Thank you for this. I also wish Sims had actual personality instead just traits. My loner sim doesn't act like a loner, he just gets a negative moodlet around other sims. When he's at a party or interacting he should be shying away and quieter instead of being just as lively and animated as the outgoing Sim talking to him.
In short, I wish their traits affected their behavior/body language/reactions to other Sims and events, as opposed to their emotional state. I wish a