Lydia had a stretch between 3.3 & 3.6 (or so) where she was so violent we thought there might be something wrong with her.
Fortunately it passed, as does much of their aggrevating behavior, and for the most part she's fine now. She can still throw the most amazing dramas. Almost 4 is bringing an ability to be reasoned with that we're enjoying. I'm hoping for a much better 4!