A hard second to this. I would make a clear distinction between personality traits and actions.

This will mix subjects and I don't know enough to plant a flag on this hill let alone die on it, but imagine the moral serial killer who has urges to kill but never acts on them. They can't change who they are (as an adult as far as I know from current research), but they can try their best to affect actions. But their traits underneath are not changing.*

* Ignore the actual claims re serial killers, changing, and how that actually probably isn't personality traits, or maybe it is. Point being, it highlights a key difference between the state / biology of a person and how they act in the world.