SO YOU meet somebody twice a year, and every time, you say: “Your wife was killed in a car crash, and I’m really glad.” And you have been doing this for half a century, and the pleasure of saying it has only increased over the years. Every time you see this person, you make driving and throat-slitting gestures. How amusing it all is!

We read in The Times this week that a small group of Manchester City supporters have written an open letter to others of their kind. They are making the suggestion that they all stop taunting Manchester United supporters about the Munich air crash of 1958, in which 23 people, including eight United players, were killed. But it’s not the stopping that is intriguing, it is that they started in the first place.

It is a fact that many sports, especially football, are not complete without this quantum of vileness. Vileness seems to be an inextricable part of sport, and as all of us reading these pages are presumably followers of sport, it is worth looking at the phenomenon and at ourselves.

Football has a routine of vileness. Some teams are traditionally hated. When a player from such a team takes a corner, those seated near by shower him with taunts and obscene gestures. For some, football is a festival of hate. I will always remember the man I saw carried horizontally from a match, struggling furiously with every pinioned limb, so consumed with hatred that he had lost all control. The match was Luton Town against Watford: a cause for which, at that moment, he would willingly have died.

But let us not be snobbish. Go to Twickenham and you will hear plenty of abuse. It is not chanted and orchestrated, but no match is complete without a whiskified voice — always thoughtfully placed precisely behind the press box — yelling abuse at the referee. This is presumably a sensible grown-up, reasonably successful in his professional life, a comparatively intelligent person who nevertheless finds pleasure in attending an international rugby union match and shouting “You bloody disgrace” for 80 minutes.

Cricket has always been full of crowd banter, some of it nasty, some of it witty and appropriate — “leave our bloody flies alone, Jardine,” as Yabba so trenchantly remarked from the Sydney Hill. But these days, cricket’s abuse is structured and choral. This summer, throughout the Ashes series, the crowd chanted “Where’s your missus gone?” at Shane Warne, a great cricketer enduring personal trauma.

The Barmy Army claims to be a benign presence, but goading Jason Gillespie with “Where’s your caravan” as a tribute to his supposed Gypsy origins is unambiguously racist. Hitler thought so, anyway, when he consigned Gypsies to the death camps.

No sport is entirely immune from vileness. Racing crowds are generally cheerful and united against the common enemy, but any jockey who has lost on a favourite — ie, all of them — will tell you that racegoers are charming within strict limits. I have, for that matter, been threatened with violence at the Wimbledon tennis.

I covered speedway when I worked on local papers, and I used to meet a colleague from a rival newspaper at the track. He loved the sport, was generous with his knowledge and was great company. A nice man, in short. And every time Ivan Mauger, the great New Zealand rider, used to compete against the Dons, he would shout: “I hope you break your f***ing leg!”

The phenomenon baffles me. I have never been tempted to shout abuse on any sporting occasion. This is not to claim the moral high ground: my vileness is simply expressed in other ways. But the fact is that sport brings out the quantum of violence in many of its followers, and it is an inextricable part of the sporting life.

As some occasions require you to come along with a top hat, so others require you to bring bad vibes.

The key to at least part of this lies in Graham Greene’s Travels With My Aunt. Wordsworth, Aunt Augusta’s Sierra Leonean manservant-lover (“He had superb knackers”), is vilely rude to the nephew through the entryphone of her flat, but is all smiles when they meet in person. “Don’t you be vexed with old Wordsworth. Ah just like to make dat machine say bad things.”

The sporting crowd is not an individual, but an individual can speak through the machinery of the crowd, so it doesn’t really count. Sociologists talk about “deindividuation”, the loss of self-awareness and personal identity that happens to someone subsumed in a crowd.

Gustave Le Bon, a pioneering French sociologist, talked about “the law of the mental unity of crowds”. He made the essential point that a crowd is quite different from a lot of people all coming together by chance and for different reasons. A sporting crowd is united by definition, and therefore operates by different laws than those that govern the behaviour of individuals. A vileness an individual would never dream of uttering to another individual is perfectly acceptable when you are in a crowd.

In a crowd you are not only safe, you are a different person.

Exalted by fervour, taken out of themselves, sent into an ecstatic state by the shared emotions of sport, members of a crowd are freed from the normal restraints. And in sport, very often, people use that freedom in order to be vile. Sport is oppositional: perhaps vileness is as inevitable in sport as spiritual exaltation is at a revivalist meeting.

For crowds are not by definition vile. Half a million people spent three days in unspeakable conditions at Woodstock and the overwhelming emotion was a vast self-congratulatory love. Had the Jimi Hendrix Experience played Crosby, Stills and Nash at football or tiddlywinks, things might have been different. Music is not oppositional, sport is. Music unites, sport both divides and unites.

There is a culture of vileness in sport: that is something that must be faced by all sports enthusiasts. All of us who love winning must accept that we share something of the oppositional nature from which vileness springs.

All the same, it is worth reflecting that a culture of vileness can change. Racist chanting was part of sport for 30 years and more: now it has been demonised almost out of existence in this country. Partly, this is because stewards are hot on it, ignoring other routine vilenesses. But the lack of racist chanting is now a matter of self-regulation.

However, the tradition of routine vileness is as much a part of sport as, well, alcohol. Some see this as a “safety valve”, as if the vileness would be expressed in other, perhaps more dangerous, ways without sport.

But I think sport provides an opportunity for vileness, one that would otherwise be missed. Vileness is one of the reasons that sport is attractive. It’s great when my lot wins, but it’s also pretty good when your lot loses.

All who follow sport understand that. Perhaps sport is impossible for us all without that quantum of vileness.