J.P. Rushton argued East Asians have the least testosterone, Blacks have the most and Caucasoids are in between.  However this claim has been challenged in recent years by East Asians who didn’t want to have less T than whites and whites who didn’t want less T than blacks.  Even though Rushton saw high T and sexual potency as primitive traits, millions of young men equate sex with self-worth and so their fragile egos can’t handle a low T racial stigma.

People really need to get a life.

I don’t have time to review all the research folks have done so I just did a quick search and found this graph:

testosterone

It seems that among single graduate students, Rushton’s hierarchy is confirmed, with Blacks enjoying more T than whites who have more T than East Asians.

However among grad students in relationships,  East Asians tower in T.  Perhaps that’s just an artifact of the small sample size of those in relationships, or perhaps because of anti-Asian discrimination by women, only the most hyper-masculine Asians are able to date (on average).  The theory implied by the study authors is that being in a relationship increases T for East Asians, but lowers it for non-Asian men.

But if testosterone levels can fluctuate that much just from being in a relationship, it sounds like too unstable a variable to be of much relevance to racial differences.

Perhaps a more interesting trait is 2D:4D ratio– Length of your second digit compared to your fourth digit.  The higher the ratio, the higher your femininity (on average) because you were prenatally bathed in more estrogen than testosterone.  In contrast, low 2D:4D ratio suggests more prenatal T exposure relative to estrogen, and thus more masculinity.

2d4d

According to this blog post,  low 2D:4D ratios predict aggression, fatherhood, early marriage, promiscuity, athleticism, risk taking, alcoholism, autism, spatial ability, ADHD, facial masculinity, penis length and prostate cancer.

It may also predict muscle mass.

High 2D:4D ratios predict smoking, obesity and verbal fluency.

Some of these correlations support theories I have proposed or endorsed.  Others may challenge those theories.

How does this fit with Rushton’s theory?  The Inductivist Blog claims:

It turns out that there are large ethnic differences in the 2D:4D ratio…According to the results of one study, “The Oriental Han had the highest mean 2D:4D, followed by the Caucasian Berbers and Uygurs, with the lowest mean ratios found in the Afro-Caribbean Jamaicans.” In plainer language, Hans were the most feminized and Jamaicans the most masculine.

I don’t have time to vet all these claims.  Some of the research might be old and may be overturned by newer larger studies, and even the true correlations might be small or non-causal.