The testosterone argument is a bullshit one in this context: the article you posted isn't trying to connect the dots in the disingenuous way you are, it's talking about
prostate cancer. It does not attempt to suss out whether or not testosterone levels are the cause of crime, period. The misstep you are taking is assuming that testosterone
causes crime, rather than
correlates with it. Even this article [1], which you will probably salivate over, doesn't suggest that testosterone
causes crime, merely that it correlates with misbehavior (in a very particular setting, namely prison). Here's [2] research that suggests that socioeconomic status mitigates the correlation between testosterone and misbehavior. At a minimum, this suggests that we have a chicken-egg dilemma between testosterone and misbehavior. The next question I would ask is: Do troubled settings and poor childhoods engender higher testosterone levels in adulthood?
Lastly, above and beyond any correlation between testosterone and crime, how do you propose to use this information to inform policy decisions? My main gripe in this fantasyland of HBD-speak is that people use this information as "scientific" grounds for enforcing their racist policy predispositions. I'd like to hear where you think you would take this testosterone point, but all too often people (and unfortunately, I get the impression that you are one of them) imply that these few studies are grounds for damning and castigating entire populations because of their perceived inferiority and incorrigibility.
[1] http://www.sciencedirect.com/science/article/pii/01918869940...
[2] http://pss.sagepub.com/content/1/3/209.short
EDIT for posterity: I would like to point out that you posted your cousin/uncle link upthread after I posted my GP comment above. I wouldn't have made as strong a comment had I seen links or sources.