Table 2.

Decomposition of Variance for the Higher Order Four-Factor Model of the WISC-IV in a Neuropsy-chology Clinic Sample (N = 344)

Subtests	g		VC		PR		WM		PS		h2	u2
	B	var	B	var	B	var	B	var	B	var
Similarities	0.72	52	0.41	17							0.68	0.32
Vocabulary	0.79	63	0.45	20							0.83	0.17
Comprehension	0.69	47	0.39	15							0.62	0.38
Block Design	0.67	44			0.28	8					0.52	0.48
Picture Concepts	0.68	46			0.28	8					0.55	0.46
Matrix Reasoning	0.73	53			0.30	9					0.62	0.38
Digit Span	0.69	48					0.11	1			0.49	0.51
Letter-Number	0.73	53					0.11	1			0.54	0.46
Digit Symbol Coding	0.60	36							0.54	29	0.65	0.35
Symbol Search	0.65	42							0.59	34	0.76	0.24
% Total Var		48.3		5.2		2.5		0.2		6.4	62.6	37.4
% Common Var		77.2		8.3		4.0		0.4		10.2

Note. Loadings and variances for first-order factors are after accounting for the indirect effects of the higher order general intelligence factor. g = general intelligence factor; VC = verbal comprehension factor; PR = perceptual reasoning factor; WM = working memory factor; PS = processing speed factor; B = loading of the subtest on the factor; var = percent variance explained in the subtest; h² = communality; u² = uniqueness.