intellectually lazy? It probably has nothing to do with raw IQ score, but I do think it says something about character, eloquence, self discipline (and upbringing).

It also depends very much on where you were raised. I served my mission in coastal Colombia and parents regularly used the Spanish equivalent of the F-word at their children all the time. Missionaries that came from other countries or even other part of Colombia were shocked by how much it was used in casual conversation (even among Church members).