| Left-handedness | Mixed-handedness | Non-right-handedness |
---|---|---|---|
Studies (k) | 43 | 10 | 47 |
 | 27 included in [10] | 5 included in [10] | 28 included in [10] |
 | 3 excluded from [10] | 5 new studies | 3 excluded from [10] |
 | 13 new studies |  | 16 new studies |
Individuals in total (n) | 63,295 | Â | Â |
Individuals per comparison (n) | 59,973 | 28,511 | 63,181 |
MZ twins (n) | 25,957 | 10,164 | 27,203 |
DZ twins (n) | 34,016 | 18,347 | 35,978 |
Prevalence in MZ twins | 11.45% (n = 2971) | 1.83% (n = 186) | 12.08% (n = 3286) |
Prevalence in DZ twins | 11.82% (n = 4019) | 3.26% (n = 599) | 13.29% (n = 4780) |
OR [95% CI] | 0.98 [0.89, 1.07] | 0.96 [0.46, 1.99] | 1.01 [0.91, 1.12] |
z | − 0.51 | − 0.11 | 0.13 |
Heterogeneity among studies | Q(42) = 74.08** | Q(9) = 100.52*** | Q(46) = 149.78*** |
 | I2 = 36.00% | I2 = 86.33% | I2 = 57.63% |
 | Tau2 = 0.02 | Tau2 = 0.88 | Tau2 = 0.05 |