Social Cognitive Profiles of Children with Autism and Their Siblings

Background: Recent studies support evidence for the Broader Autism Phenotype (BAP), defined as autism spectrum traits in the relatives of children with Autistic Spectrum Disorders (ASD). Due to the increasing demand for etiologic clarity into ASD, siblings of children with ASD are of particular interest. However, this body of research is nascent, and the social cognitive characteristics of the BAP remain largely unspecified at this time.

 Objectives: The primary aim of this investigation was to examine the social cognitive profiles of children with ASD, their siblings and neurotypical individuals. A secondary aim of this study was to help clarify possible gender differences in social cognitive profiles among children with ASD.

Methods: Children with autism, their siblings, and age-, gender-matched neurotypical individuals between the ages of 3 and 12 years were included in this study.  Social abilities of participants were assessed using the Social Responsiveness Scale (SRS), a parent-report measure of social skills, and two Social Perception subtests – Theory of Mind and Affect Recognition – of the NEPSY-II. The NEPSY-II is one of the few established neuropsychological assessments to include Social Perception subtests which have been shown to be both reliable and valid in differentiating neurotypical individuals from children with ASD. This sample was recruited as part of a study examining the neurobiology of oxytocin as it relates to social abilities in children with autism and their siblings. 

Results: A total of 178 participants were included in this investigation:  66 children with ASD, 56 siblings and 56 controls.  There were no significant age or gender differences between groups (mean age 7.33; 118 boys, 60 girls). Age was used as a covariate in all analyses. No significant differences in Theory of Mind, Affect Recognition skills, or in parent report on the Social Responsiveness Scale were observed between siblings and controls. As expected, controls performed significantly better on both Social Perception tasks compared to children with ASD [Affect Recognition: F(1,108)=10.191, p<.001, Theory of Mind: F(1,44)=13.912, p=.001]. Similarly, children with ASD performed significantly worse than their sibling counterparts on both tasks [Affect Recognition: F(1,107)=10.811, p =.001, Theory of Mind: F(1,38)= 11.525, p=.002]. Additionally, statistical examination both across and within groups failed to yield significant gender differences on social perception measures. 

Conclusions: Findings from this study suggest that siblings of children with ASD do not appear to show social deficits as measured by informant- and performance-based measures. These results suggest that siblings of children with ASD appear to be more similar on social perception tasks to neurotypical controls than to their sibling with an autism spectrum diagnosis. These observations are inconsistent with recent research suggesting a Broader Autism Phenotype in which siblings of children with ASD may exhibit more social deficits than neurotypical peers. These conflicting findings warrant additional investigations to comprehensively examine all aspects of social cognition in siblings of individuals with autism of all ages.