Part of the problem here is that even if testosterone had absolutely no effect on aggression at all, we would still see people taking testosterone injections acting more aggressive. Why? Because the common belief is that testosterone will make you more aggressive. Give them saline and tell them it's testosterone and they'll start bumping people in the street as well.
To test whether there is an actual effect going on here, they'd need to look at what how two different groups of FtM transsexuals respond when one is placed on a placebo, and one given testosterone. The article linked to by Gwern discusses this effect of perception on behavior:
Folk wisdom holds that testosterone causes antisocial, egoistic, or even aggressive behaviors in humans. However, the correlational studies discussed above already suggest that this simple folk view probably requires revision [34,56]. A recent placebo-controlled testosterone administration study found support for the idea that the testosterone–aggression link might be based upon ‘folk’ views: individuals given placebo who believed they had been given testosterone showed less fair bargaining offers compared with those who believed that they had received placebo, thus confirming people’s stereotypes about the behavioral effects of testosterone. More importantly, however, when statistically controlling for this belief of treatment assignment, one acute dose of testosterone in women increased the fairness of proposers’ bargaining offers in an ultimatum game [13] (Figure 3).
We’ve discussed signaling and status endlessly on LW; I think this is right up our vein: a 2011 review of research on the connections between famous male hormone testosterone and various forms of social interaction and especially social status, Eisenegger et al’s “The role of testosterone in social interaction”. (I grabbed this PDF in the short time Elsevier left full-text available, but only now, with some modafinil-powered spare time, have gotten around to excerpting it for you guys.)
1 Abstract
2 Excerpts
Is testosterone simply aggression promoting (a sort of ‘roid rage’)?
Probably not:
This may come as a surprise:
The null findings may be due to a possible confounding effect of homeostasis, but that wouldn’t cover the null on acute administration:
‘Dominant’ looks like a better perspective than ‘aggressive’:
This interest in dominance leads to mental changes (I am reminded of self-deception):
(The jokes about women and men almost make themselves.)
Not all of these changes are what one would naively expect (see previously about the ‘folk theory’ of testosterone):
I found interesting the material starting page 267, “Neurobiological mechanisms underlying the role of testosterone in social status hierarchies” (due to my own musings about the possible effects of masturbation went that it might be misinterpreted as reproductive ‘success’ which reduces risk-taking or activity in general):
Fear & stress:
Motivation & learning:
Summary of foregoing:
3 References