Table 2.
The total number of twin pairs within each age group that has been selected for the homogeneity analysis
| Age | MZ | DZ | Total | ||||
|---|---|---|---|---|---|---|---|
| Males | Females | Males | Females | Opposite-sex | MZ | DZ | |
| 18–19 | 298 (262) | 596 (552) | 230 (204) | 491 (431) | 355 (325) | 894 (814) | 1076 (960) |
| 20–21 | 219 (210) | 392 (369) | 160 (146) | 371 (336) | 238 (225) | 611 (579) | 769 (707) |
| 22–24 | 92 (86) | 173 (161) | 49 (44) | 123 (105) | 104 (97) | 265 (247) | 276 (246) |
| 25–34 | 77 (70) | 248 (229) | 46 (38) | 108 (94) | 114 (103) | 325 (299) | 268 (235) |
| 35–70 | 178 (163) | 512 (478) | 74 (66) | 174 (164) | 195 (188) | 690 (641) | 443 (418) |
| Agg | 981 (891) | 2165 (2004) | 645 (576) | 1525 (1349) | 1195 (1103) | 3146 (2895) | 3365 (3028) |
The number of twin pairs with a full data record (i.e., with data available for all 13 items in both twins) are in brackets
‘Agg’ denotes the data aggregated over age. If the twin members of the same pair have data in two separate age categories, this pair is omitted from the age grouping to enable multi-group analysis (which requires independent groups). However, this pair is not omitted from the interaction analysis in the aggregated data, leading to data in 6511 pairs for interaction analyses