Table 2.
Mean and Frequency Comparisons for Mastery and Alcohol Dependence Across Gender, Zygosity, and Gender by Zygosity Subgroups
| Variable | Women |
Men |
Difference by | ||||||
|---|---|---|---|---|---|---|---|---|---|
| MZ | DZ | OSDZ | MZ | DZ | OSDZ | ||||
|
|
|
||||||||
| M (SD) | M (SD) | M (SD) | M (SD) | M (SD) | M (SD) | Gender (Female) |
Zygosity (DZ twin) |
Oppositesex twin |
|
| Mastery | 17.07 (3.04) | 17.21 (3.35) | 17.55 (3.15) | 18.12 (3.00) | 17.82 (2.95) | 17.95 (3.00) | −0.62*** | −0.14 | 0.23* |
| Alcohol dependence %dependent |
8.4% | 8.0% | 12.6% | 23.0% | 27.2% | 26.4% | −1.08*** | 0.18* | 0.08 |
| Age | 36.82 (7.68) | 38.34 (8.08) | 36.88 (8.93) | 36.29 (9.13) | 38.31 (9.18) | 37.03 (8.96) | −0.01 | 1.67*** | −1.08*** |
| Education | 13.66 (2.00) | 13.42 (2.06) | 13.68 (2.33) | 13.66 (2.53) | 13.26 (2.81) | 13.62 (2.57) | 0.14* | −0.35*** | 0.29** |
| Self-esteem | 31.44 (4.48) | 31.59 (4.64) | 31.53 (4.82) | 32.92 (4.43) | 32.53 (4.33) | 32.32 (4.53) | −0.94*** | −0.21 | −0.18 |
| Optimism | 17.60 (2.79) | 17.58 (2.97) | 17.43 (2.85) | 18.01 (2.61) | 17.79 (2.63) | 17.80 (2.72) | −0.30*** | −0.12 | −0.10 |
| Neuroticism | 4.03 (3.18) | 4.05 (3.29) | 4.16 (3.25) | 2.80 (2.93) | 3.03 (3.07) | 3.25 (3.19) | 0.97*** | 0.16 | 0.20 |
MZ, monozygotic twins; DZ, same-sex dizygotic twins; OSDZ, opposite-sex dizygotic twins. Coefficients from generalized estimating equation (GEE) analyses show effects of gender (female), zygosity (DZ as compared toMZ twin), and gender of twin (opposite-sex compared with same-sex) on mastery and of % lifetime alcohol dependence. The analyses corrected for the nested structure of the data.
*
p < 0.05
**
p < 0.01
***
p < 0.001.