Please make "smiling' a trait, not a default expression.

I recently posted about how I haven't properly played the game in 2 years, and how disturbing it was to be confronted by constantly smiling Sims.  I totally forget that was an almost default state of expression for them and man...it feels so unnatural to see constantly.

I understand its part of happiness emotion which seems to  be a default state when a sim does anything but be "bored" (aka neutral state) but I'd REALLLY love to see this default expression moved  to a selectable trait (ie always happy, always smiling?).

For the record I'm a pretty happy guy, but most happily people don't walk around with a smile like they just walked off the set of Batman as the Joker including myself.  Heck smiling actually requires a lot of muscles and not easy to maintain like our sims constantly do and I get it, some people might like a "happy" smiling sim but after playing..other games includng previous Sims titles (love 2 and 3) recently it really hit how awkward and unnatural it is to have sims constantly smiling often when they are just being idle too...

Hence my idea to make the idling expression related to a selectable CAS trait or perhaps a trait you unlock too for comedy, etc?

Just...something more natural to see please...