Table 1 Edinburgh Handedness Inventory data split by sample and sex
From: Prevalence and heritability of handedness in a Hong Kong Chinese twin and singleton sample
| Item | Preference | Twins | Singletons | Total | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Item | total | Male | Female | χ2(df = 2) | Male | Female | χ2(df = 2) | Twins | Singletons | χ2(df = 2) | |
| r | Class | N = 187 | N = 197 | N = 220 | N = 204 | N = 384 | N = 424 | ||||
| LH | 13 (7.0%) | 14 (7.1%) | 16 (7.3%) | 9 (4.4%) | 27 (7.0%) | 25 (5.9%) | |||||
| 1. Writing | .717 | NP | 4 (2.1%) | 0 (0.0%) | 4.26 | 3 (1.4%) | 5 (2.5%) | 2.17 | 4 (1.0%) | 8 (1.9%) | 1.37 |
| RH | 170 (90.9%) | 183 (92.9%) | 201 (91.4%) | 190 (93.1%) | 353 (91.9%) | 391 (92.2%) | |||||
| LH | 15 (8.0%) | 13 (6.6%) | 16 (7.3%) | 12 (5.9%) | 28 (7.3%) | 28 (6.6%) | |||||
| 2. Drawing | .718 | NP | 11 (5.9%) | 8 (4.1%) | 1.02 | 11 (5.0%) | 17 (8.3%) | 2.14 | 19 (4.9%) | 28 (6.6%) | 1.11 |
| RH | 161 (86.1%) | 176 (89.3%) | 193 (87.7%) | 175 (85.8%) | 337 (87.8%) | 368 (86.8%) | |||||
| LH | 16 (8.6%) | 20 (10.2%) | 30 (13.6%) | 13 (6.4%) | 36 (9.4%) | 43 (10.1%) | |||||
| 3. Throwing | .427 | NP | 65 (34.8%) | 69 (35.0%) | 0.32 | 99 (45.0%) | 83 (40.7%) | 8.99* | 134 (34.9%) | 182 (42.9%) | 6.49* |
| RH | 106 (56.7%) | 108 (54.8%) | 91 (41.4%) | 108 (52.9%) | 214 (55.7%) | 199 (46.9%) | |||||
| LH | 16 (8.6%) | 12 (6.1%) | 23 (10.5%) | 19 (9.3%) | 28 (7.3%) | 42 (9.9%) | |||||
| 4. Holding Scissors | .659 | NP | 25 (13.4%) | 18 (9.1%) | 2.86 | 43 (19.5%) | 20 (9.8%) | 8.57* | 43 (11.2%) | 63 (14.9%) | 4.66 |
| RH | 146 (78.1%) | 167 (84.8%) | 154 (70.0%) | 165 (80.9%) | 313 (81.5%) | 319 (75.2%) | |||||
| LH | 16 (8.6%) | 12 (6.1%) | 26 (11.8%) | 12 (5.9%) | 28 (7.3%) | 38 (9.0%) | |||||
| 5. Brushing Teeth | .585 | NP | 44 (23.5%) | 49 (24.9%) | 0.89 | 57 (25.9%) | 47 (23.0%) | 5.75 | 93 (24.2%) | 104 (24.5%) | 0.81 |
| RH | 127 (67.9%) | 136 (69.0%) | 137 (62.3%) | 145 (71.1%) | 263 (68.5%) | 282 (66.5%) | |||||
| LH | 11 (5.9%) | 14 (7.1%) | 20 (9.1%) | 14 (6.9%) | 25 (6.5%) | 34 (8.0%) | |||||
| 6. Chopsticks | .689 | NP | 8 (4.3%) | 2 (1.0%) | 4.19 | 9 (4.1%) | 8 (3.9%) | 0.73 | 10 (2.6%) | 17 (4.0%) | 2.01 |
| RH | 168 (89.8%) | 181 (91.9%) | 191 (86.8%) | 182 (89.2%) | 349 (90.9%) | 373 (88.0%) | |||||
| LH | 15 (8.4%) | 17 (9.0%) | 20 (9.1%) | 12 (5.9%) | 32 (8.7%) | 32 (7.5%) | |||||
| 7. Spoon | .559 | NP | 41 (23.0%) | 34 (18.1%) | 1.38 | 57 (25.9%) | 66 (32.4%) | 3.13 | 75 (20.5%) | 123 (29.0%) | 7.61* |
| RH | 122 (68.5%) | 137 (72.9%) | 143 (65.0%) | 126 (61.8%) | 259 (70.8%) | 269 (63.4%) | |||||
| LH | 17 (9.6%) | 18 (9.6%) | 26 (11.9%) | 32 (15.8%) | 4.53 | 35 (9.6%) | 58 (13.8%) | ||||
| 8. Knife without fork | .520 | NP | 24 (13.6%) | 14 (8.0%) | 3.02 | 45 (20.5%) | 27 (13.4%) | 39 (10.7%) | 72 (17.1%) | 11.57** | |
| RH | 136 (76.8%) | 155 (82.4%) | 148 (67.6%) | 143 (70.8%) | 291 (79.7%) | 291 (69.1%) | |||||
| LH | 30 (16.9%) | 26 (13.9%) | 40 (18.2%) | 30 (14.7%) | 56 (15.3%) | 70 (16.5%) | |||||
| 9. Broom | .362 | NP | 49 (27.5%) | 42 (22.5%) | 2.44 | 61 (27.7%) | 51 (25.0%) | 1.79 | 91 (24.9%) | 112 (26.4%) | 0.57 |
| (Upper hand) | RH | 99 (55.6%) | 119 (63.6%) | 119 (54.1%) | 123 (60.3%) | 218 (59.7%) | 242 (57.1%) | ||||
| LR | 11 (6.2%) | 20 (10.7%) | 20 (9.1%) | 21 (10.3%) | 31 (8.5%) | 41 (9.7%) | |||||
| 10. Opening a box lid | .410 | NP | 78 (43.8%) | 69 (36.9%) | 3.38 | 116 (52.7%) | 95 (46.6%) | 1.61 | 147 (40.3%) | 211 (49.8%) | 9.10* |
| RH | 89 (50.0%) | 98 (52.4%) | 84 (38.2%) | 88 (43.1%) | 187 (51.2%) | 172 (40.6%) | |||||