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.     
If you’re taking mucuna capsules it would be better to take them half an hour before a protein shake. If you’re using the powder, in theory it would be better to have before as well, but to be honest, for the convenience and to disguise the taste I think you’d have more compliance by taking it in the shake. Realistically, having protein every 3 hours there’s unlikely to be a time when you system isn’t processing amino acids, except perhaps first thing in the morning. This is actually the best time to take mucuna so I’d take it then.
I live in Australia which has low selenium in it’s soil and i grew up on a farm in a time when imported or all year round fresh fruit and vegetables were rare. This coupled with the fact that we were relatively poor meant both my parents saw fruit as a luxury and vegetables as only those few we could grow in a low water area, so any selenium i might have accessed thru these sources was non existent. As a result I have suffered for years from chronic mental health problems. I have been diagnosed with everything from bipolar disorder to schizoaffective disorder to depression as well as trying to self medicating with various drugs both legal and illegal. There was three children in my family. I am, in my opinion, the only survivor. My brother killed himself at 39 yrs old and my sister has a 25 year chronic drug addiction and very questionable health. I learned about selenium 23 yrs ago and have experienced freedom from mental health problems and the nasty drugs they feed you ever since.
Thank you for your research it proves my subjective experience,