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.     
Great article, well written and god conclusions of collected data.
How ever I am still curious if creating a “shortage” of sperm and decrease of testosterone by cycles of repeated ejaculations during a short period of time, maybe during the course of hours followed by “rest-days” if that over time would provoke the body to produce more Testosterone and sperm in a response to “progressive overload”.
Since this is the way the body handles a lot other things that challenges it´s system with everything from resistance-training, “repeated skin-abrasion”, bacteria and even some toxins.