Population differences in androgen levels: A test of the Differential K theory

•Differential-K theory tested using Androgen proxies.•Proxies were CAG length, androgenic hair, sex frequency, sex partners, prostate cancer.•7/10 proxy inter-correlations significant in predicted direction•On 5/5 proxies, East Asians have lower androgen than Caucasians.

Differential-K theory proposes that levels of androgen, i.e. male hormone, differ across three large racial groups with Sub-Saharan Africans having the highest levels, East Asians the lowest, and Caucasians (Europeans, North Africans and South Asians) being intermediate. In this study, we found that most of the national-level indicators of androgen – CAG repeats on the AR gene, androgenic hair, prostate cancer incidence, sex frequency and number of sex partners – are positively correlated at the population (country) level. East Asians showed signs of the lowest androgen level for most indicators and were lower than Caucasians on all of them. Sub-Saharan Africans showed inconsistent results. The results provide a partial validation of Differential-K theory.