Bad language could be good for you, a new study shows. For the first time, psychologists have found that swearing may serve an important function in relieving pain.



The study, published today in the journal NeuroReport, measured how long college students could keep their hands immersed in cold water. During the chilly exercise, they could repeat an expletive of their choice or chant a neutral word. When swearing, the 67 student volunteers reported less pain and on average endured about 40 seconds longer.



Although cursing is notoriously decried in the public debate, researchers are now beginning to question the idea that the phenomenon is all bad. "Swearing is such a common response to pain that there has to be an underlying reason why we do it," says psychologist Richard Stephens of Keele University in England, who led the study. And indeed, the findings point to one possible benefit: "I would advise people, if they hurt themselves, to swear," he adds.



How swearing achieves its physical effects is unclear, but the researchers speculate that brain circuitry linked to emotion is involved. Earlier studies have shown that unlike normal language, which relies on the outer few millimeters in the left hemisphere of the brain, expletives hinge on evolutionarily ancient structures buried deep inside the right half.



One such structure is the amygdala, an almond-shaped group of neurons that can trigger a fight-or-flight response in which our heart rate climbs and we become less sensitive to pain. Indeed, the students' heart rates rose when they swore, a fact the researchers say suggests that the amygdala was activated.



That explanation is backed by other experts in the field. Psychologist Steven Pinker of Harvard University, whose book The Stuff of Thought (Viking Adult, 2007) includes a detailed analysis of swearing, compared the situation with what happens in the brain of a cat that somebody accidentally sits on. "I suspect that swearing taps into a defensive reflex in which an animal that is suddenly injured or confined erupts in a furious struggle, accompanied by an angry vocalization, to startle and intimidate an attacker," he says.



But cursing is more than just aggression, explains Timothy Jay, a psychologist at the Massachusetts College of Liberal Arts who has studied our use of profanities for the past 35 years. "It allows us to vent or express anger, joy, surprise, happiness," he remarks. "It's like the horn on your car, you can do a lot of things with that, it's built into you."



In extreme cases, the hotline to the brain's emotional system can make swearing harmful, as when road rage escalates into physical violence. But when the hammer slips, some well-chosen swearwords might help dull the pain.



There is a catch, though: The more we swear, the less emotionally potent the words become, Stephens cautions. And without emotion, all that is left of a swearword is the word itself, unlikely to soothe anyone's pain.