Testosterone and Dominance in Men

This paper serves as a good introduction to the relevant literature, and offers a possible explanation for what black-white T differences may exist in the US (*):


Nisbett (1993; Nisbett and Cohen 1996) has attributed the historically high violence in the American South, compared to the North, to its "culture of honor" whereby Southern men, when challenged by insults to themselves or their families, are required to defend themselves as virtuous warriors or else lose face. Apparently as a result, Southern men are unusually alert to possible insults, reacting dominantly -- sometimes violently -- to speech or actions that might not be perceived as injurious in other cultures.

Leaving aside the particular historic roots of the South, there may be a general hypersensitivity to insult in any subculture that is (or once was) organized around young men who are unconstrained by traditional community agents of social control, as often occurs in frontier communities, gangs, among vagabonds or bohemians, and after breakdowns in the social fabric following wars or natural disasters. When young men place special emphasis on protecting their reputations, and they are not restrained from doing so, dominance contests become ubiquitous, the hallmark of male-to-male interaction (Thrasher 1963, Sanchez-Jankowsky 1991).

The leading student of street behavior in America's inner cities, sociologist Elijah Anderson (1994), vividly portrays the importance of dominance contests and their constant presence for poor young black men:

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We know from laboratory and athletic studies that T rises in men awaiting a contest, regardless of the eventual outcome of that contest. Generalizing to the street, hormone levels should be elevated in young men who are constantly vigilant against assaults on their reputations. Of course, T is also affected by the outcome of the contest, so persistent losers might be hormonally depressed, but most men -- those with mixed outcomes or better -- should have elevated T.

A caveat: Stressors such as weight loss, surgery, or military training sometimes depress T (Kreuz et al. 1972; Strauss et al. 1985; Booth et al. 1993). If all stressors depressed T, then the stressful challenges of inner-city street life should lower the hormone, not elevate it. However, not all stressors are the same, and social challenges in particular evoke hormonal responses different from those due to surgery or weight loss. Indeed, we have already seen that T reliably rises in the face of competitive challenges, even while cortisol (the "stress hormone") goes up as well (Booth et al. 1989; Elias 1981; Salvador et al. 1987; Gladue et al. 1989). Thus, stress effects do not negate the hypothesis that street challenges elevate male T.

We may use this hypothesis to interpret reported racial differences in T. A comparison of black and white boys aged 6 to 18 years, mostly preteens, showed no significant race difference in T (Richards et al. 1992). By adulthood, black males do have significantly higher T levels than white males (Ross et al. 1986; Ellis and Nyborg 1992), possibly reflecting the higher defensive demands on black men during young adulthood.

The data set used by Ellis and Nyborg (1992) came from 4,462 army veterans, ranging in age from 30 to 47, and permits a finer grain analysis (Mazur 1995). Among veterans older than the median age of 37 years -- too old to be involved in inner-city honor cultures -- the T of blacks is no higher than that of whites. Furthermore, among younger veterans who have gone to college -- and thus are unlikely to be inner-city residents -- there is no significant race difference in T. Only among younger veterans with little education do we find T in blacks to be unusually high, significantly higher than in whites. These younger black men, poorly educated, most of them urban residents, are most likely to participate in the honor subculture, and that may be the reason for their elevated T.

The reciprocal linkage between hormones and behavior suggests that if T levels among young men in the inner city are heightened by their constant defensive posture against challenge, then these high hormone levels in turn encourage further dominance contests. Feedback between challenge and T may create a vicious circle, sometimes with lethal effects.

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A basal model is usually used in describing the causal effects of T on behavior, meaning that each man's T measurements represent short-term fluctuations around his characteristic basal level, which is genetically based, and that by adolescence or shortly afterward, this basal level is more or less consistent from year to year. Consistent with this model, reliabilities from r = .50 to .65 are reported for T measurements taken (at the same time of day to control for circadian variation) over periods ranging from days to six years (Booth and Dabbs 1993), showing that men with relatively high T at one time tend to be relatively high at other times too. On the assumption that basal hormone levels are consistent, they necessarily predate any post-adolescent behavior and so cannot be a consequence of that behavior. Furthermore, since basal levels are stable, it follows that they can be adequately measured at any time, whether before or after the behavior, and therefore can be adequately assessed in a cross-sectional study. Going further, basal hormone level is regarded as a prima facie cause of any post-adolescent behavior that it predicts, especially if the effect persists after controlling for alternate explanations.

We contrast the static basal model with a dynamic reciprocal model in which T and status competition influence one another, going up or down together. The observed reliability of a man's T measurements from year to year may reflect his stable social position rather than his genetically determined basal level. Current data are insufficient to choose one model over the other, so we regard both as viable and heuristically useful.

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The reliable association of high T with antisocial behaviors, including marital disruption and violent criminality, raises an interesting puzzle. These negative behaviors foster downward social mobility. Under the basal model, which assumes T level to be a persistent trait, we should expect an accumulation of high T men in the lower ranks of society. Indeed, as we have noted, correlations between T and various measures of socioeconomic status (occupation, income, education) are significantly negative. But they are slight in magnitude. Thus, leaving aside honor subcultures, we find little concentration of men with high T in the lower classes. Why not? One possibility is that the downward flow of high T men who are antisocial is nearly balanced by an upward flow of high T men who are prosocial. This hypothetical stream of prosocial high-T men remains invisible to us, so far, perhaps because past studies have used as subjects mostly working class men or convicts, who have limited opportunities for legitimate advancement.

The nearly uniform distribution of T across social classes is less puzzling under the reciprocal model, which regards T as malleable rather than a stable personality trait. Again excepting honor subcultures, where challenges are exceptionally common, dominance contests probably occur nearly as frequently among elites as in the working class, as often in the boardroom as on the shop floor. Therefore, T responses to challenge, and to winning and losing, should be distributed fairly evenly across classes. Under this reciprocal model, we would expect little accumulation of T at the bottom levels of society.

The applicability of one model or the other would be elucidated by studying the relationship of T to behavior among upper class men who have favorable social opportunities and strong incentives for prosocial behavior.

(*) A more recent study shows higher T levels in Hispanics (not quite in keeping with Rushton's rule) with little black-white difference, as well as higher estrogen levels in blacks than whites [1]. And, as noted previously, Africans in Africa evidently have lower T than whites. Given these facts, I find Mazur's "honor subcultures" hypothesis entirely plausible.

[1] J Clin Endocrinol Metab. 2007 Jul;92(7):2519-25. Epub 2007 Apr 24. Serum estrogen, but not testosterone, levels differ between black and white men in a nationally representative sample of Americans. Rohrmann S, Nelson WG, Rifai N, Brown TR, Dobs A, Kanarek N, Yager JD, Platz EA. http://jcem.endojournals.org/cgi/rapidpdf/jc.2007-0028v1.pdf

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