Table 2.

WISC-IV indices for split-half groups with higher and lower FSIQ with p values of pairwise comparisons with the PSI and effect size for each index

Index score	FSIQ ≥ 100a				FSIQ ≤ 99b
	M	SD	p	Effect size	M	SD	p	Effect size
VCI	113.65	11.22	< 0.001***	0.567	94.12	11.14	0.008**	0.331
PRI	114.31	11.20	< 0.001***	0.583	95.98	12.12	0.001*	0.383
WMI	101.82	13.17	0.631	0.161	91.75	9.67	0.081	0.256
PSI	97.71	11.93			86.00	11.96
FSIQ	110.53	8.63	< 0.001***	0.524	89.77	7.74	0.165	0.161

M mean, SD standard deviation, WISC-IV Wechsler intelligence scale for children, fourth version, PRI perceptual reasoning index, VCI verbal comprehension index, WMI working memory index, PSI processing speed index, FSIQ full-scale intelligence quotient, ADOS autism diagnostic observation scale, ADI-R autism diagnostic interview—revised

^an = 49

^bn = 52

*p < 0.05

**p < 0.01

***p < 0.001