Table 1.

Means and Variances of Five Substance Use Phenotypes.

				Means					Variances
Sample	Sex	N	Age	NIC	CON	DEP	DRG	BD	NIC	CON	DEP	DRUG	BD
			M (SD)
Twin Families
Parents	Male	1396	43.87 (5.65)	.53	.80	.86	.41	.63	1.16	.42	1.64	1.36	1.10
	Female	1587	41.67 (5.15)	.18	.09	−.06	−.01	−.33	1.11	.35	.63	.83	.55
MZ Twins	Male	873	17.80 (0.61)	−.21	−.23	−.25	−.17	.24	.70	1.38	.63	.90	1.17
	Female	990	17.88 (0.77)	−.44	−.64	−.51	−.39	−.44	.53	1.0	.25	.47	.66
DZ Twins	Male	457	17.75 (0.49)	−.22	−.35	−.26	−.18	.25	.70	1.45	.61	.92	1.21
	Female	557	18.03 (0.81)	−.32	−.49	−.40	−.28	−.26	.65	1.05	.46	.65	.82
Adoptive Families
Parents	Male	384	48.43 (4.46)	.22	.49	.44	.45	.22	1.13	.49	1.21	1.35	.73
	Females	485	46.53 (4.11)	−.18	−.11	−.21	.04	−.50	.91	.32	.47	.78	.28
Bio Sibs	Male	168	18.16 (1.01)	−.26	−.14	−.09	.15	.35	.65	1.52	.78	1.37	1.31
	Female	194	18.33 (1.14)	−.46	−.49	−.37	−.15	−.27	.46	1.05	.41	.72	.76
Adopted Sibs	Male	50	18.54 (0.87)	.09	.13	.05	.45	.68	.79	1.33	.98	1.47	1.20
	Female	47	18.37 (1.05)	−.24	−.25	−.29	.04	−.02	.51	.80	.61	.73	.59

Each variable in the full sample was scaled to have mean zero and variance one. NIC = Nicotine Use/Dependence; CON = Alcohol Consumption; DEP= Alcohol Dependence; DRG = Drug Dependence; BD = Behavioral Disinhibition; BD = Behavioral Disinhibition. MZ stands for monozygotic twins and DZ stands for dizygotic twins.