I find that the more tired I am or the more stressed I feel the more I swear. During these periods I seem so preoccupied with my emotional state my thinking becomes muddled and lazy. On these occasions I sense a destructive affect on my ability to communicate accurately - and I know this is so. I know someone who uses the F word in normal conversation with such alarming regularity I often lose the thread of what it is he is trying to say. I find myself wanting to cut him off mid way through and say to him I've had enough, I'm bored, you're never, ever going to get to the point of what you're saying with these endless, pointless gap filling repetitions.
Everything he says just becomes one big F word in the memory with a few desultory facts that I may or may not have taken in.
But for those who might think swearing always an indefensible indulgence for those too idle to control their speech, this from firstname.lastname@example.org. is as near a justification for its use, (sometimes), as I've seen: "Swearing achieves the same catharsis one gets from a hearty belch, an evening constitutional, or a good, long cry -- it's a psychic purgative when one is suffering from emotional constipation. Because men are congenitally incapable of indulging in good, long cries, swearing provides them with a handy compromise when presented with the impractical alternatives of running away, crying, or fighting. Men can be hostile creatures, and swearing often allows them to exchange oaths instead of blows. As Mark Twain put it in _Pudd'nhead Wilson_, 'When angry, count four; when very angry, swear'."
--Richard Dooling, American writer and lawyer, "Blue Streak", 1996.
I wonder if swearing in another language would work if you needed a psychic purgative - handy perhaps when in the company of sensitive souls.