Table 4.
Results from Sibling-Comparison Models Testing for Genetic Confounding
| Physical Health Problemsa | Depressive Symptomsa | Educational Attainmentb | Income Attainmentb | Alcohol Problemsc | Antisocial Behaviord | |
|---|---|---|---|---|---|---|
| MIDUS | ||||||
| Main Effects | ||||||
| Between-Family Effect | .23 | .44* | −2.01** | .43 | .60 | 1.00** |
| (−.24 to .71) | (.06 to .83) | (−2.78 to −1.24) | (−.33 to 1.19) | (−.12 to 1.32) | (.45 to 1.55) | |
| Within-Family Effect | .17 | 2.50* | −2.53 | .77 | 1.27 | −.58 |
| (−1.39 to 1.73) | (.59 to 4.41) | (−10.16 to 5.11) | (−3.95 to 5.49) | (−1.91 to 4.46) | (−2.84 to 1.68) | |
| Zygosity | .29* | −.14 | −.89** | −.32 | −.25 | .05 |
| (.03 to .56) | (−.36 to .08) | (−1.12 to −.65) | (−.96 to .32) | (−.89 to .39) | (−.24 to .33) | |
| Interaction Effects | ||||||
| Zygosity × Within-Family Effect | −.53 | −1.30* | .45 | .14 | −.28 | 1.21 |
| (−1.69 to .62) | (−2.46 to −.14) | (−3.93 to 4.84) | (−3.01 to 3.28) | (−2.48 to 1.91) | (−.26 to 2.69) | |
| Add Health | ||||||
| Main Effects | ||||||
| Between-Family Effect | .13** | .36* | −.88** | −.67** | −.01 | .61** |
| (.06 to .21) | (.10 to .62) | (−1.14 to −.61) | (−.92 to −.43) | (−.09 to .07) | (.41 to .81) | |
| Within-Family Effect | .10 | .38 | −.35 | −.09 | .11 | −.29 |
| (−.13 to .33) | (−.43 to 1.19) | (−1.07 to .38) | (−.84 to .67) | (−.33 to .55) | (−.91 to .33) | |
| Zygosity | .03 | −.17* | −.11 | −.16* | .04 | .02 |
| (−.01 to .07) | (−.29 to −.04) | (−.20 to −.01) | (−.29 −.03) | (.00 to .07) | (−.12 to .16) | |
| Interaction Effects | ||||||
| Zygosity × Within-Family Effect | −.02 | .06 | .03 | −.08 | −.01 | .17 |
| (−.11 to .08) | (−.24 to .36) | (−.92 to −.43) | (−.33 to .18) | (−.16 to .15) | (−.07 to .40) |
Note: All models account for nested family structure of both samples.
Unstandardized regression coefficients presented with accompanying 95% confidence intervals presented in parentheses.
Models estimated using the MIDUS data include the following covariates: diet to control weight; smoked cigarettes in the past week; daily stressful experiences; verbal ability (BTACT); age; sex; and race. Models estimated using the Add Health data include the following covariates: physical activity in the past week; fast food consumption in the past week; smoked cigarettes in the past week; daily stressful experiences (perceived stress scale); verbal ability (Picture Vocabulary Test); age; sex; and race.
Missing values were handled using full information maximum likelihood (FIML) estimation for all estimated multivariate models.
Between-family effects provide an estimation of the association between adverse childhood experiences (ACEs) and each outcome across families. Within-family effects reflect differences in the same association between siblings from the same family.
A significant multiplicative interaction term between zygosity and the within-family effect would provide evidence of genetic confounding, while a nonsignificant interaction term would provide evidence of familial confounding.
Model estimated using a multilevel linear regression model.
Model estimated using a multilevel logistic regression model.
Model estimated using multilevel negative binomial regression model.
Model estimated using a multilevel linear regression model for the MIDUS sample and a multilevel negative binomial model for the Add Health sample.
p < .05;
p < .001