Language performance in siblings of nonverbal children with autism.
Language scores in siblings of non-verbal children with autism normalize once IQ is accounted for, suggesting language is not part of the Broad Autism Phenotype.
01Research in Context
What this study did
Levy et al. (2011) compared language skills in two groups of kids. One group had brothers or sisters who were non-verbal and had autism. The other group had no family history of autism.
All kids took IQ tests and language tests. The team also listened to how each child spoke during free play. They wanted to see if siblings of non-verbal kids scored lower even when IQ was the same.
What they found
Once IQ was matched, the language scores of both groups were the same. Grammar used during play was also equal.
In short, having a non-verbal sibling with autism did not hurt language when IQ was held steady.
How this fits with other research
Yirmiya et al. (2007) looked at younger toddlers and saw language delays in ASD siblings. The new study shows these delays fade by school age once IQ is counted.
Garrido et al. (2017) pooled many studies and still found medium language gaps in infants. The gap shrinks as kids grow, matching the present result.
Chuthapisith et al. (2007) found lower verbal scores only when the autistic child also had intellectual disability. Yonata’s team confirms this fine point.
Why it matters
You can reassure parents that school-age siblings of non-verbal children with autism are unlikely to have lasting language problems if their IQ is typical. When you see low scores, check IQ first before assuming a language disorder. This saves time and lowers worry.
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02At a glance
03Original abstract
The study focuses on language and cognitive abilities of siblings of the linguistically most affected children with autism (i.e. siblings of nonverbal children - SIBS-ANV). Twenty-eight SIBS-ANV (17 boys), ages 4-9 years, took part in the study. All children attended regular schools, and none had received a diagnosis of autism. Controls were 27 typically developing children (SIBS-TD; 16 boys) matched to the SIBS-ANV on age, family background, socioeconomic status and type of school they attended. Significant IQ differences, as well as language differences as measured on the Clinical Evaluation of Language Fundamentals (CELF), emerged between SIBS-ANV and SIBS-TD. However, differences in the language scores mostly disappeared when PIQ and FSIQ were controlled for. Furthermore, grammatical analysis of spontaneous speech samples produced in the course of testing did not reveal any significant differences between the groups. These results add to recent work suggesting that language deficits may not be part of the Broad Autism Phenotype (BAP). It further suggests that the cognitive deficit characteristic of nonverbal people with autism may be familial.
Autism : the international journal of research and practice, 2011 · doi:10.1177/1362361310386504