Another great article that I found. After reviewing all the temperaments I think my son most fits this one:
High intensity level temperament moves the child to yell, scream, or hit hard when feeling threatened.
As you can imagine it makes for a rather volatile environment. He yells a lot (thankfully more than he hits, but that does happen some times too). I'm constantly having to remind him not to holler at me or at his sister and others.