Table 2.

Descriptive Statistics, Shared Variables, by MZ Twin Status

	Twins (Imputed, N=578)					Full Sample (Unimputed, N=20,715)
	Mean	SD	Range			Mean	SD	Range
Demographics & Family Structure
Age	16.21	1.55	13	-	20	16.16	1.72	11	-	21
Full Siblings*	3.22	1.13	1	-	9	2.61	1.50	1	-	15
HH Females*	0.84	0.77	0	-	3	0.55	0.78	0	-	8
Birth Order*	1.28	1.04	0	-	7.5	1.07	1.29	0	-	14
HH Size*	4.03	1.46	0	-	12	3.60	1.66	0	-	17
Non-White	0.46	--	0	-	1	0.48	--	0	-	1
Parents Married	0.59	--	0	-	1	0.59	--	0	-	1
Sibling Age SD*	1.81	1.75	0.0	-	9.0	1.55	2.08	0.0	-	50.5
Immigrant*	0.08	--	0	-	1	0.09	--	0	-	1
Neighborhood Characteristics
Bad Neighborhood	5.69	2.32	3	-	14	5.40	2.25	3	-	14
Home Value Disp.	36024	26710	0	-	159580	38370	27144	4190	-	216343
Social Capital	4.31	1.29	2	-	6	4.40	1.30	2	-	6
Unemployment	0.07	0.06	0.00	-	0.34	0.08	0.06	0.00	-	0.59
Urban*	0.63	--	0	-	1	0.57	--	0	-	1
School Characteristics
Bad School	0.18	0.26	0.0	-	1.1	−0.02	0.52	−1.8	-	0.9
Social Cohesion	2.31	0.60	0.3	-	4.5	2.46	0.20	1.6	-	3.1
%College Attend.*	61.56	21.74	5	-	130	63.72	22.19	5	-	100
Size*	0.57	0.50	0	-	1	2.35	0.72	1	-	3
Race Segregation	0.28	0.19	0.00	-	1.06	0.27	0.18	−0.00	-	0.75
Parental Characteristics
Education
<8th*	0.10	--	0	-	1	0.10	--	0	-	1
HS/Eq.*	0.20	--	0	-	1	0.16	--	0	-	1
Some College	0.26	--	0	-	1	0.28	--	0	-	1
≥Four Year Deg.	0.13	--	0	-	1	0.15	--	0	-	1
Unempd./Welfare	0.29	--	0	-	1	0.27	--	0	-	1
White Collar	0.64	--	0	-	1	0.66	--	0	-	1
Health Status	2.42	1.96	0	-	6	2.35	2.07	0	-	6
Risky Behavior*	1.19	1.09	0	-	4	1.07	0.99	0	-	4
Social Support & Parenting
Pos. Relationship	1.01	0.75	0	-	2	0.94	0.83	0	-	2
Neg. Relationship	0.81	0.61	0	-	2	0.82	0.68	0	-	2
Par. School Involve.	1.76	1.01	0	-	3	1.56	1.11	0	-	3
Parental Control	2.21	1.13	−1	-	6	2.12	1.33	0	-	6
Social Support*	0.00	0.64	−1.0	-	1.6	0.00	0.60	−1.1	-	1.5

^*MZ-Full Sample t-test p<.05

NOTE: MZ twin values which are outside the full sample range are the result of imputation procedures.