Do risk and time preferences have biological roots?

We revisit the claims about the biological underpinnings of economic behavior by specifically exploring if observed gender differences in risk/time preferences can be explained by natural fluctuations in progesterone/estradiol levels during the menstrual cycle and by prenatal exposure to testosterone and estrogen levels. We find no effect of the menstrual cycle ( and thereby, of associated fluctuations in progesterone and estradiol levels) or of the digit ratio on either risk or time preferences.