To be fair, all of these studies only look at the relationship between testosterone levels and aggressiveness in men.

There are other neurobiological factors that mediate the affect testosterone has on aggression. As a consequence, testosterone affects women differently. There are also other hormones that influence aggression levels. I believe this was examined in some mammal where you see more aggressive females despite lower levels of testosterone and despite a correlation between testosterone and aggressiveness in the males.

This is not to say that there is no biological basis for this difference in observed behavior. However, what is clear is that socialization plays a major part. And studies of correlations between testosterone and aggressiveness in men only are irrelevant to this discussion.