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Abstract

Autism is a developmental disorder marked by impairments in socialization, communication, and perseverative behavior and is associated with cognitive impairment and deficits in adaptive functioning. Research has consistently demonstrated that children with autism have deficits in adaptive functioning more severe than their cognitive deficits. This study investigates the correlates and predictors of adaptive functioning as measured by the Vineland Adaptive Behavior Scales in high- and low-functioning children with autism and their age and nonverbal IQ matched controls. Thirty-five 9-year-old children with high-functioning autism (HAD) were compared with 31 age-matched children with developmental language disorder (DLD), and 40 9-year-old children with low-functioning autism (LAD) were compared with 17 age-matched children with low IQ on adaptive functioning, IQ, autistic symptomology, and tests of language and verbal memory. Results indicate that both groups with autism were significantly impaired compared to their matched controls on Socialization and Daily Living, but not Communication and that these impairments were more pronounced in the HAD group than in the LAD group. Adaptive behavior was strongly correlated with autistic symptomology only in the HAD group. Regression analyses indicated that IQ was strongly predictive of adaptive behavior in both low-functioning groups, but tests of language and verbal memory predicted adaptive behavior in the higher functioning groups. Results suggest that IQ may act as a limiting factor for lower functioning children but higher functioning children are impaired by specific deficits, including autistic symptomology and impaired language and verbal memory.

Brief Report: The Vineland Adaptive Behavior Scales in Young Children with Autism Spectrum Disorders at Different Cognitive Levels

“…The analyses build upon existing research that has reported on the relationship between cognitive and adaptive levels (e.g., Bolte and Poustka 2002), examined profiles on the VABS within samples with autism (e.g., Carter et al 1998), compared VABS scores for individuals with autism to those of other diagnostic groups (e.g., Volkmar et al 1987), and reported on the relationship among adaptive functioning, developmental level, and severity of autism symptomatology in individuals with ASD (e.g., Liss et al 2001). …”

“…It has generally been found that cognitive and adaptive composite scores are highly correlated (e.g., Liss et al 2001;Vig and Jedrysek 1995) but also that overall adaptive functioning is lower than cognitive level, at least for higher functioning people with ASD (e.g. Bolte and Poustka 2002;Freeman et al 1991;Klin et al 2007).…”

“…However, some studies have reported equivalent Communication, Daily Living Skills, and Motor Skills across groups (e.g., Fenton et al 2003;Loveland and Kelley 1991;Schatz and Hamdan-Allen 1995). Several authors have suggested these diagnostic comparisons need to be considered within the context of the cognitive level of the study participants (e.g., Fenton et al 2003;Liss et al 2001;Schatz and HamdanAllen 1995).…”

“…Most studies suggest that adaptive functioning is positively correlated with cognitive level (sometimes measured by Verbal IQ, Performance IQ, Full Scale IQ, or Mental Age) across domains (Freeman et al 1999;Klin et al 2007;Liss et al 2001;Perry et al 2005;Schatz and Hamdan-Allen 1995), with the strongest correlations for the Communication domain (Klin et al 2007). …”

“…In addition, age has been reported to be positive correlated with VABS age equivalent scores (e.g., Carter et al 1998;Klin et al 2007) and standard scores (Liss et al 2001). However, some research suggests that age is negatively correlated with VABS standard scores, at least in some domains (e.g., Carter et al 1998;Fenton et al 2003;Klin et al 2007;Szatmari et al 2003).…”