Abstract
Prenatal androgen exposure affects the brain development of the fetus which may
facilitate certain behaviors and decision patterns in the later life. The ratio between the
lengths of second and the fourth fingers (2D:4D) is a negative biomarker of the ratio
between prenatal androgen and estrogen exposure and men typically have lower ratios
than women. In line with the typical findings suggesting that women are more risk averse
than men, several studies have also shown negative relationships between 2D:4D and
risk taking although the evidence is not conclusive. Previous studies have also reported
that both men and women believe women are more risk averse than men. In the current
study, we re-test the relationship between 2D:4D and risk preferences in a German
student sample and also investigate whether the 2D:4D ratio is associated with people’s
perceptions about others’ risk preferences. Following an incentivized risk elicitation
task, we asked all participants their predictions about (i) others’ responses (without sex
specification), (ii) men’s responses, and (iii) women’s responses; then measured their
2D:4D ratios. In line with the previous findings, female participants in our sample were
more risk averse. While both men and women underestimated other participants’ (non
sex-specific) and women’s risky decisions on average, their predictions about men were
accurate. We also found evidence for the false consensus effect, as risky choices are
positively correlated with predictions about other participants’ risky choices. The 2D:4D
ratio was not directly associated either with risk preferences or the predictions of other
participants’ choices. An unexpected finding was that women with mid-range levels
of 2D:4D estimated significantly larger sex differences in participants’ decisions. This
finding needs further testing in future studies.