Can I reset my characters' AI Personalities?

I recently started playing Divinity: Original Sin without really knowing what I was getting myself into. I didn't know what AI Personality did, so I kind of just picked something that sounded good.

However, after having to restart on an easier difficulty, I apparently set my second party member's AI Personality differently than the previous time, as their response to the same dialogue option in the same conversation the second time around was different and ended up influencing a non-beneficial stat for that character. I'd like to change their AI Personality, because the dialogue I've been hearing so far really doesn't suit the character I had in mind.

Is there a way for me to reassign my party members' AI Personality without starting the game over (again)?