Correlation between handedness and birth order: compilation of five studies.

Bakan has suggested that left-handedness is the result of left hemishperic pyramidal motor dysfunction following perinatal hypoxia. To a degree support for the validity of this hypothesis rests on Bakan's (1971, 1977a) findings that left-handed college students were more likely the progeny of birth orders designated as "high-risk" than right-handed students. Attempts by others to replicate Bakan's data have been unsuccessful. To achieve a more powerful test of this relationship than has been provided by any single study, the data from the five studies which have considered it were pooled and tested. The resulting correlation between birth order and handedness was near zero.