Table 1.
Descriptive information of the samples.
| Australia | Canada | Denmark | Japan | Czech Republic | United States | |
|---|---|---|---|---|---|---|
| N | 866 | 900 | 1190 | 1286 | 709 | 1336 |
| Female | 502 | 587 | 603 | 846 | 415 | 657 |
| Age (M) | 22.47* | 33.66 | 38.14 | 20.85** | 36.03*** | 56.73 |
| Age (SD) | 3.73 | 13.87 | 11.52 | 3.9 | 14.02 | 14.8 |
| Age (range) | 17–33 | 15–68 | 18–67 | 14–30 | 15–81 | 19–89 |
| Identical MZ twin pairs | 193 | 249 | 232 | 449 | - | - |
| Same sex DZ twin pairs | 124 | 154 | 238 | 118 | - | - |
|
| ||||||
| Opposite sex DZ pairs | 116 | 47 | 125 | 76 | - | - |
NOTE: MZ = monozygotic; DZ = dizygotic;
*
For two individuals age at testing was not known;
**
For one twin pair age was unknown;
***
For 9 participants age was unknown.