Participant characteristics
| Characteristic | Group | ||||||
|---|---|---|---|---|---|---|---|
| XX | XY | XXX | XXY | XYY | XXYY | XXXXY | |
| Sample size age (years) | 80 | 89 | 28 | 58 | 26 | 20 | 5 |
| Mean | 12.8 | 12.8 | 12.3 | 12.8 | 12.4 | 14.1 | 12.9 |
| SD | 5.07 | 4.61 | 5.68 | 4.93 | 4.91 | 5.45 | 4.82 |
| Range | 5–25 | 5–25 | 5–24 | 5–25 | 5–23 | 5–22 | 7–17 |
| IQ* | |||||||
| Full-scale mean (SD) | 115 (14.1) | 116 (14.6) | 93 (13.5) | 97 (17.8) | 91 (14.6) | 87 (12.3) | 56 (7.2) |
| Verbal mean (SD) | 115 (14.8) | 113 (15.8) | 93 (14.1) | 95 (17.5) | 89 (14.1) | 81 (11.9) | 61 (9.8) |
| Performance mean (SD) | 111 (12.3) | 114 (14.3) | 94 (13.7) | 99 (17.8) | 95 (17.4) | 95 (11.5) | 56 (2.6) |
| Handedness | |||||||
| Right | 69 | 80 | 22 | 46 | 21 | 18 | 3 |
| Mixed | 5 | 6 | 4 | 7 | 1 | 1 | 1 |
| Left | 6 | 3 | 2 | 5 | 4 | 1 | 1 |
| SES* | |||||||
| Mean (SD) | 47 | 48 | 41 | 55 | 59 | 46 | 69 |
SES, socioeconomic status.
↵* p < 0.01 for omnibus test of significant variation across groups.