Syntactic development in children with intellectual disabilities - using structured assessment of syntax

Area of Science:

• Developmental Psychology
• Linguistics
• Neurodevelopmental Disorders

Background:

• Children with intellectual disabilities (ID) exhibit significant delays in syntactic development compared to other language skills.
• Investigating the specific conditions influencing syntactic development in Japanese children with ID is crucial.

Purpose of the Study:

• To examine the syntactic development in native Japanese-speaking children with intellectual disabilities.
• To compare syntactic abilities between children with ID and typically developing children of the same mental age.

Main Methods:

• A comparative study involving 51 children with ID (including autism spectrum disorders and Down syndrome) and 78 typically developing children.
• Assessment of spoken language syntax through receptive and production tasks, matched for mental age.

Main Results:

• Children with ID demonstrated significantly delayed syntax development compared to typically developing peers with equivalent mental age.
• A notable acceleration in syntax development was observed once children with ID reached a mental age of 7-9 years.
• Children with autism spectrum disorders struggled with passive voice acquisition, while Down syndrome presented with broader syntactic delays.

Conclusions:

• Mental age and the specific type of intellectual disability significantly impact syntactic development.
• Achieving a mental age exceeding 7-9 years is a key factor for substantial progress in syntax abilities among children with ID.