First, Even if testosterone plays a role in male incarceration rates, your conjecture that a 15% increase in average testosterone can explain the severe racial disparity in incarceration rates in unsubstantiated. Even if "X causes Y", it does not follow that "15% more X causes xx% more Y".

Second, there are tons of alternative explanations (e.g. socialization). Nature vs. nurture is adolescent-level stuff, and obviously males and females are socialized differently. Stop being thick.

Third, that's not how science (or anything except religion) works. You don't get to make fallaciously substantiated conjectures and then demand everyone believe them until the core claim is disproven.

edit: Oh wow, based on prior coments you're actually just straight up early 20th century style racist, or a troll, or both. Done engaging you, and really hoping you're just a stupid troll and don't believe anything you're saying here.