. Author manuscript; available in PMC: 2021 Feb 1.

Published in final edited form as: Alcohol Clin Exp Res. 2020 Jan 13;44(2):522–531. doi: 10.1111/acer.14262

Table 4.

Results From Biometric Models Partitioning the Variation in High-Intensity Drinking Propensity Into Genetic (A), Common (C), and Individual-Specific (E) Environmental Factors

		Men			Women			Model fit
Model	r_g	A²	C²	E²	A²	C²	E²	χ²	df	p
1) ACE free, r_g DZO free
Estimate	0.01	0.38	0.00	0.62	0.41	0.00	0.59	36.25	33	.32
95% CI	0, 0.50	0.01, 0.55	0.00, 0.47	0.47, 0.76	0.17, 0.54	0.00, 0.36	0.48, 0.70
2) ACE free, r_g DZO fixed
Estimate	0.50	0.34	0.00	0.65	0.39	0.00	0.61	39.22	34	.25
95% CI	Fixed	0.00, 0.52	0.00, 0.50	0.50, 0.82	0.00, 0.50	0.00, 0.44	0.50, 0.73
3) ACE fixed, r_g DZO free
Estimate	0.01	0.40	0.00	0.60	0.40	0.00	0.60	37.29	35	.36
95% CI	0, 0.50	0.28, 0.50	0.00, 0.15	0.51, 0.69	0.28, 0.50	0.00, 0.15	0.51, 0.69
4) ACE fixed, r_g DZO fixed
Estimate	0.50	0.37	0.00	0.63	0.37	0.00	0.63	40.34	36	.28
95% CI	Fixed	0.28, 0.46	0.00, 0.00	0.54, 0.72	0.28, 0.46	0.00, 0.00	0.54, 0.72

All models included age as a covariate. Bold indicates significant parameter estimate. CI = confidence interval, DZO = opposite-sex dizygotic twins, r_g = correlation between genetic influences in opposite-sex twin pairs.