I know there's a correlation between weight training and increase in testosterone, but I'd never experienced it until I actually started lifting weights in earnest. I tend to be on the angry side, but it has always seemed like passive anger. Now I feel more aggressive. It's the difference between wishing I could stab someone in the face and actually thinking I could do it.
I've been reading Final Truth: The Autobiography of a Serial Killer and although it doesn't mention that Donald "Pee Wee" Gaskins did any weight training, he was a pretty aggressive fellow. What I find most disturbing about the book is the blandness of it all. Gaskins' account of his murders is done in a plain, straightforward way. Also, his language is blunt and cartoonishly rednecky in support of completely irrational thought. You get this sort of "she was a bitch, so I killed her" vibe with little to no explanation other than that he suffers from what he calls a "bothersomeness" which eventually bubbles up into uncontrollable, murderous rage. I guess we're so inundated with psycho-babble in regards to this ilk of horror that the absence of analysis leaves a massive, eerie hole in the reader's vision of the story. It can't be that simple, can it? I got angry, so I butchered her? Apparently, for the truly insane, it is.