I don’t think swearing and writing go together but neither do I think it reflects a lack of intelligence. It has its place, especially with British stand up comics. Pretty much all the comedians I watch swear, but they use it well and it works. I think Jimmy Carr’s hilarious, by the way, and very intelligent. I heard him being interviewed on Rob Becket and Josh Widdicombe’s podcast recently, and he was genius! And he’s very good at laughing at himself, which is a sure sign of emotional intelligence.