Testosterone and hand performance in right-handed young adults.

The relationship between serum testosterone level and hand performance was studied in right-handed young adults without familial sinistrality. Hand performance was measured by a dot-filling task, which was found to be associated with serum testosterone depending upon sex. In women, the right- and left-hand performance was found to be negatively linearly related to testosterone; there was no significant correlation between the right- minus left-hand performance and testosterone. In men, right- and left-hand performance were found to be directly and inversely related to testosterone, respectively. This pattern exhibited some variations depending on eye and foot preferences. The difference in performance between hands was found to be positively linearly related to serum testosterone levels in men.