ABSTRACT
OBJECTIVE: The purpose of this study is to identify whether the well-described pattern of declining adaptive functioning across age among children with autism spectrum disorder (ASD) also exists among intellectually gifted children with ASD because their cognitive abilities might serve as a protective factor. METHODS: Data from the Simons Simplex Collection were used to identify 51 participants with full-scale intelligence (IQ) scores of 130 or above with this group labeled as the intellectually gifted range (IGR). Two comparison samples of children with IQs in the intellectual disability range (IDR; < 70 Standard Score [SS]) and average range (AR; 85-115 SS) were created based on matching of age (±2 years), maternal education level, and sex. RESULTS: Multivariate analysis of variance indicated a main overall effect for the IQ group on a measure of adaptive skills (Λ = 0.61, F(6, 296), p < 0.001). Post hoc comparisons revealed that the IDR group scored lower on all subscales than the AR and IGR groups, but the scores between the latter groups did not differ from one another in socialization and daily living skills (DLS) domains. Age was negatively correlated with adaptive communication scores in all groups but only associated with socialization and DLS domain scores in the IGR group (r = -0.51 and -0.48, respectively). CONCLUSION: The findings suggest that intellectual giftedness does not serve as a protective factor against age-related declines in adaptive functioning among individuals with ASD.