Is It Biology?

(Photo: Ruth L)

(Photo: Ruth L)

A very nice new paper (IZA Discussion Paper 7575) by Anne Gielen, Jessica Holmes and Caitlin Myers asks whether testosterone, which generates masculine traits, contribute to male-female differences in labor-market outcomes.  The research innovation is to look at earnings differences between female twins, distinguishing those who had male twins (and thus were exposed to testosterone in utero) and those who had a twin sister (and thus were not exposed).  There are no significant differences in earnings; if anything, the female twins exposed to testosterone earned slightly less than women with a female twin.  Biology may matter; but this simple experiment should increase one’s belief that culture is more important.

steve cebalt

Being exposed to testosterone in utero is not the same as having testicles that produce testosterone constantly.


Well, the East Germans demonstrated pretty convincingly that testosterone was the primary driver of differences in physical performance. There are also a couple of recent studies showing that women with higher testosterone levels were more aggressive in investing and to some extent more successful.