Dia 1

1
Netherlands Twin Register (NTR)
30,000 twin pairs registered at birth, born after
1986
Questionnaire variables Zygosity, health and
growth 2, 3, 5, 7, 10, 12, (14, 16) SES
3, 7, 10, 12 Problem behavior
CBCL (Devereux at 5) 3, 5, 7, 10,
12 TRF 7, 10, 12 YSR
12, (14, 16) Motor development 2,
5 School achievement 5,
12, (14, 16) Family Composition
5, 12, (14, 16)
2
Aggressive and Rule-Breaking Behavior
3
Table 1 CBCL-items of the syndrome Aggressive
Behavior for the CBCL/2-3 and CBCL/4-18
Aggressive Behavior 10 year old twins rated by
their mother
skewness 1.346
4
Table 1 CBCL-items of the syndrome Aggressive
Behavior for the CBCL/2-3 and CBCL/4-18
Square root transformed Aggressive Behavior 10
year old twins rated by their mother
skewness .046
5
Table 1 CBCL-items of the syndrome Aggressive
Behavior for the CBCL/2-3 and CBCL/4-18
SPSS descriptives
Pairs Ma Mb Vara Varb r MZM 514 2.41 2.38 1.62
1.56 .84 DZM 467 2.24 2.31 1.62 1.50 .50 MZF
609 1.98 1.90 1.31 1.28 .79 DZF 452 1.95 1.91 1.
36 1.26 .54 DOSm-f 885 2.23 1.81 1.57 1.29 .47
6
Table 1 CBCL-items of the syndrome Aggressive
Behavior for the CBCL/2-3 and CBCL/4-18
Mx Means and Variance (Saturated)
Males -2LL df par ??2 df p AIC means
free 5712.15 1956 10 eq means 5716.90
1959 7 4.755 3 .191 -1.245 eq m/ eq v 5718.77
1962 4 6.622 6 .357 -5.378
Females -2LL df par ??2 df p AIC means
free 5844.97 2120 10 eq means 5854.08
2123 7 9.110 3 .028 3.11 eq m/ eq v 5855.33
2126 4 10.360 6 0.110 -1.64 eq v 5846.23
2123 7 1.257 3 0.139 -4.74
Males/Females -2LL df par ??2 df p AIC means
free 11557.121 4076 20 eq means 11636.350
4083 13 79.229 7 .000 65.229 eq m/ eq v 11652.008
4090 6 94.887 14 .000 66.887 eq v 11572.401
4083 13 15.280 7 .033 1.280
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Table 1 CBCL-items of the syndrome Aggressive
Behavior for the CBCL/2-3 and CBCL/4-18
Mx Estimates of Means and Variances
T1 T2 VT1 VT2 r r (eq m) MZF 1.99 1.90 1.31 1.2
8 .792 .789 DZF 1.95 1.91 1.36 1.26 .538 .537 MZ
M 2.41 2.38 1.61 1.56 .83 DZM 2.24 2.30 1.61 1.4
9 .50
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Table 1 CBCL-items of the syndrome Aggressive
Behavior for the CBCL/2-3 and CBCL/4-18
Mx Means and Variance (Saturated) SS and OS twins
Males/Females -2LL df par ??2 df p AIC 16997.
749 5845 25 eq m ssm 17002.503 5848
22 4.755 3 .191 -1.245 ss/os
17005.925 5849 21 8.176 4 .085 0.176 eq m
ssf 17006.859 5848 22 9.110 3 .028 3.110 ss /
osf 17012.611 5849 21 14.862 4 .005 6.862
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Table 1 CBCL-items of the syndrome Aggressive
Behavior for the CBCL/2-3 and CBCL/4-18
Model Fitting Results
Boys -2LL df ?2 ?df A C E ACE 5713.827 1959 .6
7 .17 .16 AE 5719.542 1960 5.72 1 .84 - .16 CE 586
4.235 1960 150.4 1 - .68 .32
Girls -2LL df ?2 ?df A C E ACE 5846.232 2123 .
52 .28 .21 AE 5861.720 2124 15.49 1 .80 - .20 CE 5
936.009 2124 89.77 1 - .68 .32