I've thought a lot about Traits and I'm not so sure another trait slot would actually make a positive difference. Most traits just give buffs to emotions, and the problem with that is that all Sims are constantly shifting between the same moods from generic game buffs like needs, food, decorations, activities, etc so they are not distinctive and don't actually influence behavioral changes much at all. So I think changing the traits that we have to dictate behaviors, along with environmental tuning to neutralize mood buffs is more important.
Also, I've started an experiment with choosing fewer traits per Sim to see if personalities are more distinctive. I have a theory that since Sims 4 is more simplified than previous versions, that personalities might work better when simplified as well. Too many Traits might have the opposite effect from what we expect and actually muddle behaviors even more. We'll see how it turns out.
