Journal of Risk and Uncertainty

, Volume 42, Issue 1, pp 1–26 | Cite as

Digit ratios (2D:4D) as predictors of risky decision making for both sexes

  • Ellen Garbarino
  • Robert SlonimEmail author
  • Justin Sydnor


Many important decisions involve financial risk, and substantial evidence suggests that women tend to be more risk averse than men. We explore a potential biological basis of risk-taking variation within and between the sexes by studying how the ratio between the length of the second and fourth fingers (2D:4D) predicts risk-taking. A smaller 2D:4D ratio has been linked to higher exposure to prenatal testosterone relative to estradiol, with men having lower ratios than women. In financially motivated decision-making tasks, we find that men and women with smaller 2D:4D ratios chose significantly riskier options. We further find that the ratio partially explains the variation in risk-taking between the sexes. Moreover, for men and women at the extremes of the digit-ratio distribution the difference in risk-taking disappears. Thus, the 2D:4D ratio partially explains variation in financial risk-taking behavior within and between sexes and offers evidence of a biological basis for risk-taking behavior.


Risk Sex differences Experiments Testosterone 

JEL Classification

C9 D81 



We thank Rachel Croson, John Manning, numerous seminar participants, an anonymous referee and the Journal of Risk and Uncertainty Editorial Board for useful comments on this project. Special thanks to Angelo Benedetti and Jason Cairns for invaluable research assistance. This project was supported by a grant from the Kauffman Foundation.


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Department of Marketing, Faculty of Economics and BusinessUniversity of SydneySydneyAustralia
  2. 2.School of Economics, Faculty of Arts and Social SciencesUniversity of SydneySydneyAustralia
  3. 3.Actuarial Science, Risk Management, and Insurance Department, Wisconsin School of BusinessUniversity of WisconsinMadisonUSA

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