@ehBeth,
How about this fellow's usual temperament, or unusual temperament?
I think the guy who screamed at me around my house, scary ****, was at heart a gentle person who'd spent much time on meth and had much investment in doing well on the job in the aftermath. He f/d up royally twice. The rage on being told about it in a mild way was not good.
I was lucky in that he didn't actually attack me, or maybe it wasn't luck, he was not naturally an attacker.
Which makes me wonder, do people who are not natural attackers in a tough world resort to meth for comfort? I get that meth probably starts as anything else does, play, let's try it.