There is evidence that the ratio of the length of the 2nd and 4th digit (2D:4D) is negatively related to prenatal and adult concentrations of testosterone. It has also been reported that high levels of testosterone at conception in both fathers and mothers are associated with an increased sex ratio (proportion of males at birth). It follows from these observations that low values of 2D:4D may b...

Proportions between pairs of digits are linked to fitness in tetrapods and they can be influenced by sex hormones through individuals’ ontogenies. Therefore, many species, the proportions amongst finger length ratios (referred as digit ratio, i.e. 2D second 4D fourth digits) differ males females. We investigated whether three most commonly used forelimb sexually dimorphic tropidurid species. In...

Sex and sex hormones play a major role in lung physiology. It has been proposed that the ratio of the second to fourth digits (digit ratio) is correlated with fetal sex hormones. We therefore hypothesized that digit ratio might help predict lung function. We investigated the relationship between digit ratio and pulmonary function test (PFT) findings. A total of 245 South Korean patients (162 ma...