For example, a Sim that feels flirty might prefer to keep on flirting, while an evil Sim would be less likely to tell a lot of jokes. Sims' autonomous behavior will also be more influenced by their mood or their traits.
Raise your hand if you like to cause as much drama in your Sims' lives as possible! Where's the fun in just watching your Sims go about their day in a normal, pleasant way? Sims should always be getting into arguments and pulling pranks on others, or else what's the point? This mod from FlorianPTME on Mod The Sims tries to nudge Sims into more conflict rather than shy away from it with their autonomous actions, as they tend to do in the game.