A study shows that those who swear often are frequently highly intelligent:
“The overall finding of this set of studies, that taboo fluency is positively correlated with other measures of verbal
fluency, undermines the [normal] view of swearing”. (http://www.dailymail.co.uk/sciencetech/article-3949986/Is-swearing-sign-intelligence-People-curse-larger-vocabulary-don-t.html).
I am no plaster saint and will use the odd expletive from time to time. It is, however almost always under my breath and not something of which I am proud. In my (admittedly unscientific experience) those who employ profanity in their everyday interactions with others do, almost invariably possess a limited vocabulary which accounts for their inability to communicate without utilising swear words. In short I am unconvinced by the findings of this research.