Gender differences in relations of mental rotation, verbal fluency, and SAT scores to finger length ratios as hormonal indexes.

One hundred thirty-four university students (93 women, 41 men) were administered the Vandenberg Mental Rotation Test and the Thurstone Word Fluency Test, and they were asked to report their Scholastic Achievement Test scores. Finger lengths were measured, because literature has reported gender differences in the ratio of the 2nd to 4th, 2nd to 3rd, and 2nd to 5th finger lengths, such that the ratio is larger in women than in men. The goal of this study was to evaluate the relations between finger-length ratios and cognitive skills, such as spatial skills and verbal fluency, which have shown gender differences and direct relations to hormonal effects. Gender differences were found in the expected directions, such that the men performed better than the women for mental rotation, the women performed better than the men for verbal fluency, and the finger-length ratios were in the directions reported in the literature. The finger-length ratios showed an interesting relation with the cognitive variables for the men and women. For the men, better performance on the measures, including mental rotation, verbal fluency, and verbal Scholastic Achievement Test score was associated with less of a male-typical finger-length ratio pattern, or higher ratios. For the women, better performance for mental rotation and verbal fluency was associated with less of a female-typical finger-length ratio pattern, or lower ratios. Thus, in this group of college students, better cognitive performance was associated with a less gender-typical finger-length ratio, for both men and women. These findings are discussed in the context of other similar reports and a possible curvilinear relation between hormones and cognition in normal populations.