Characterizing Adaptive Behavior in Young Children with Autism: Exploring the Gap between IQ and Adaptive Behavior

Background: Children with autism spectrum disorder (ASD) present with impairments in adaptive behavior, particularly, socialization skills (Kanne et al., 2011); however, evidence for a unique “autism profile” of adaptive behavior has yet to be consistently established (Pathak et al., 2017). More fully characterizing the adaptive behavior of young children with ASD has important implications, as this domain is associated with more positive outcome in adulthood (Bishop et al., 2016; Farley et al., 2009).

Objectives: The primary purpose of this study was to characterize adaptive behavior in relation to cognitive functioning in a community-ascertained sample of young children with ASD.

Methods: A total of 150 children who received a best-estimate diagnosis of ASD at three were included in this sample to date. It is anticipated an additional 80 children will be added prior to the conference presentation. All children were recruited as part of the ongoing, prospective FIRST WORDS^® Project (Delehanty et al., 2018; Dow et al., 2017; Wetherby et al., 2008), which screens for ASD and communication delays in primary care settings. Children in the sample were primarily male (n = 120) with an average age of 36.02 months (SD = 2.93). The evaluation battery included the Autism Diagnostic Observation Schedule (Lord et al., 1999), the Mullen Scales of Early Learning (MSEL; Mullen, 1995) and the Vineland Adaptive Behavior Scales, 2^nd edition (VABS-II; Sparrow et al., 2005).

Results: Preliminary descriptive analysis of this community sample revealed variability in regard to autism symptomology, cognitive functioning (M= 73.67, SD= 23.68), and adaptive behavior (M = 77. 15, SD = 10.40). With regard to adaptive behavior, children demonstrated significant strengths in Communication (M = 82.61, SD = 15.30) and Motor Skills (M = 81.75, SD = 10.77) relative to Daily Living Skills (M = 79.97, SD = 10.42) and Socialization (M = 76.73, SD = 10.27). Consistent with previous research (Kanne et al., 2011; Perry et al., 2009), children with higher cognitive functioning (IQ > 70, n = 70) evidenced an IQ advantage over adaptive behavior across domains and the opposite pattern was observed for children with lower cognitive functioning. Exploratory examinations of the gap between the Adaptive Behavior Composite and IQ indicated approximately 55.3% (n = 83) of the sample presented with standard scores within one standard deviation (±15 points) of each other, 22.0% within 1.5, and 22.7% (n = 33) showed differences of greater than 1.5 standard deviations between scores. Observations indicated the size of discrepancy between composites was more strongly associated with cognitive ability (r =.911) than with adaptive behavior (r = .338).

Conclusions: Results of this study demonstrate a pattern of adaptive behavior with strengths in Communication and Motor Skills in a community sample of children with ASD. With regard to the cognitive functioning and adaptive behavior, findings suggest the size of the gap is likely accounted for by large variability in IQ compared to the relatively narrower range of adaptive functioning ability. Findings will be discussed in view of clinical implications and future research directions.