The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression".   Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible.  The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game.  Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.     
Hey Ali, what did you do during the period where you were 17-18 to optimize your hormone production? I’m seventeen and I feel like a late bloomer. I’m pretty thin, at 138 lbs, I’m a 5’8 African American, and my shoulders are about 41 inches around. I want to optimize my hormones in order to hit the maximum height for my genetic potential, grower bigger everywhere, develop a more masculine face ( chisleled jawline, wide jaw, course features, etc). Do you have your personal journal in the form of an article anywhere on the site (Kind of new to the site)? Also, I start a strength program. I’m lifting with my schools football team for 30 mins before soccer practice, but soon I will have a gym membership and do starting strength or Greyskull LP.