Testosterone and Tendency to Engage in Self-Employment

Does testosterone increase the tendency to engage in self-employment? The results presented to date have been mixed. Using three different studies, we provide additional evidence on the relationship between testosterone and self-employment. Drawing on a cross-section of 2,146 individuals (1,178 males and 968 females) from the National Health and Nutrition Examination Surveys’ (NHANES’) 2011-2012 sample, and controlling for endogeneity (with red blood cell count, percentage Hematocrit, and zinc supplements intake in the past 30-days as instruments), serum testosterone levels are positively associated with self-employment for males (marginally significant, two-tailed test). As testosterone levels could be affected by social, economic, and biological factors during one’s life course, to draw more robust inferences we assess whether the 2D:4D digit ratio, a marker of prenatal testosterone exposure, influences the likelihood of self-employment. We reviewed a sample of 971 cases (449 males and 525 females) from Understanding Society’s Innovation Panel 6 (IP6), and our results indicate that males (females) with lower 2D:4D ratio in their left hand, or higher prenatal testosterone exposure, have a significantly greater (marginally significant for females) likelihood of self-employment (two-tailed test). Finally, we examine the twin testosterone transfer effect in a sample of opposite-sex and same-sex twins from the National Survey of Midlife Development (MIDUS I) in the Unites States and provide additional support for the marginally significant (two-tailed test) positive association between testosterone and self-employment.