The distribution of the Geschwind scores to familial left-handedness.

The principal objective of this work was to study the influence of the familial sinistrality (FS) on the distribution of the hand preference in males and females. The hand preference was assessed by the Oldfield's questionaire. The distributions of the Geschwind scores were compared in the subjects without and with FS. The strong right-handedness was reduced; the strong left-handedness was accentuated under the influence of FS. This left shift in the hand preference presumably inherited by a left shift factor was more pronounced in males than females. It was tentatively suggested that the subjects with FS might be better in mathematics than the subjects with no FS.