Table 4.
Moderator Analyses
| Moderator Variables | χ2 | df | p-value | AIC | A | C | D | E |
|---|---|---|---|---|---|---|---|---|
| Assessment Method | ||||||||
| Parameters free | 1270.36 | 434 | <.001 | 402.36 | ||||
| Questionnaires | .38 | .00 | .11 | .51 | ||||
| Laboratory Measures | .19 | .04 | .28 | .49 | ||||
| Parameters constrained | 1271.14 | 438 | <.001 | 395.14 | .38 | .00 | .12 | .50 |
| Difference in χ2 | 0.78 | 4 | 0.95 | |||||
| Age (4-groups) | ||||||||
| Parameters free | 1094.75 | 426 | <.001 | 242.75 | ||||
| Infants | .28 | .00 | .25 | .47 | ||||
| Children | .47 | .00 | .12 | .41 | ||||
| Adolescents | \ | .31 | .02 | .23 | .46 | |||
| Adults | .31 | .00 | .10 | .59 | ||||
| Parameters constrained | 1271.14 | 438 | <.001 | 395.14 | .38 | .00 | .12 | .50 |
| Difference in χ2 | 176.4 | 12 | <.001 | |||||
| Age (3-groups without infants) | ||||||||
| Parameters free | 989.69 | 373 | <.001 | 243.69 | ||||
| Children | .47 | .00 | .12 | .41 | ||||
| Adolescents | .31 | .00 | .23 | .46 | ||||
| Adults | .31 | .00 | .07 | .59 | ||||
| Parameters constrained | 1163.89 | 381 | <.001 | 401.89 | .38 | .00 | .11 | .51 |
| Difference in χ2 | 174.20 | 8 | <.001 | |||||
| Sex (with Opposite Sex twins) | ||||||||
| Parameters free | 956.70 | 254 | <.001 | 448.70 | ||||
| Males | .45 | .00 | .19 | .36 | ||||
| Females | .09 | .05 | .35 | .51 | ||||
| Parameters constrained | 1211.51 | 258 | <.001 | 695.507 | .08 | .01 | .50 | .41 |
| Difference in χ2 | 254.81 | 4 | <.001 | |||||
| Sex (without Opposite Sex twins) | ||||||||
| Parameters free | 640.28 | 221 | <.001 | 198.28 | ||||
| Males | .41 | .00 | .12 | .47 | ||||
| Females | .23 | .00 | .26 | .51 | ||||
| Parameters constrained | 651.72 | 225 | <.001 | 201.72 | .29 | .01 | .20 | .50 |
| Difference in χ2 | 11.44 | 4 | 0.02 | |||||
| Twin vs. Family/Adoption Studies | ||||||||
| Parameters free | 1218.03 | 434 | <.001 | 350.03 | ||||
| Twin | .14 | .07 | .29 | .50 | ||||
| Family/Adoption | .00 | .04 | .00 | .96 | ||||
| Parameters constrained | 1271.14 | 438 | <.001 | 395.14 | .38 | .00 | .12 | .50 |
| Difference in χ2 | 53.11 | 4 | <.001 | |||||
| Publication Date | ||||||||
| Parameters free | 1266.86 | 434 | <.001 | 398.86 | ||||
| 1970–1985 | .28 | .00 | .18 | .54 | ||||
| 1986–2011 | .385 | .00 | .115 | .50 | ||||
| Parameters constrained | 1271.14 | 438 | <.001 | 395.14 | .38 | .00 | .12 | .50 |
| Difference in χ2 | 4.28 | 4 | .37 | |||||
Note. AIC= Akaike Information Criterion; A= additive genetic effects; C=shared environmental effects; E= nonshared environmental effects; D=nonadditive genetic effects.