So, I've been wondering this for a long time. Every website I go to says that normal Friendly interactions will raise your Sim's Charisma skill, but I don't see the bar filling up with green when they...
I don't think all the friendly interactions do. My sims that don't focus on it only get about 3 or 4 levels in it. I think interactions like deep convo, discuss interests, & tell story are what really raises it casually.