ABSTRACT
BACKGROUND: Children with autism spectrum disorder (ASD) show substantial variability in their language development. Language problems are highly prevalent in these children. In addition, the quality of early language abilities contributes to the overall development of these children and is highly predictive of their adult outcome. Yet, little is known about language development in children at risk of ASD during the first years of life. AIMS: To compare early receptive language (RL) and expressive language (EL) development in children at risk of ASD and determine predictors of language development. METHODS & PROCEDURES: Developmental trajectories of RL and EL were investigated from 10 to 36 months of age in younger siblings of typically developing children (LR-sibs, N = 30) and in younger siblings of children with ASD (HR-sibs, N = 31) using the Mullen Scales of Early Learning. Furthermore, both child and demographic characteristics were examined as possible predictors of language development. OUTCOMES & RESULTS: Both groups showed similar growth curves for RL and EL and the majority of the children showed average (within ±1.5 SD of the mean) or above-average language abilities. Nevertheless, the mean growth of EL was lower and the variation in growth of both RL and EL was higher in HR-sibs than in LR-sibs. Furthermore, early child characteristics were predictive of language development in both groups. Yet, some child characteristics seemed to be of more importance in HR-sibs than in LR-sibs. Consequently, lower non-verbal abilities at 10 months in both groups and a higher degree of ASD characteristics at 14 months in HR-sibs may be indicative of difficulties in language development. CONCLUSIONS & IMPLICATIONS: HR-sibs show more variation in their language development than LR-sibs during the first 3 years of life. The majority of HR-sibs, however, did not present with below-average language abilities. Yet, early characteristics of ASD may be a red flag for difficulties in the language development of HR-sibs.
Subject(s)
Autism Spectrum Disorder/complications , Child Language , Language Development Disorders/etiology , Language Development , Autism Spectrum Disorder/diagnosis , Autism Spectrum Disorder/genetics , Child Development/physiology , Early Diagnosis , Female , Genetic Predisposition to Disease , Humans , Infant , Language Development Disorders/diagnosis , Language Tests , Male , Siblings/psychology , Social ClassABSTRACT
This study compared sibling interactions between 24-month-old children and their older sibling with ASD (high-risk; n = 24) with 24-month-old children and their typically developing older sibling (low-risk; n = 32). First, high-risk sibling pairs showed lower levels of positive behaviour and younger siblings of children with ASD imitated their older sibling less. Second, in the high-risk group positive interactions were positively associated with the youngest child's language abilities. However, this association was no longer significant after controlling for language abilities at 14 months. Third, more total interactions in the high-risk group, both negative and positive, were associated with more ASD characteristics. Thus, early sibling interactions might reveal interesting information in light of the (atypical) developmental trajectories of younger siblings of children with ASD.
Subject(s)
Autism Spectrum Disorder/psychology , Communication , Sibling Relations , Siblings , Child , Child, Preschool , Female , Humans , Male , PhenotypeABSTRACT
Although sibling interactions play an important role in children's early development, they are rarely studied in very young children with an older brother or sister with autism spectrum disorder (ASD). This study used a naturalistic, observational method to compare interactions between 18-month-old infants and their older sibling with ASD (n = 22) with a control group of 18-month-old infants and their typically developing (TD) older sibling (n = 29). In addition, role (a)symmetry and the influence of gender were evaluated. Sibling interactions in ASD-dyads were characterized by higher levels of negativity. Although somewhat less pronounced in ASD-dyads, role asymmetry was present in both groups, with the older child taking the dominant position. Finally, siblings pairs with an older sister were characterized by more positive behaviours. Since differences in sibling interactions may alter the developmental trajectories of both siblings, these early relationships should be taken into account in future ASD research and interventions.