Felipe Fernández-Armesto: We are all good at something. But the vain believe they've got the lot

Self-love is an evolutionary trick for over-riding our deficiencies

Cristiano Ronaldo has something to be vain about. Therefore, despite his ex-girlfriend's accusation and his own touching admission, he is not really vain at all: just justifiably proud – albeit sadly so, in the fleeting excellence of boyish good looks and footballing brilliance. Real vanity is contemptible because it is vacuous and out of proportion to any genuine merit that may underpin it. The self-admiration of Cinderella's ugly sisters is classic vanity. One of its modern manifestations is the crazy self-evaluation of bankers and brokers who award themselves fat bonuses for failure.

There is a lot of real vanity around in Britain today. This country, once admired for modesty, reticence and people's ability to understate their own virtues, is now Europe's Vanity Fair: the land of idle boasting, over-valued incompetence and overpriced worthlessness.

Some British vanity is innocent – reflected in the market for fake tans, hair colour, flashy clothes and gyms as empty as their patrons' pretensions to fitness. Much vanity is simply silly. You see it every summer when slobs expose their revolting bodies. In former times, their parents taught them to be ashamed even of beautiful bodies. Now they are defiantly proud of their own indecency.

Television talent shows are full of people who make laughing stocks of themselves by egregious over-confidence in their flat feet and flat voices. Thousands of idiots have the temerity to present themselves for quiz shows, only to end up deservedly in the Dumb Britain column of Private Eye. Anyone who has to read job applications or Ucas forms has a desk piled with candidates' overoptimistic ambitions, belied by their indifferent exam results and their inability to spell or punctuate. Recruiters with jobs at their disposal encourage applicants in vanity by asking them to name their strengths, and rewarding the immodest.

Cosmetic surgery is a sure index of British vanity, because people have it when they over value their looks or think a quick fix is all they need to be beautiful. This is a country where a novelist spends £6,000 having his teeth fixed in a hopeless attempt to mask his ugliness. According to the latest statistics, operations to inflate women's breasts and slice off their body fat increase by 50 per cent year on year. When I went to a snooty art exhibition the other day, I could barely look at the pictures because of my horrified fascination with the expensively re-modelled faces of the rich old harridans around me – permanently distorted into rictus by the surgeon's knife, to serve the vanity of women who thought they could easily make themselves look young or lovely.

Vanity is laughable when it is self-harming, but becomes a serious vice when it harms others. MPs of feeble abilities, who think they are worth so much more than their salaries that they feel justified in fiddling their expenses, are guilty of a particularly deplorable form of vanity. So are Government ministers so convinced of their own indispensability that they use resignation as blackmail. So are company directors who set their own salaries at levels that amount to cheating their shareholders and employees. So are the cocksure professional snoot-cockers such as Jonathan Ross or Gordon Ramsay, who are so pleased with themselves that they think they are exempt from normal good manners. So are workers who strike for more pay or privileges than they honestly earn, or people who idle because they think they "deserve a break", or fools or charlatans who demand "respect" for daft opinions, false dogmas and fantastic or mythical versions of the past.

Even more pernicious is the vanity you find among maddeningly self-obsessed gurus, mullahs, prophets and self-ordained pastors, who are convinced that their ravings are inspired by God. More alarming still is the vanity of Britons who have so little to commend them that they take pride in the worthlessness of being merely British or merely white. Vanity gets really vicious when it takes to the streets with a knife and gives morally worthless gangs the confidence to demand "respect" with menaces. People with properly humble self-evaluations threaten no one and are well equipped to get along.

How did Britain succumb to the vanity virus? The germ, at least, was always there. Vanity underpinned traditional snobbery, which is a misplaced sense of superiority in belonging to a particular school or set. Being top nation for so long in the 19th century tempted Britons into assuming effortless advantages. "How shall we extol thee," ask the lyrics of Land of Hope and Glory, "who are born of thee?" The answer, of course, ought to be, "Not at all, unless the British-born have some other merit." Still, satire lampooned these follies. No one in the audience of HMS Pinafore really believed of the mock hero that "It is greatly to his credit that he is an Englishman."

Vanity made ground in the 20th century. In the Second World War, government propaganda overdid the morale boosting: on VE Day, my father's landlady in London told him that the British were "the greatest race in the world". A series of comic guardian angels, from ITMA to Beyond the Fringe to Bremner, Bird and Fortune have striven to preserve British modesty by pricking British pomposity. In the long run, bad education and cod psychology have beaten them. Britons are now taught "self-esteem". For those with few qualities and low attainments, this is a fatal urge. In the feel-good society, no form of vanity is more corrosive of morality. If you feel good about yourself all the time, you have no incentive to improve.

The British case is sad, because it involves the loss of a once characteristically British virtue. But the triumph of vanity is not, of course, confined to Britain. In the search for a proper level of pride, humans tend to overshoot the mark. Everyone is good at something or for something: the difficulty lies in identifying what that something is, and staying humble about everything else. At a deep level, vanity is an evolutionary mechanism for overriding our deficiencies.

But if vanity is general in Britain and widespread in the world, why is Ronaldo getting so much stick for it? Justifiable pride edges into arrogance, which is, perhaps, Ronaldo's real vice. Fans dislike him, even when they admire his skill, and grudgingly concede his superiority, because he evinces an attitude of contempt for inferior opponents, critical supporters and myopic referees. He crows in victory and sulks in defeat. He blames everyone but himself when he plays poorly or submits to tactical substitution.

Though the British are now at least as vain as everybody else, they still regard arrogance as a foreign sin – which indeed, in some sense, it is. In Spanish and Portuguese, the words for arrogance can confer admiration, a sense of superb privilege, inherited from the deeply embedded historical traditions inherited from warrior aristocracies. Ronaldo's football – its poise, its balletic razzle-dazzle, its ruthlessness – recalls the acclaimed arrogancia of a matador.

So Ronaldo will be better off in Spain. In choosing Real Madrid he has added cleverness to his checklist of qualities to be proud of. He demonstrated cunning in masking his intentions with the rhetoric of loyalty to Manchester United. He has shown common sense in accepting a flatteringly high salary. He has displayed wisdom in going to a better club. For Real Madrid has much more glory in its trophy cabinet than Manchester United, and far more honour as a club. It is a real club, not run for the profit of millionaire owners, but focused solely on playing great football. It is not a faceless mega-business that exploits its fans, but a joint enterprise of all the club members, who elect and remove chairmen democratically. Like Ronaldo, it is guilty of arrogance, and it is hard to resist feelings of pleasure when Barcelona – a similarly noble footballing institution – wins at Real's expense.

But Ronaldo is about to make a move every footballer might envy. Perhaps enviability is the key to his unpopularity in Britain. For envy – of talent, of wealth, of success – is another British vice, with a much longer pedigree than vanity.