Table 2.
Correlations within MZ and DZ Twin Pairs and Univariate Heritability of Age 17 Adolescent Alcohol Consumption Index and Age 29 Adult Outcomes
| Adolescent Measures | MZ | DZ | A | C | E |
|---|---|---|---|---|---|
| Adolescent Alcohol Consumption Index (“ACI”) | .72(.69, .75) | .55(.48, .60) | .34(.22, .48) | .38(.24, .49) | .28(.25, .31) |
| Age 29 Measures | |||||
|
| |||||
| Substance Use and Substance Use | |||||
| Largest # Drinks Consumed | .51(.45, .56) | .29(.21, .37) | .43(.24, .56) | .08(.00, .24) | .49(.44, .55) |
| Avg # Drinks Consumed | .50(.45, .55) | .29(.21, .37) | .42(.23, .55) | .08(.00, .25) | .50(.45, .55) |
| Drug Classes Tried | .53(.48, .58) | .24(.15, .33) | .53(.42, .58) | .00(.00, .13) | .47(.42, .52) |
| Recent Marijuana Uses | .50(.45, .55) | .28(.20, .36) | .44(.25, .55) | .06(.00, .22) | .50(.45, .55) |
| Nicotine Dependence SX | .53(.47, .57) | .32(.24, .40) | .40(.23, .57) | .12(.00, .28) | .48(.43, .53) |
| Alcohol Use Disorder SX | .24(.17, .30) | .17(.08, .26) | .13(.00, .30) | .11(.00, .26) | .76(.70, .83) |
| Marijuana Use Disorder SX | .48(.42, .53) | .24(.16, .31) | .48(.29, .53) | .00(.00, .15) | .52 (.47, .58) |
| Antisocial Behavior and Legal Problems | |||||
| Adult Antisocial Behavior SX | .37(.31, .43) | .19(.10, .28) | .36(.15, .43) | .01(.00, .19) | .63(.57, .69) |
| Legal Problems | .23(.16, .29) | .03(.00, .13) | .21(.10, .27) | .00(.00, .09) | .79(.73, .85) |
| Socioeconomic Status | |||||
| Educational Stagnation | .69(.66, .73) | .56(.50, .62) | .26(.14, .40) | .43(.30, .54) | .31(.27, .34) |
| Occupational Stagnation | .49(.43, .55) | .15(.05, .24) | .48(.42, .53) | .00(.00, .08) | .52(.47, .58) |
| Financial Problems | .23(.16, .30) | .29(.20, .37) | .00(.00, .13) | .25(.20, .31) | .75(.69, .80) |
| Mental Health and Personality | |||||
| Major Depressive SX | .23(.16, .30) | .11(.03, .20) | .23(.11, .30) | .00(.00, .18) | .77(.70, .82) |
| Negative Emotionality | .44(.38, .50) | .19(.10, .28) | .44(.28, .49) | .00(.00, .14) | .56(.51, .62) |
| Behavioral Disinhibition | .50(.45, .55) | .15(.06, .24) | .49(.43, .54) | .00(.00, .07) | .51(.46, .57) |
| Social Functioning | |||||
| Antisocial Peers | .50(.45, .55) | .27(.18, .35) | .47(.28, .55) | .03(.00, .20) | .50(.45, .55) |
| Prosocial Peer Disaffiliation | .39(.33, .45) | .24(.14, .33) | .32(.10, .45) | .08(.00, .26) | .60(.55, .67) |
| Recent Sexual Partners | .39(.32, .45) | .25(.16, .33) | .29(.08, .45) | .10(.00, .28) | .61(.55, .68) |
| Partner’s Alcohol Misuse | .30(.21, .37) | .17(.04, .29) | .25(.00, .37) | .05(.00, .29) | .70(.63, .79) |
| Partner’s Permissiveness Toward Substance Use | .41(.33, .48) | .25(.13, .36) | .32(.08, .48) | .09(.00, .32) | .59(.52, .67) |
Note. The 95% confidence intervals of the correlations and variance component estimates are shown in parentheses. A = additive genetic influences; C = shared environmental influences; E = non-shared environmental influences.