We need a personality overhaul

I agree. Traits are so weak that they are totally devoured by emotions. Sims with different traits don't even act differently when different emotions are activated! An Evil sim should be doing evil things whether they're Angry, Happy, or Playful...and maybe be strangely nice when Sad. Hot-Headed sims should get snappy when they're Sad and be easily snapped out of a Happy mood into and Angry one by things like the computer breaking in the middle of a gaming session or the toilet going kaput when they flush it. Gloomy sims should take way more Happy influences to get Happy than most other sims. But, no. All sims are nearly identical with emotions and behavior...aside from trait-based emotions that get boosted by Happy.

Really, the Happy emotion is the scourge of this game. It's to easy to build up, it blocks negative emotions too easily, and (unless you have a mod to fix it) your sim will be perma-happy in any indoor space that isn't a barren concrete box.

...Thanks...I hate it...