Familial sinistrality and sex differences in cognitive abilities.

The performance of right-handed males and females, with and without a family history of sinistrality (FS+ and FS-, respectively) were examined for three cognitive abilities: spatial ability, verbal fluency, and perceptual speed. FS+ subjects, especially females, showed performance decrements in spatial ability. Also, FS+ subjects, especially males, showed performance decrements in perceptual speed, with no differences being observed in verbal fluency.