Delay discounting is associated with the 2D:4D ratio in women but not men

The propensity to value a reward less as the delay to receive that reward increases is known as delay discounting and is typical of many forms of impulsive behavior. The current study investigated the relationship between delay discounting and the 2D:4D ratio, a proposed marker of prenatal androgen exposure, in 184 male and female college students. While male 2D:4D ratios were significantly lower than female ratios, there was no sex difference in delay discounting and no overall relationship between digit ratio and delay discounting. There was a significant negative correlation between the right 2D:4D ratio and delay discounting in women, with lower ratios associated with greater delay discounting. Results are discussed in terms of the adaptive value of impulsiveness in men and women and possible differences in sensitivity to the effects of prenatal versus circulating testosterone.