system
A chat on subreddit /r/NoStupidQuestions
human
More testosterone = more aggressiveness. It's basic biology.
gpt
And, as is often the case, basic is wrong.

More testosterone doesn't make you more violent than you would otherwise have been. It makes you more *confident* in being violent towards the ones you were already violent towards.

Testosterone is an accelerant, not a cause. 

More testosterone is also associated with male pattern baldness. Are all bald men more violent than non bald men? 

Without the socialisation to excuse and encourage violent acts more testosterone does not automatically mean more aggressiveness.