The 2D:4D digit ratio, the ratio of the length of the 2nd digit to the length of the 4th digit, is often considered a proxy for testosterone exposure in utero. A recent study by Nicolaou et al. (2018) reported an association between the left-hand 2D:4D and self-employment (in a sample of about...

The digit ratio (2D:4D) is considered a proxy for testosterone exposure in utero, and there has been a recent surge of studies testing whether 2D:4D is associated with economic preferences. Although the results are not conclusive, previous studies have reported statistically significant...