An Examination of the Relationship Between Parent and Child Pragmatic Language in ASD Families Using HLM

Background: Impairments in social or pragmatic aspects of language are hallmark features of ASD and differentiate individuals with ASD from those with other developmental disorders.  Parents of children with ASD demonstrate more social communication difficulties than parents of children without ASD.  This well-replicated phenomenon has been deemed the broader autism phenotype. However, relations between parent and proband’s use of pragmatic language within the same family has yet to be examined.

Objectives: We analyzed the relationship between ASD parents’ use of pragmatic language and the degree of pragmatic language impairment in their children.  Various aspects of pragmatic language were assessed, including conversational skills, intonation patterns, gestures, and interest in social language.  Clinician-rated as well as self-rated measures were analyzed for both parents and children.  Relationships between Verbal IQ and pragmatic language were also assessed.

Methods: The sample consisted of 345 nuclear families containing at least two children with ASD.  Data were available from 341 mothers, 294 fathers, 993 probands (n = 789 males and n = 204 females), and 128 unaffected siblings (n = 63 males and n = 65 females).  All probands met criteria for an ASD according to ADI-R, ADOS, and clinical diagnosis.  Pragmatic language in parents was obtained via items from the Broader Phenotype Autism Symptom Scale (BPASS; semi-structured clinical interview and observation), Social Competence Questionnaire (ComQ; self-report), and Family History Interview (FHI; semi-structured clinical interview).  Pragmatic language in children was assessed using items from the ADOS (clinician observation), ADI-R (semi-structured clinical interview), ComQ (parent-report), and BPASS.  Verbal IQ was measured in all participants with age appropriate Wechsler scales of intelligence.

Results: Random coefficient multilevel modeling was used to account for the nesting of individuals within family in the estimation of standard errors and parameter estimates.  Specifically, random coefficient hierarchical linear models (HLM) were constructed to examine the relation between parent and child levels of pragmatic language in the variables of interest.  All available data were used based on empirical Bayes estimation in HLM.  Limited results are presented in this abstract.  On the ComQ, mothers’ likelihood of initiating a conversation with someone new significantly predicted child’s likelihood of initiating a conversation, t(261) = 2.15, p =  0.033.  Additionally, maternal Verbal IQ was significantly predictive of child’s likelihood to maintain a conversation on the ComQ, t(244) = 2.13, p = 0.034.  Both mother and father Verbal IQ predicted child Verbal IQ, p < .001 and p < .01, respectively.  However, in general, father’s self-reported conversation skills and Verbal IQ were not predictive of child pragmatic language abilities. 

Conclusions: Maternal pragmatic language abilities significantly predicted child level of pragmatic language level.  Specifically, mothers with stronger pragmatic language skills had children with higher levels of pragmatic language.  This same pattern was not found in fathers despite a strong relationship between father Verbal IQ and child Verbal IQ.  These results support the possibility of a maternal transmission pattern in pragmatic language abilities in ASD.