Blood and saliva samples were obtained from 117 healthy young men, following which radioimmunoassays were used to determine the serum concentrations of testosterone (T_ser), 5α-dihydrotestosterone (DHT), and the level of free testosterone (T_sal) in the saliva. The cognitive functioning was determined by five spatial and six verbal ipsative test scores, reflecting intra-individual variance in the performance of these tasks, independent of the person’s general level of achievement. Within the normal physiological range androgen levels – especially T_ser and to a lesser extent DHT and T_sal – showed a significantly positive correlation with measures of spatial ability and field dependence-independence and a significantly negative correlation with measures of verbal production.

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Differences in physical aggression among 114 male !Kung San (bushmen) from Namibia were investigated with regard to sex hormone levels, body dimensions, consumption of alcohol, and degree of acculturation. Subjects were classified from injuries resulting from prior conflicts with mutual physical aggression between the opponents as either violent or nonviolent. The comparison of mean sex hormone values (total serum testosterone, Tser; serum 5α‐dihydrotestosterone, DHT; serum estradiol 17β, E2; “free,” non‐SHBG‐bound salivary testosterone, Tsal) and hormone ratios (Tsal/Tser; DHT/Tser) did not yield any significant differences between the violent and nonviolent group. However, correlation coefficients of sex hormone levels with the frequency of violent behavior within the group of physically aggressive San men were significantly positive for DHT, Tsal, and Tsal/Tser (P < .05) while Tser, E2, and DHT/Tser showed only weak positive correlations. Moreover, the violent men exhibit higher mean values in certain measures of physical robustness which may point to a possible pathway of indirect androgen action on human aggression. When the probands were classified according to their drinking habits, usually abstinent men had shown significantly less violent behavior in the past than men who habitually consume alcohol.