To swear, except when necessary, is becoming to an honorable man. —Quintilian
1. Pain relief. Swearing activates the so-called 'fight or flight' response, leading to a surge of adrenaline and a corresponding analgesic effect. Richard Stephens of Keele University in England found that people who swear are able to hold their hands in ice-water for twice as long. However, this only holds for people who swear a few times a day, not for so-called 'chain-swearers'. Presumably chain-swearers are densensitized to their swearing, and so not particularly aroused by it. It remains unclear whether some swear words are more effective than others. But it seems very likely.
2. Power and control. Swearing can give us a greater sense of power and control over a bad situation. By swearing we show, if only to ourselves, that we are not passive victims but empowered to react and fight back. This can boost our confidence and self-esteem, and also provide the impetus for further corrective action to be taken. As Mark Twain put it, 'When angry, count to four; when very angry, swear.'
3. Non-violent retribution. Swearing enables us to get back at bad people or situations without having to resort to violence. Instead of punching someone in the face or worse, we channel and disarm our anger by swearing instead. True, swearing can also have hurtful consequences, but better a few sharp words than a sharp dagger. Swearing can also serve as a warning signal or as a marker of rank and authority, a bit like an animal's growl: "Watch out. Stop it. Or you're damn well going to pay the price."
4. Humour. Swearing among friends can be quite hilarious. In such circumstances, it represents a release from normal social constraints or, like play-fighting, makes light of a potentially threatening person or situation.
5. Peer and social bonding. Swearing can serve to show that we belong in a certain group, or that we are able to be ourselves and so wholly comfortable with the members of that group. If done correctly, it can also signal that we are open, honest, self-deprecating, easygoing, and barrel loads of fun.
6. Self-expression. Swearing can be a way of showing that we really mean something or that it is really important to us. That's why swearing is so much a part of any sport. It also broadens our register and makes us more lively and interesting, being used, for example, to add emphasis or 'punch' to our speech.
7. Psychological and physical health. The health benefits of swearing include increased circulation, elevated endorphins, and an overall sense of calm, control, and well-being. The key is to do it sparingly and not to get angry at the same time, which would be very bad for you—as well as terribly vulgar.
If you can think of any other good reasons for swearing, please be sure to add them in the comments section.
Neel Burton is author of The Meaning of Madness, The Art of Failure: The Anti Self-Help Guide, Hide and Seek: The Psychology of Self-Deception, Heaven and Hell: The Psychology of the Emotions, and other books.