In school, I have never heard a teacher, administrator, or the principal use vulgar language. None of our neighbors swear when talking to me or dad, and the kids I hang around with don't swear either. My dad doesn't use vulgar language, although I have heard him say some of the very mild ones when he breaks something.
I don't swear and never have. I use "dang" as the word for everything that I think needs emphasis. I don't hang around with people that swear either, only because it makes me feel uncomforable, and the person firing swear words at me surely doesn't respect me or other people. I have heard kids swearing in an ice cream parlor when families are in the next booth. That is low.
So, (IMO) I find that people who swear in mixed company or within earshot of people they don't know, show a lower intellegence than those mentioned in the beginning of my reply. Again, this is just my opinion.
Bettina