How long can the 'Keep Calm' trend carry on?

At first it seemed clever and cute. Then the 'Keep Calm' motif went mad, spawning endless offshoots

People of a certain age might remember a piece of graffiti that used to get scrawled here, there and everywhere. I first encountered it at school, but it had been amateurishly drawn by kids and adults for a good 30 years before I had my first stab at it. It consisted of a bald-headed man, with a big nose, peeping over a wall; in Britain he was known as Chad, but if you're Australian you might have known him as Foo. If you're Polish you'd have called him Józef Tkaczuk. Or Sapo if you're from Chile.

While various theories exist as to what that figure might represent or where it might have originated, barely anyone knew or cared about its history as they scribbled it on a desk or a wall. It was just a thing.

A thing they'd seen other people draw, and now they were going to draw it, too. It was a cultural oddity that lasted decades, but eventually, slowly, it died out – in the same way we stopped hosting Tupperware parties or dressing our children up as sailors. You rarely see Chad these days.

Many now wish for the slow death of a similarly puzzling cultural phenomenon known as Keep Calm And Carry On, which I'll keep abbreviated to KCACO in order to avoid provoking unnecessary distress.

You don't need me to tell you that KCACO and its many variants are everywhere; it's like a painful rash breaking out across villages, towns and cities, from posters in launderettes to election leaflets, from the backs of white vans to stacks of mugs in gift shops. KCACO is so easily subverted that it's become the perfect meme, endlessly imitated and copied, taking on a life of its own and using humans as an unwitting propagation mechanism. A Facebook group entitled 'Plague' collects some of the worst, including such horrific and meaningless examples as 'Keep Calm And Gangnam Style'.

If you were asked to define the characteristics of a KCACO-style design, you'd probably say that it should have a red background with a symbol at the top, and contain the phrase 'Keep Calm' followed by 'And' on the next line and then another series of words below that – all in upper case. But there are no hard-and-fast rules. You could omit any, one or more of these characteristics and still produce a KCACO; I've seen green ones, blue ones, ones with 'Keep Calm' replaced with 'Keep Warm', or 'Save Water', or 'Deny Self' – or, on one extraordinary poster in Peckham police station, 'Anything You Say' (May Be Taken Down And Given In Evidence). You could say that KCACO is out of control.

The story of KCACO is often told, but now that examples of it are on sale in gift shops in American seaside towns, it's conceivable that some owners of KCACO objets d'art aren't aware of its history. So here's a quick précis: Stuart Manley, proprietor of Barter Books in Alnwick, Northumberland, discovered a folded poster at the bottom of a box of secondhand books back in 2001. Research established that it was one of a series of three posters produced by the Ministry of Information during thef Second World War, and was intended as a reassuring propaganda tool to lift spirits during a time of austerity and fear.

Despite 2.5m KCACO posters being printed, it was never displayed publicly and nearly all of them were pulped. Pulled out of a box decades later, however, KCACO seemed like a glorious memento of British pluck, of stiff upper lip, of a phlegmatic attitude towards wartime hardship. I read about KCACO not long after Barter Books started selling copies; I bought one and stuck it up in my hallway.

The sentiment was sound. I liked it.

But a few years later I found myself defacing it one evening with a marker pen. It no longer had any positive associations. Endless, relentless repetition had evaporated any charm it had once possessed.

I left it on the wall for a few months, covered in scrawled expletives, but eventually threw it in the bin, banishing it from my home. On my local high street and in my letterbox, however, KCACO was still very much alive. I was instructed to Keep Calm And Eat Pizza (as if I was ever likely to be in a state of agitation before eating pizza) and to Not Keep Calm And Save Lewisham A&E, among hundreds of other things. It's possible that I was oversensitive to KCACO, but the plague appeared to be unstoppable. And becoming less amusing by the hour.

"It's like picking up on a gag in a conversation and doing a really bad, unfunny version," says Mark Earls, consultant and author of the books HERD and I'll Have What She's Having. "We do this all the time, because we're social creatures. We mostly do what other people do." Earls puts the success of KCACO almost entirely down to spontaneous and unquestioning imitation. "You might imagine that there's something about the poster which made it popular – and perhaps there was, initially. But this is about people. It has very little to do with the quality of the thing itself. Many things become successful not because they're great; we attribute qualities to their success that simply aren't relevant."

In 2007, an ex-TV producer named Mark Coop managed to obtain an EU trademark for KCACO, and he still owns and runs a website at keepcalmandcarryon.com. When he tried to protect his newly-acquired rights by complaining to eBay about vendors using the slogan, he came up against fierce criticism for daring to flex legal muscle over a bandwagon that he was also accused of jumping on.

In a statement, he criticised copycats for "tarnishing the charm" of the poster – but Coop's entrepreneurial success was a big contributory factor towards KCACO "jumping the shark"; the mass production of mugs, tea towels and iPhone cases inevitably breached that tipping point between cute oddity and omnipresent irritant. What's strange is that we still persist in buying KCACO-branded gubbins in huge quantities; a search for the phrase 'Keep Calm' on eBay turns up nearly three quarters of a million items.

"It's the same as when we go to the supermarket and drift towards the most popular brands," says Earls. "Economists say that humans are genuinely looking to maximise utility, but we live in a world where there are so many choices that often we just settle for 'the OK thing'. We think to ourselves, 'Well, what's popular?'." So if we don't know what to buy a nephew for his birthday, we'll just walk into a shop, recognise something and buy it? "Exactly. Job done."

This lack of ingenuity extends into the field of marketing, which is equally happy to use KCACO to flog us goods and services. "It's all about instant recognition," says marketing strategy consultant Sam Bridger. "The holy grail is high brand awareness; it acts as an instant shorthand. So anything like this that passes into common parlance has immediate 'acceptance'. People instantly get it. KCACO seems to have more staying power because it can be flexed to suit any situation."

Easily adapted, instantly recognised – no wonder that if your local corner store, builder's merchant or Ukip candidate is stuck for a marketing idea, KCACO is the one they'll plump for. As a design choice for a poster, it's become as unremarkable as deciding to use a piece of A3 paper. Why waste time coming up with something better? "One of the things that makes our species so successful," says Earls, "is our ability to outsource the cognitive load. We copy the work of other people to make our lives easier, so we can spend our time worrying about things we deem to be more important."

Just like Chad graffiti in 1954, or even 'Frankie Says…' in 1984, KCACO will, in years to come, be seen as a cultural characteristic of this era. You may find this profoundly depressing. But don't get too upset about the supposed violation of the original spirit of KCACO. The truth is that the stoic commands of wartime propaganda never resonated well with the British.

The first two posters produced by a green and inexperienced Ministry of Information were, in fact, greeted with indifference and disdain. The Times referred to them as "insipid and patronising". And faced with the task of distributing 2.5m copies of the third poster, 'Keep Calm And Carry On', to a public almost guaranteed to hate it, perhaps it's not surprising that the government had them all destroyed. But the one that survived, and was rescued from a box in Northumberland, ended up inspiring indifference and disdain of a rather different kind some 70 years later.

Maybe we were never meant to like it. Maybe if we ignore it, it'll go away.