Performance IQ (hence, PIQ) scores. Our knowledge of IQ functioning in bilingual children with Developmental Language Disorder is still very limited. Furthermore, previous research in IQ functioning in children with Developmental Language Disorder has not addressed maternal education as a possible alternative exploratory variable affecting children's performance in IQ tests. Here, we aimed to investigate if intellectual functioning of children with Developmental Language Disorder is affected by bilingualism, and whether this relation is affected by the children's socioeconomic characteristics, including maternal and parental education, and family income.

We focused on IQ profile comparisons between 125 bilingual children and 109 monolingual children with Developmental Language Disorder.

We found that the bilingual children exhibited 'normalized' performance in those VIQ tests that tapped into metalinguistic knowledge and social understanding. The bilingual children were also more likely to exhibit average skills across PIQ tests. Finally, we found that the positive effect of bilingualism on children's IQ was only observed for the children whose mothers had a low educational level.

The overall findings hold implications for the broader understanding of intellectual functioning in bilingual neurodiverse populations, also highlighting the unique role of maternal education in studying children's cognitive development.