Language, Theory of Mind, and Executive Function Skills in Deaf Children with Spoken Language Multilingualism

Increasing numbers of deaf children around the world use multiple spoken languages, with or without a signed language(s) as well. A complex relationship exists between language ability, executive function (EF), and Theory of Mind (ToM), and deaf children can be at risk of difficulties in all three areas of development. Research on language outcomes in children with spoken language multilingualism (SLM) is highly varied, and the development of EF and ToM in this population has not yet been explored. This study examined the language and cognitive (EF and ToM) abilities of five deaf children with SLM compared to five deaf oral monolingual children, five hearing multilingual children and five hearing monolingual children. The children were matched as closely as possible on demographic factors (including age, gender and parental education), as well as on their audiological profile for the deaf children (including age of diagnosis, type/degree of deafness and type of technology used). English language abilities in expressive vocabulary and morphosyntax were tested, and the multilingual deaf and hearing children’s home language(s) was also indirectly assessed using parental reports. Results showed that deaf children with SLM performed in the same range as the other three groups on both the measures of EF and ToM, and morphosyntactic abilities in English. Expressive vocabulary skills in English were lowest for the deaf children with SLM; however, three out of five children scored above average compared to monolingual test norms. Parental ratings of the children’s home language skills were also very similar for the multilingual deaf and hearing children. Deaf children with SLM can achieve linguistic competency in at least two spoken languages and develop EF and ToM abilities in line with their hearing peers. Professionals should therefore not discourage multilingual parents from raising their deaf child with multiple spoken languages.