Table 4.

Table 4a. Bivariate model fit statistics for narrow anorexia nervosa and narrow bulimia nervosa.
Model No.	Model	-2lnL	df	χ² diff (df)	AIC
I	ACE-ACE, r_a r_c r_e	1308.03	13957	---	−26605.97
II	ACE-ACE, r_c r_e	1311.80	13958	3.77 (1)	−26604.20
III	ACE-ACE, r_a r_e	1308.03	13958	0.00 (1)	−26607.97
IV	ACE-AE, r_a r_e	1308.03	13959	0.00 (2)	−26609.97
V	AE-AE, r_a r_e (best fit)	1308.03	13960	0.00 (3)	−26611.97
VI	AE-AE, r_a	1310.24	13961	2.21 (4)	−26611.76
VII	CE-CE, r_c r_e	1312.55	13960	4.52 (3)	−26607.45
VIII	E-E, r_e	1343.53	13963	35.50 (6)^*	−26582.48

Table 4b. Bivariate model fit statistics for broad anorexia nervosa and broad bulimia nervosa.
Model No.	Model	-2lnL	df	χ² diff (df)	AIC
I	ACE-ACE, r_a r_c r_e	3610.96	13926	---	−24241.05
II	ACE-ACE, r_c r_e	3618.22	13927	7.26 (1)^*	−24235.78
III	ACE-ACE, r_a r_e	3610.96	13927	0.00 (1)	−24243.05
IV	ACE-AE, r_a r_e	3610.96	13928	0.00 (2)	−24245.05
V	AE-AE, r_a r_e(best fit)	3610.96	13929	0.00 (3)	−24247.05
VI	AE-AE, r_a	3634.67	13930	23.71 (4) ^*	−24225.33
VII	CE-CE, r_c r_e	3622.55	13929	11.59 (3) ^*	−24235.46
VIII	E-E, r_e	3671.23	13932	60.28 (6) ^*	−24192.77

Note. AIC = Akiake’s Information Criterion (25); −2lnL = −2 log likelihood; df = degrees of freedom; ACE = additive genetic, shared (or common) environment, and unique environmental effects model; AE = additive genetic and unique environmental effects model; CE = shared (or common) and unique environmental effects model; E = unique environmental effects model; r_a = genetic correlation between AN and BN; r_c = shared environmental correlation between AN and BN; r_e = unique environmental correlation between AN and BN

p < .05.