I’ve read that too. That cussing can be a sign of higher intelligence. They also say staying up late is another sign. I do neither of those things yet I am told I am above average. So I guess it depends.
Haha, I bought my first kinky magazine in middle school and learned a bunch of sexual words from it. When my parents found out that I’d been talking dirty to my only female friend, they went into a frenzy and scolded me real good.