IQ as An Outcome Measure In Children with Autism Spectrum Disorder: What Are We Measuring?

Background:  

Global intellectual functioning scores are frequently used to evaluate the effects of behavioral interventions for children with autism spectrum disorder (Eldevik, Jahr, Eikeseth, Hastings, & Hughes, 2010). Although this has become standard practice, administering IQ tests to children with ASD can be extremely difficult and potentially result in invalid scores due to behavioral symptoms common to individuals on the spectrum including limited attention, limited expressive and receptive communication, disruptive behaviors (such as task avoidance and escape behaviors), and lack of motivation (Dietz, Swinkels, Buitelaar, Daalen, & Engeland, 2007; Koegel, Koegel, & Smith, 1997).  Therefore, researchers suggest that cognitive assessments fail to capture intelligence and thus become measurements of motivation, attention, and compliance (Koegel & Koegel, 1995).  As a result, increases in IQ scores may actually reflect a decrease in problematic behavior, and not improved cognitive ability. 

Objectives:  

This pilot study evaluated the extent to which problem behavior was related to IQ scores by collecting data on both (IQ and problem behavior) during the IQ testing session to analyze the relationship between the two. That is to say, we hypothesized that comparatively low IQ scores were more likely to correlate with comparatively higher scores on problem behavior, and conversely, high IQ would more be more likely to correlate with low problem behavior.

Methods:  

The participants in the study included all identified students in the kindergarten through second grade autistic support classrooms in a large mid-Atlantic school district. All students met the criteria for autism including children with an autism spectrum disorder, autism, or pervasive developmental disorder.  A total of 255 students were administered the Differential Abilities Scale, Second Edition and the study researchers completed a Behavioral Rating Form immediately after the assessment. 

Results:  

The relationship between overall IQ scores and challenging behaviors was evaluated. In addition, data were analyzed to determine if specific cognitive profiles had a stronger relationship to problem behaviors.

Conclusions:  

Analysis is ongoing; preliminary results suggest that there is a negative correlation with the occurrence of undesired behaviors and IQ score.  Future directions should assess the remediation of high frequency undesired behaviors and its subsequent effect on measures of intelligence.