Descriptive statistics for age, cognitive ability and autism symptomatology measures.

aNonverbal and verbal IQ were measured with the WASI [65]: Matrix Reasoning and Block Design (nonverbal IQ) and Similarities and Vocabulary (verbal IQ). Full-scale IQ (FSIQ) was derived by standardizing the sum of both verbal and performance ability scores against age-based norms.bHigher scores on both the SCQ [38] and ADOS-2 [40] indicate a greater degree of autism symptomatology.cADOS-2 score reported = Communication+Social Interaction algorithm total (cut-off = 7).dAccuracy (total percentage correct) on the Cambridge Face Memory Test - for Children [41].eEqual variances not assumed.fOne-tailed independent samples t-test.