A woman lies flat out on the pavement, arms spread out in a Christ-like position, in front of a tottering white and yellow mountain of fish and chip wrappings and polystyrene fast food cartons. A shiny blue tiled shop facade glinting in electric light adds to the weird beauty of the composition. Where is this scene of nocturnal mayhem? The clue is not in the Italian baker's sign but the Welsh dragon on the bin half-hidden by overflowing waste. This photograph belongs to a portfolio by Polish photographer Maciej Dakowicz, called Cardiff After Dark.

"Captured on our streets by a foreign lens", ran the headline to a Mail Online article splashing the pictures this week, "shaming images that turned Britain into a laughing stock." Reporting that Dakowicz's pictures of weekend revellers on the streets of Cardiff have just been shown to great hilarity at the Perpignan Festival of Photojournalism, it invited readers to get dewy-eyed with revulsion at these photographs of the dreadful moral sickness of modern Britain.

Well, it's obviously true, isn't it? We are a nation of pathetic boozers, and many of the drinkers – horrors! – are women. You just have to look at the photograph that the Mail made its star exhibit, to see the most damning illumination of boozed-up Britain. It appeared thunderstruck by this picture of a woman it saw as lying unconscious after guzzling vast quantities of, it supposed, tequila. "Left out with the trash", said the caption: "A woman apparently incapable of standing lies defenceless on the streets of Cardiff."

According to the photographer, however, that word "apparently" deserves a bit more weight. He has stated to the Guardian that it is misdescribed in the apocalyptic report on the black comedy that is urban Britain:

"I explained it to the Daily Mail, but still they put a wrong and misleading caption. She was with a group of friends, they were just a bunch of people on a night out, they laughed about the pile of rubbish and she laid down on the pavement and her friends photographed her. She was not drunk, it was a joke she made with friends. It happened right in front of me, so I shot it as well."

In fact, if you look at the way Dakowicz presents the pictures on his own website, and the full range of images he has shot on the late night streets of Cardiff, where he first spent time as a student, it is clear he is judging no one. Humour is the most obvious thing about his pictures, and their attraction lies in the way they balance grotesque abandon with poised, coolly beautiful lighting. Shots that might just have been coarse snaps have a grace that makes them all the more comic, including a bloke in woman's clothes and pink hat who leans a stockinged leg on railings outside a pub which, when you look at it twice, surely seems collaborative between photographer and subject, with the man achieving an almost classical pose.

The miscaptioning of the most supposedly horrific of these photographs of wild Cardiff – turning a picture of a young woman who, according to the photographer, playfully adopted her pose into a sad shot of human dereliction – is a lesson not just in the way photographs are defined by the words that describe them, but in the universal, largely unquestioned, yet fragile cultural fantasy that is Boozing Britain.

The news story of Britain's massive alcohol problem took off just over a decade ago. Since then it has become an integral part of the culture of national self-loathing that feasts on tales of a broken society and has now reached an apotheosis in the moral backlash after this summer's riots. The Mail has found powerful visual evidence of the binge-drinking vodka-sodden state of Britain in these pictures that Dakowicz took over a four-year period in Cardiff – such good evidence that it bears repeating. This week's splash was actually their second appearance on Mail Online, which first showed them in May 2009 with the headline "Welcome to Binge Britain."

Drinking has always been a difficult subject to discuss continently. Alcohol is associated with loss of self-control, with the irrational, with acts of abandon. Public debates over excessive drinking therefore become debates about civilisation and savagery, reason and unreason in collective life – which means the imagery of alcohol rapidly escalates from sensible concern to apocalyptic fantasy. William Hogarth played on this mythic quality of drink in a clever way in his 18th century prints Gin Lane and Beer Street. His depiction of Gin Lane – topographically a portrayal of a real district, St Giles, a notorious Georgian slum – deliberately conjures up images of hell and damnation in its depiction of an urban underclass of gin addicts. Meanwhile his Beer Street is a patriotic, hearty image of the ideal British pub.

Hogarth made these prints to campaign for a reform in drinking at a time when the "gin craze" was gripping boozy Brits, but he self-consciously exaggerates the visual extremes, and thus humorously controls the irrational feelings we bring to alcohol as a social problem.

In 21st-century Britain we could do with some self-control not just about drinking, but the way we talk about drinking. You can certainly find alarming figures such a report this April that says British girls are the "biggest binge drinkers" in the western world – although even this study takes on perspective when you note that to achieve such a disturbing record, half of British 15-year-old girls interviewed admitted they had been drunk at least twice. Was it at Christmas? How much more than twice? How do they define drunk?

It may seem outrageous to casually dismiss what has become one our deepest darkest convictions about our national "shame", but the fact is that overall figures issued by the Office for National Statistics earlier this year show that drinking in Britain, by most measures, is on the decline. There is a trend for Britons to booze less, not more, and to regulate their alcohol consumption more carefully. Some evidence even suggests the recession has played its part in moderating drinking. Of course there are plenty of horror stories to set against these cool figures. So let's say the evidence is complex and contradictory, and hard to shape into a single narrative. But if the evidence for terror lies in photographs like this one, it is painfully clear that fears are outstripping facts.

Nations imagine themselves in fantastical colours. In the 1990s a feel-good Britain pictured itself as a youthful and gifted Cool Britannia with great pop music and marvellous conceptual art. Nowadays a feel-bad nation pictures itself as broken, boozing, rioting, morally sick. But these boldly coloured national stories are just fables, that have nothing to do with the contours of real life.