Cognitive Skills in Bilingual and Monolingual Children with Low and High Levels of Autistic-like Traits

Background: Research on bilingualism has shown cognitive advantages, such as in executive functions (e.g., attentional control; Adesope et al., 2010) and Theory of Mind (i.e., belief attribution to oneself and others; Nguyen & Astington, 2014). Alternatively, the same areas are often impaired in autism (Baron-Cohen, 1991; Schuh & Eigisti, 2012). Therefore, studying bilingualism and autism offers an avenue for investigating interactions between contrasting cognitive profiles. However, diagnosing autism may be more complex and qualitatively different in bilinguals than in monolinguals. Specifically, the same levels of autistic traits tend to be acknowledged to a significantly different degree across various cultures (Burke et al., 2015). As bilinguals are often bicultural, investigating potential interactions of bilingualism and autism only in diagnosed samples suffers a risk of leaving out a large part of the spectrum caused by a possible cultural bias in the diagnosis.

Objectives: The study investigates the interaction of bilingualism and autistic-like traits (ALTs) in a general sample of children in relation to their cognitive skills. By looking at children with low or high levels of ALTs from a general population sample, without requiring a clinical diagnosis of autism, we eschew any disparities that might arise between monolinguals and bilinguals caused by the diagnostic bias. The following questions are addressed: (1) do bilinguals and monolinguals differ in their executive function and Theory of Mind skills? (2) does the level of ALTs affect children’s executive function and Theory of Mind skills? (3) does bilingualism have any ameliorating effects on cognitive skills in children with high ALTs?

Methods: The sample included 19 bilinguals with high ALTs, 25 bilinguals with low ALTs, 21 monolinguals with high ALTs, and 28 monolinguals with low ALTs, matched on age (M = 9;1, SD = 1;7) and the socioeconomic status. Monolinguals spoke English, and bilinguals spoke English and another language. Low ALTs indicated virtually no impairment in social communication/interaction and in restricted interests/repetitive behaviour (≥ -1SD from the population mean on the ALTs measure). High ALTs indicated difficulties in the same areas (≥ +1SD from the population mean on the ALTs measure). ALTs were measured with the Social Skills Improvement System-Rating Scales (Gresham & Elliott, 2008) and the Social Communication Questionnaire (Rutter et al., 2003). Demographics were collected through a caregivers’ questionnaire. The dependent variables were measured with three executive function tasks and a Theory of Mind task.

Results: On the executive function tasks, bilinguals and monolinguals performed equally well. However, children with low ALTs performed significantly better than children with high ALTs. On the Theory of Mind task, bilinguals showed more accurate responses than monolinguals. Similarly, children with low ALTs were more accurate than children with high ALTs. Finally, the initial analyses showed some ameliorating effects of bilingualism in children with high ALTs based on their Theory of Mind accuracy scores.

Conclusions: The study identifies traces of positive effects of bilingualism on some aspects of cognition in children with high ALTs. Further investigations are required in larger samples including children with even higher levels of ALTs.