Table 2.
Model Fit Indices.
| Model Fit Statistics |
||||
|---|---|---|---|---|
| Model | −2lnL (df) | Δχ2 (Δdf) | p | AIC |
| Initial Moderation Analyses | ||||
| Full Moderation (Quadratic and Linear) | 3239.53 (1172) | -- | -- | 895.53 |
| No Moderation | 3262.18 (1178) | 22.65 (6) | <.001 | 906.18 |
| Alternative Moderation Models | ||||
| Drop Quadratic C and E Moderation | 3240.57 (1174) | 1.04 (21) | .31 | 892.57 |
| Linear Moderation | 3244.65 (1175) | 5.11 (3) | .16 | 894.64 |
| Post-Hoc Moderation Analyses | ||||
| Separating Mid-to-Late Puberty and Post-Puberty Groups | ||||
| Full Moderation (Quadratic and Linear) | 3225.98 (1172) | -- | -- | 881.98 |
| No Moderation | 3254.40 (1178) | 28.42 (6) | <.001 | 898.40 |
| Alternative Moderation Models | ||||
| Drop Quadratic C and E Moderation | 3226.22 (1174) | 0.24 (2) | .89 | 878.22 |
| Linear Moderation | 3235.12 (1175) | 9.14 (3) | .03 | 885.12 |
| Removal of Adrenarcheal Twins Ages 6-7 | ||||
| Full Moderation (Quadratic and Linear) | 2116.59 (778) | -- | -- | 560.59 |
| No Moderation | 2130.29 (784) | 13.70 (6) | .03 | 562.29 |
| Alternative Moderation Models | ||||
| Drop Quadratic E Moderation | 2117.01 (779) | 0.42 (1) | .52 | 559.01 |
| Drop Quadratic C and E Moderation | 2117.41 (780) | 0.82 (2) | .66 | 557.41 |
| Linear Moderation | 2127.09 (781) | 10.50 (3) | .01 | 565.09 |
Note: Full Moderation Model = allows genetic, shared environmental, and nonshared environmental estimates to vary both linearly and quadratically across levels of the moderator; No Moderation Model = constrains genetic, shared environmental, and nonshared environmental estimates to be equal across the moderator; Linear Moderation Model = allows genetic, shared environmental, and nonshared environmental estimates to only vary linearly across levels of the moderator; Drop Quadratic C and E Moderation Model = retained all linear moderation and the quadratic moderation of genetic influences, but dropped quadratic moderation of shared and nonshared environmental influences. Drop Quadratic E Moderation Model = retained all linear moderation and the quadratic moderation of genetic and shared environmental influences, but dropped quadratic moderation of nonshared environmental influences. A = additive genetic, C = shared environment, E = nonshared environment; −2lnL= −2 times the log likelihood; df= degrees of freedom; Δχ2 = change in chi-square, via differences in −2lnL, from the least restrictive moderation model (i.e., full moderation model); Δdf = change in degrees of freedom from the least restrictive moderation model (i.e., full moderation model). AIC =Akaike Information Criterion. To evaluate model fit, each nested model is compared to the full moderation model when calculating the change in −2lnL and degrees of freedom. The ‘Drop quadratic C and E moderation model’ was best-fitting in the initial moderation analyses and the post-hoc analyses. A significant p-value for Δχ2 indicates significantly worse fit of the more restrictive model.