The Broader Autism Phenotype in the First Two Years: Maternal Reports and Play Behaviors

Background: In families raising a child with an autism spectrum disorder (ASD), younger siblings are at elevated risks for ASD, and other developmental concerns including subclinical ASD features, often called the Broader Autism Phenotype (BAP). In adults and children aged 3 years or older, self- or parent-report questionnaires are often used to characterize the BAP. For children under 3, clinical judgments and standardized developmental assessments typically inform impressions of the BAP. Recent work has expanded our understanding of the BAP in early childhood by documenting observed dyadic social difficulties as early as 15 months of age. However, less is known about maternal reports of BAP-aligned social difficulties in young children and how that may inform their play interactions.

Objectives: Within this study we expand our developmental understanding of the BAP in early childhood by examining (1) maternal reports of social communication difficulties in their children, compared to typically developing peers, and (2) if reported social difficulties inform mothers’ approaches to play, within a social context.

Methods: As part of a prospective study, dyads were recruited from families with at least one older child with ASD (high-risk group, n = 36), and families with no history of ASD (low-risk group, n = 38). During laboratory visits at 12, 15, 18, and 24 months of age children completed a series of standardized assessments and a mother-child play interaction. At each visit, child socialization and communication skills were mother-reported via the Vineland Adaptive Behavior Scales (VABS). Play interactions were rated with the Joint Engagement Rating Inventory (JERI). Between 24 and 36 months, children completed an outcome visit and, following previously established criteria, children were assigned to BAP (n = 22) and TYP (n = 52) groups.

Results: A series of ANCOVAS were conducted, with terms for infant sex and maternal education as covariates, and revealed significant group differences on select standardized measures and indices of play from 12 to 24 months of age. Group comparisons revealed differences between the BAP and TYP outcome groups by 24 months in mother-reported socialization, F(1, 68) = 4.22, p = .04, partial η2 = .06, and communication F(1, 68) = 5.71, p = .02, partial η2 = .08. By 15 months, mothers in the BAP group exhibited less symbol highlighting, F(1, 30) = 5.71, p = .02, partial η2 = .17, and following-in, F(1, 30) = 5.33, p = .03, partial η2 = .17. Mothers in the BAP group also exhibited more affective communication by 12 months, F(1, 24) = 5.85, p = .03, partial η2 = .23. These results were not consistent across visits (Figure 1).

Conclusions: Overall, this study provides detailed information on early social interactions in the BAP, which may inform intervention and differential diagnosis efforts. By examining group differences across four time-points, the current study demonstrates that distinct patterns exist between BAP and TYP. Recognizing the increasing demand for parent-mediated elevated-risk interventions, these findings highlight several social constructs through which interventions may promote optimal development in children developing at risk.