Table 2 Number and percent of non-right-handers (NRH) and right handers (RH) by sample and sex for four handedness direction indicators
From: Prevalence and heritability of handedness in a Hong Kong Chinese twin and singleton sample
| Â | Twins | Singletons | Total | ||||||
|---|---|---|---|---|---|---|---|---|---|
Handedness Direction | Male n (%) | Female n (%) | χ2(df = 1) | Male n (%) | Female n (%) | χ2(df = 1) | Twins n (%) | Singletons n (%) | χ2(df = 1) |
Writing hand | |||||||||
 NRH | 17 (9.1%) | 14 (7.1%) | 0.51 | 19 (8.6%) | 14 (6.9%) | 0.46 | 31 (8.1%) | 33 (7.8%) | 0.02 |
 RH | 170 (90.9%) | 183 (92.9%) |  | 201 (91.4%) | 190 (93.1%) |  | 353 (91.9%) | 391 (92.2%) |  |
Drawing hand | |||||||||
 NRH | 26 (13.9%) | 21 (10.7%) | 0.94 | 27 (12.3%) | 29 (14.2%) | 0.35 | 47 (12.2%) | 56 (13.2%) | 0.17 |
 RH | 161 (86.1%) | 176 (89.3%) |  | 193 (87.7%) | 175 (85.8%) |  | 337 (87.8%) | 368 (86.8%) |  |
EHI2 | |||||||||
 NRH | 13 (7.0%) | 12 (6.1%) | 0.12 | 20 (9.1%) | 16 (7.8%) | 0.21 | 25 (6.5%) | 36 (8.5%) | 1.13 |
 RH | 174 (93.0%) | 185 (93.9%) |  | 200 (90.9%) | 188 (92.2%) |  | 359 (93.5%) | 388 (91.5%) |  |
PegQ2 | |||||||||
 NRH | 23 (12.1%) | 29 (14.2%) | 0.38 | 40 (18.1%) | 25 (12.2%) | 2.87 | 52 (13.2%) | 65 (15.3%) | 0.71 |
 RH | 167 (87.9%) | 175 (85.8%) |  | 181 (81.9%) | 180 (87.8%) |  | 342 (86.8%) | 361 (84.7%) |  |