Table 2.
Fit Statistics From the Models of Variance Components Allowing for Gene-Environment Interaction and Correlation
| Model | −2LL | df | χ2 | Δdf | p | Akaike information criterion | Bayesian information criterion |
|---|---|---|---|---|---|---|---|
| All parameters free | 32,703.7 | 20752 | — | — | — | 32,737.7 | 32,960.2 |
| Fix unique c and common e moderation pathsa | 32,708.4 | 20754 | 4.7 | 2 | n.s. | 32,734.4 | 32,904.5 |
| Fix all moderation paths | 32,826.1 | 20758 | 117.7 | 4 | < .001 | 32,848.1 | 32,992.0 |
Note: Common and unique moderation paths were possible for each of the following: (a) genetic influences, (c) shared environmental influences, and (e) nonshared environmental influences. Fixed moderation paths were constrained to 0, which means that those sources of influence were present but did not vary across the levels of the moderators. Thus, moderation on a remained free in the final model. LL = log-likelihood; Δdf = difference in degrees of freedom between the model with all parameters free and the model under consideration, on which the statistical test is based.
a
This was the best-fitting model.