Table 1.
Descriptive data of informants (mothers, fathers and twins), individual ratings by zygosity group
| Zygosity group | Informant | N | Mean | SD |
|---|---|---|---|---|
| MZ Males | Mother | 423 | 13.75 | 3.05 |
| Father | 314 | 13.57 | 2.75 | |
| Twins | 413 | 12.99 | 3.00 | |
| MZ Females | Mother | 576 | 13.53 | 3.16 |
| Father | 415 | 13.44 | 3.14 | |
| Twins | 595 | 12.62 | 3.47 | |
| DZ Males | Mother | 381 | 14.08 | 2.96 |
| Father | 288 | 13.58 | 3.16 | |
| Twins | 373 | 13.13 | 3.40 | |
| DZ Females | Mother | 456 | 13.60 | 3.20 |
| Father | 328 | 13.55 | 2.99 | |
| Twins | 477 | 12.51 | 3.27 | |
| DOS | Mother | 775 | 13.85 | 3.12 |
| Father | 581 | 13.38 | 2.96 | |
| Twins | 752 | 13.07 | 3.29 |
Note: MZ monozygotic, DZ dizygotic