I read somewhere among the literature that brooding and smiling less cultivates more of an attraction.

At work I'm currently trying to manage the balance of being stoic and brooding as well as being charismatic and funny.. I don't understand if I'm being funny is it too much to smile and be normal or is it better to hold a stoic esq face when being charismatic. Naturally I'm more inclined to smile, so I was wondering if there is an excerpt or field tested advice that someone could provide in this instance?

does anyone have any good tips/stories on how they were funny and then went back to brood or being stoic or maintaining both at the same time.. also, how much attraction could you amongst a group if your face is stale and uninteresting.. I feel it would be a turn off to watch a stale face contrasted to one teeming with life??