Table 2.
Probandwise twin concordances and number of affected individuals (probands) for high mathematical ability at 85% cut-offs organized by gender and zygosity for the three measures and the composite
| Variable | MZ m | DZ m | MZ f | DZ f | DZ opp |
|---|---|---|---|---|---|
| Understanding number | 48% n = 120 |
31% n = 124 |
49% n = 143 |
35% n = 119 |
34% n = 248 |
| Non-numerical processes | 42% n = 128 |
42% n = 130 |
39% n = 139 |
40% n = 115 |
35% n = 239 |
| Computation and knowledge | 46% n = 135 |
30% n = 121 |
44% n = 131 |
38% n = 125 |
31% n = 239 |
| Composite | 59% n = 123 |
40% n = 144 |
58% n = 135 |
44% n = 117 |
37% n = 239 |
Note: All extremes analyses were calculated on age-, but not sex—regressed scores