Perinatal factors in hand and eye preference: data from the Collaborative Perinatal Project.

Data from 5,899 girls and boys who participated in the NIH Collaborative Perinatal Project were analyzed for relationships between birth order and birth stress and hand and eye preference as measured at age seven. None of the birth variables were significantly related to hand preference at the 0.05 level for either boys or girls. However, left eye preference was related to birth stress in boys. When both sexes were combined, left eye preference was also associated with low and high birthweight, and also with right lateral position of the head in the maternal pelvis.