Digit ratio and risk taking: evidence from a large, multi-ethnic sample

Using a large (n=543) multi-ethnic sample of laboratory subjects, we systematically investigate the link between the digit ratio (the ratio of the length of the index finger to the length of the ring finger, also called 2D:4D ratio) and two measures of individual risk taking: (i) risk preferences over lotteries with real monetary incentives and (ii) self-reported risk attitude. Previous studies have found that the digit ratio, a proxy for pre-natal testosterone exposure, correlates with risk taking in some subject samples, but not others. In our sample, we find, first, that the right-hand digit ratio is significantly associated with risk preferences: subjects with lower right-hand ratios tend to choose more risky lotteries. Second, the right-hand digit ratio is not associated with self-reported risk attitudes. Third, there is no statistically significant association between the left-hand digit ratio and either measure of individual risk taking.