. Author manuscript; available in PMC: 2014 Jul 15.

Published in final edited form as: Behav Genet. 2009 Apr 18;39(3):255–264. doi: 10.1007/s10519-009-9270-3

Table 5.

Model-fitting statistics: autistic-like behaviors-orientation/engagement

Variable and model	Overall fit of model^a						Relative fit of model^b
	−2LL	df	χ ²	df	P	AIC	Δ χ ²	df	P
Saturated	3536.845	1219
Full	3553.722	1230	16.877	11	0.11	−5.123
Drop A-cov	3562.722	1231	25.877	12	0.01	1.877	9.00	1	0.003
Drop C-cov	3558.185	1231	21.340	12	0.04	−2.660	4.46	1	0.035
Drop E-cov	3556.782	1231	19.937	12	0.07	−4.063	3.06	1	0.080

−2LL likelihood statistic; χ² Chi-square fit statistic; df degrees of freedom; AIC Akaike’s information criterion; A cov genetic covariate; C cov shared environmental covariate; E cov nonshared environmental covariate

Overall fit of the model is determined by the difference in −2LL of the model and that of a saturated model

Relative fit of the model determined by the χ² difference (Δχ²) between full bivariate ACE model and reduced model