Table 2.
Zygosity | Number of Twin Pairs | Tetrachoric Correlation | 95% CI |
---|---|---|---|
All | 617 | −0.01 | −.15 to .13 |
Monozygotic | 112 | 0.21 | −.10 to .50 |
Dizygotic | 505 | −0.07 | −.23 to .09 |
Monozygotic | 112 | 0.21 | −.10 to .50 |
SS Dizygotic | 262 | −0.10 | −.30 to .11 |
OS Dizygotic | 243 | −0.03 | −.28 to .22 |
Abbreviations: OS, opposite sex; SS, same sex.