The wheels of progress are regularly oiled by simple, often accidental, observations. Take Alexander Fleming’s untidy lab, in which a Petri dish was contaminated with mould. It was the only dish from which the staphylococci bacteria that he had been culturing had vanished. Fleming duly followed the clues and hit on one of the most important discoveries — that penicillin slays bacteria — in the history of medicine. Chemistry, in particular, benefits from serendipity: unplanned combinations of ingredients and circumstances have led to such discoveries as vulcanised rubber (for tyres), explosives and superglue.

And, last week, scientists pursued a seemingly trivial aspect of human behaviour and squeezed something unexpectedly fruity out of it. Why do we utter expletives when we hurt ourselves, wondered the psychologist Richard Stephens after he hit his thumb with a hammer while building a garden shed. From this emerged the highly entertaining finding that swearing helps us to deal with pain.

Dr Stephens, from Keele University, asked 64 students to plunge their hands into buckets of icy water while chanting their chosen curse. The experiment was then repeated without the volunteers turning the air blue. To sum up alliteratively: expletives extended endurance. On average, a person could keep his or her hand submerged for two minutes while swearing, compared with one minute 15 seconds while uttering a neutral word.

The question is, how is it that we can put off pain through profanity?

Dr Stephens suggests that swearing switches us into aggressive mode, triggering the fight-or-flight response. In this adrenalin-pumping mindset, we are better able to deal with adversity, such as a frozen hand. In effect, Dr Stephens concludes, swearing serves a physiological function; that this might explain why cursing has been around for centuries (if not longer); and why we should beware casual swearing lest its overuse diminish its painkilling powers.

By turning everyday observations into fodder for the lab, Dr Stephens is following a tradition in psychology carved out most notably by Stanley Milgram, the Yale psychologist. Some of his most famous experiments derived from things that he saw in the course of his life. His obedience experiment, which showed that an ordinary human being could be commanded to do the most appalling things (such as administer a lethal electric shock to a stranger when instructed by an authority figure), was borne of his observation that “the individual who is commanded by a legitimate authority ordinarily obeys. Obedience comes easily and often. It is a ubiquitous and indispensable feature of social life.” As it was in Nazi Germany, so Milgram found in a laboratory setting. In this scenario, people see themselves as mere agents of authority, relinquishing their moral reasoning to fulfil the white-coated whims of another.

Anyway, back to pain. Dr Stephens’s sore thumb leads me, via a random cerebral walk, to another compelling pain story that emerged this week, namely that the agony of childbirth is a good thing and that epidurals are evil. OK, I’m hyping it up a little, but a (male) professor of midwifery, Denis Walsh, insists that the pain of childbirth is a rite of passage that is being medicated out of existence by the overuse of epidurals. The torturous experience, he says, strengthens the mother-child bond and eases the path to motherhood. To which I — an evangelist for epidurals and most other medical wonders of modern life — propose the following experiment. Professor Walsh should be made to enunciate his views to a labour ward full of heaving, sobbing, sweating, screaming women as their nether regions are torn asunder. Not only would it allow Dr Stephens to refine his theory that swearing relieves pain, but we would also get a clear idea of Professor Walsh’s flight response.

Times Recommends

• Times Christmas appeal: Letter from the Editor
• Conferences — what a waste of money
• Schools supremo learns a painful lesson