Table 1. Goodness-of-fit tests for models retaining 1 to 20 factors from an analysis of 93 traits (N = 13,138).

Number of Factors	Residual df	Chi-square related tests			Residual correlations			Variance explained
		χ2	RMSEA	CFI	SRMR	>0.1	>0.05
Null	4278	602645	0.103	0.000	0.262	73.7	93.9	0.0
1	4185	347777	0.079	0.426	0.084	12.7	37.0	44.2
2	4093	278850	0.071	0.541	0.067	7.0	26.7	55.8
3	4002	230499	0.066	0.621	0.055	4.5	18.4	64.5
4	3912	198199	0.061	0.675	0.048	2.8	14.7	70.7
5	3823	172549	0.058	0.718	0.041	2.2	10.1	76.5
6	3735	155107	0.056	0.747	0.037	1.9	8.6	80.7
7	3648	139399	0.053	0.773	0.033	1.8	6.5	84.7
8	3562	124820	0.051	0.797	0.030	1.5	6.0	87.6
9	3477	111664	0.049	0.819	0.028	1.2	4.9	90.3
10	3393	101096	0.047	0.837	0.026	1.1	4.1	92.7
11	3310	89025	0.044	0.857	0.024	0.9	3.6	95.1
12	3228	82315	0.043	0.868	0.022	0.7	3.0	97.0
13	3147	76152	0.042	0.878	0.020	0.6	2.3	98.9
14	3067	71111	0.041	0.886	0.018	0.4	2.0	100.7
15	2988	67511	0.041	0.892	0.017	0.2	1.7	102.3
16	2910	64403	0.040	0.897	0.016	0.2	1.4	103.6
17	2833	62037	0.040	0.901	0.014	0.2	1.3	104.9
18	2757	58874	0.039	0.906	0.013	0.1	1.1	106.0
19	2682	56837	0.039	0.909	0.012	0.1	0.9	107.0
20	2608	55531	0.039	0.912	0.012	0.1	0.7	107.8

CFI = Comparative Fit index.

RMSEA = Root mean square error of approximation.

SRMR = Standardised root mean square residual.

All the model χ² values were highly significant (p<0.0001). For the 7 factors in this study, the overall fit statistics suggested a reasonable to good fit. Examination of the 66 residual correlations >0.1 showed that they clustered within the factor structure: 6 related to Factor 2 variables 6–24 m (6.6% of all inter-correlations within this group), 7 (19.4%) related to Factors 1/2 variables 30–42 m, 8 (7.6%) related to Factor 1 variables 57 m–9y, 4 (8.9%) to Factor 3 variables, 10 (12.8%) to Factor 4, 7 (19.4%) to Factor 5, 12 (21.8%) to Factor 6 and 12 (18.2%) to Factor 7.

The variance explained is expressed as a percentage of the sum of the communalities. This latter measure can exceed 100% due to the presence of negative eigenvalues. Residual correlations >0.1 and >0.05 are reported as a percentage of the 4278 pairwise correlations.