Moshe Hoffman: UCSD Rady School of Management

We review the evidence regarding a biological basis for sex differences in risk aversion and competitiveness. We present the relevant literature in evolutionary theory, and animal behavior, endocrinology and neuroscience, as well as the literature relating human risk aversion and competitiveness to handedness, 2D:4D (a proxy of prenatal testosterone exposure), facial masculinity (a proxy of pubertal testosterone exposure), as well as circulating testosterone. While the results are thus far somewhat mixed, the evidence suggests that biological factors explain part of the sex gap in these economic preferences.
http://bec.ucla.edu/papers/HoffmanPaper1.pdf