APPENDIX

Table 1. Results of model fitting for INT and EXT at age 7, 10 and 12. The best fitting model is displayed in bold.

INT age 7 / INT age 10 / INT age 12
Model / -2LL / df / c / Χ2 / ∆ df / p / -2LL / df / c / Χ2 / ∆ df / p / -2LL / df / c / Χ2 / ∆ df / p
0. SAT / 40694.6 / 6807 / 37616.0 / 6116 / 25914.4 / 4312
1. ACE: 4 groups* / 40714.5 / 6817 / 0 / 19.9 / 10 / 0.03 / 37621.7 / 6126 / 0 / 5.7 / 10 / 0.84 / 25923.1 / 4322 / 0 / 8.7 / 10 / 0.56
2. ACE: ST = DT / 40856.7 / 6823 / 1 / 162.1 / 6 / 0.00 / 37778.3 / 6132 / 1 / 156.6 / 6 / 0.00 / 25987.9 / 4328 / 1 / 64.8 / 6 / 0.00
3. ACE M=F, ST / 40715.5 / 6820 / 1 / 1.0 / 3 / 0.80 / 37626.9 / 6129 / 1 / 5.2 / 3 / 0.16 / 25923.2 / 4325 / 1 / 0.1 / 3 / 0.99
4. ACE: M=F, DT / 40718.9 / 6823 / 3 / 3.4 / 3 / 0.33 / 37630.5 / 6132 / 3 / 3.6 / 3 / 0.31 / 25923.6 / 4328 / 3 / 0.4 / 3 / 0.94
5. Drop C, ST / 40718.9 / 6824 / 4 / 0.0 / 1 / 1.00 / 37631.8 / 6133 / 4 / 1.3 / 1 / 0.25 / 25923.6 / 4329 / 4 / 0.0 / 1 / 1.00
6. Drop C, DT / 40718.9 / 6825 / 5 / 0.0 / 1 / 1.00 / 37631.9 / 6134 / 5 / 0.1 / 1 / 0.75 / 25923.6 / 4330 / 5 / 0.0 / 1 / 1.00
7. Correlated errors / 40800.3 / 6819 / 0 / 105.7 / 12 / 0.00 / 37641.7 / 6131 / 0 / 25.7 / 15 / 0.04 / 25924.3 / 4327 / 0 / 9.9 / 15 / 0.83
8. Twin confusion / 40755.9 / 6822 / 0 / 61.3 / 15 / 0.00 / 37718.3 / 6128 / 0 / 102.3 / 12 / 0.00 / 25970.9 / 4324 / 0 / 56.5 / 12 / 0.00
EXT age 7 / EXT age 10 / EXT age 12
0. SAT / 44954.8 / 6914 / 41357.5 / 6218 / 28530.5 / 4359
1. ACE: 4 groups* / 44963.1 / 6924 / 0 / 8.3 / 10 / 0.60 / 41371.9 / 6228 / 0 / 14.4 / 10 / 0.16 / 28538.7 / 4369 / 0 / 8.2 / 10 / 0.61
2. ACE: ST = DT / 45069.8 / 6930 / 1 / 106.7 / 6 / 0.00 / 41500.8 / 6234 / 1 / 128.9 / 6 / 0.00 / 28607.8 / 4375 / 1 / 69.1 / 6 / 0.00
3. ACE M=F, ST / 45025.8 / 6927 / 1 / 62.7 / 3 / 0.00 / 41463.8 / 6231 / 1 / 91.9 / 3 / 0.00 / 28586.1 / 4372 / 1 / 47.4 / 3 / 0.00
4. ACE: M=F, DT / 44998.8 / 6927 / 1 / 35.7 / 3 / 0.00 / 41406.6 / 6231 / 1 / 34.7 / 3 / 0.00 / 28562.8 / 4372 / 1 / 24.1 / 3 / 0.00
5. Drop C boys, ST / 44963.4 / 6925 / 1 / 0.3 / 1 / 0.58 / 41373.4 / 6229 / 1 / 1.5 / 1 / 0.22 / 28541.9 / 4370 / 1 / 3.2 / 1 / 0.07
6. Drop C girls, ST / 44963.9 / 6926 / 5 / 0.5 / 1 / 0.48 / 41376.9 / 6230 / 5 / 3.5 / 1 / 0.06 / 28542.6 / 4371 / 5 / 0.7 / 1 / 0.40
7. Drop C boys, DT / 44965.7 / 6927 / 6 / 1.8 / 1 / 0.18 / 41380.5 / 6231 / 6 / 3.6 / 1 / 0.06 / 28543.5 / 4372 / 6 / 0.9 / 1 / 0.34
8. Drop C girls, DT / 44966.9 / 6928 / 7 / 1.2 / 1 / 0.27 / 41380.5 / 6232 / 7 / 0.0 / 1 / 1.00 / 28544.6 / 4373 / 7 / 1.1 / 1 / 0.29
9. Correlated errors / 45043.5 / 6929 / 0 / 88.7 / 15 / 0.00 / 41489.0 / 6233 / 0 / 131.5 / 15 / 0.00 / 28602.3 / 4374 / 0 / 71.8 / 15 / 0.00
10. Twin confusion / 45002.5 / 6926 / 0 / 47.7 / 12 / 0.00 / 41425.4 / 6230 / 0 / 67.9 / 12 / 0.00 / 28571.2 / 4371 / 0 / 40.7 / 12 / 0.00

* the ACE model is fitted separately to same and different teacher ratings and dependent on sex, resulting in 4 different groups. DT = different teacher; ST = same teacher; c = compared to model; M = male; F = female.

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