Siblings play an important role in shaping the developmental trajectories of individuals with autism spectrum disorder. Having siblings has been associated with better social communication, non-verbal communication, and theory of mind abilities in autism spectrum disorder. However, little is known about the impact of siblings on adaptive skill…

Research regarding autistic children's sibling relationship quality is mixed, although some literature suggests poorer quality compared to children with other disabilities or who are neurotypical. Little is known about how the clinical characteristics of autistic children relate to parent perceptions of sibling relationship quality. We drew data…

Individuals with autism spectrum disorder and average IQ exhibit a widening discrepancy between lagging adaptive skills relative to their cognitive potential, but it is unknown when this discrepancy emerges in development. To address this important question, we measured adaptive and cognitive skills longitudinally, from 12-36 months, in 96…

Infant social-communicative behavior, such as gaze to the face of an interactive partner, is an important early developmental skill. Children with autism spectrum disorder exhibit atypicalities in social-communicative behavior, including gaze and eye contact. Behavioral differences in infancy may serve as early markers of autism spectrum disorder…

Demographic and clinical factors may influence assessment of autism symptoms. This study evaluated these correlates and also examined whether social communication and interaction and restricted/repetitive behavior provided unique prediction of autism spectrum disorder diagnosis. We analyzed data from 7352 siblings included in the Interactive…

There is very little known about how sibling characteristics may influence the social functioning of a child with an autism spectrum disorder (ASD). The current study utilized data from the Simons Simplex Collection (SSC; n=1355 children with ASD and 1351 siblings) to investigate this relationship. Phenotypic measures included (a) the "Autism…

Autism spectrum disorder and attention deficit hyperactivity disorder are neurodevelopmental disorders that cannot be codiagnosed under existing diagnostic guidelines ("Diagnostic and Statistical Manual of the American Psychiatric Association," 4th ed., text rev.). However, reports are emerging that attention deficit hyperactivity…

Despite the skewed sex ratio, few studies have addressed possible cognitive sex differences in autism spectrum disorders (ASDs). This study compared visual attention to detail (ATTD) and selected executive functions (EF) in 35 males and 21 females with higher-functioning ASD and unaffected sibling controls. Females with ASD outperformed males on…