Vocabulary characteristics of children with high and low functioning autism and intellectual disabilities

Objectives: Children with autism spectrum disorders (ASD) shows atypicality in various domains in language. One of atypical characteristics in their language can be found in vocabulary. Usually children show greater receptive than expressive vocabularies, but for ASD children the opposite results are reported. Even though children with autism show mutual exclusivity when mapping new words to the correct objects, their social deficits prohibit them from being reinforced by others' feedback. Thus they can have more difficulty in receiving initiation and directions from others, and as a result, can demonstrate atypical vocabulary characteristics. The purpose of this study is to find out the differences in expressive and receptive vocabulary abilities among children with high functioning ASD, low functioning ASD, and intellectual disabilities (ID), and the discrepancies in expressive and receptive vocabulary among the three groups. Methods: Ten high functioning ASD, 11 low functioning ASD, and 12 ID children were tested with the receptive and expressive vocabularies test (REVT). Results: The results indicate significant differences in receptive and expressive vocabularies. However, there was no significance between receptive and expressive vocabulary among three groups even though trends of higher expressive vocabularies over receptive can be found in the high and low functioning ASD group. Conclusion: The trends of higher expressive vocabulary in the two ASD groups compare to ID group tells high possibilities that children with ID can be reinforced by the feedback that the interaction partner gives. For the future studies, it is necessary to increase the sample size and add assessment tools which can prove vocabulary abilities.