Language and communication skills in multilingual children on the autism spectrum: A systematic review

More than half the global population is estimated to be multilingual, yet research on autistic children who grow up in multilingual environments remains scant. We conducted a systematic review of peer-reviewed studies on multilingualism in autistic children and its impact on children's language and communication skills. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, our search identified 22 group comparison studies published from 2011 to 2022. The current review addressed two main questions: (a) Which language and communication skills of multilingual autistic children were assessed and how; and (b) how the skills of multilingual autistic children compared with their peers. Semantic-related skills were most frequently reported, while phonology and pragmatics were the most underreported dimensions of language. Most reviewed studies used a combination of direct and indirect language assessments. Available research provides no indication that being exposed to more than one language has adverse effects on the communication skills of autistic children. Although multilingual autistic children often have common autism characteristics, such as pragmatic difficulties affecting their communication skills, preliminary findings also indicate that they may share some advantages of multilingualism with their multilingual nonautistic peers. Studies often excluded participants with co-occurring diagnoses, which may have impacted the generalizability of the findings. Lay Abstract Both parents and service providers have voiced concerns about the potential negative impact of exposure to multiple languages on the language and communication skills of autistic children. The current literature review summarized research that assessed the language and communication skills of multilingual autistic children in comparison with their autistic and nonautistic peers. After a comprehensive search, 22 relevant publications were identified that met the inclusion criteria of the current review. Thirteen studies used both direct (directly administered screening/diagnostic tools) and indirect language assessments (e.g. parent questionnaires). Receptive and expressive vocabulary was the most frequently assessed language skill. Available research does not support the assumption that bilingualism has negative effects on the language and communication skills of autistic children. The language and communication skills of multilingual autistic children frequently resembled their monolingual autistic peers in both strengths and areas of growth. Preliminary findings indicate that multilingual autistic children may share some advantages of multilingualism with their multilingual nonautistic peers. Studies often excluded participants with intellectual disabilities or complex communication needs, which means that a large population of autistic children is not yet represented in research about the effects of multilingualism.