HANDEDNESS IN BLOOD-DONORS - NO ASSOCIATION WITH BLOOD-GROUP OR TWINNING

There has been considerable interest in the contribution of inheritanc e to determination of handedness and in observed associations between hand laterality and twinning, gender and age. Unpublished data from a study of children born preterm suggested an association between ABO bl ood group and handedness. A questionnaire filled in by 3815 blood dono rs,gave information on blood group, age, gender, whether they were a t win, hand used for writing and perceived handedness. There was no asso ciation between ABO blood group or rhesus group and handednes. Signifi cantly more females than males considered themselves right handed (82. 5% versus 79.9%) and more subjects aged 50 + wrote with the right hand (90.6% versus 87.6% if younger). Twins did not differ from other subj ects in this study and we hypothesise that the generally inconsistent findings relating to twins may be explained by population differences in the proportion of twins born preterm.