What is the secret behind Manchester United’s unique appeal?

The thing about Manchester United is, I’ve never heard any football fan — at least not in the English-speaking world — say that he or she did not care one way or the other about what the team does, or does not do. The very mention of the club evokes either unconditional love or irrational hatred.

Perhaps no other club side in any sport within a few million light years of the Pale Blue Dot (Earth, as described by the inimitable Carl Sagan) that we inhabit can make for such sharp polarisation.

If 1000reasonstohatemanunited.tumblr.com does not quite make the point, then how about this: a devastated 18-year-old from Bingham in Nottinghamshire desperately called Britain’s emergency services line — 999 — not long after Manchester United’s Nani was booked out of the Champions League game against Real Madrid by a Turkish referee.

Surely, Turkish kebabs won’t be among the season’s culinary delights in Manchester, and in many other parts of the world — in places where Sir Alex Ferguson’s side provides the very reason for existence, adorning it with the kind of meaning that many a great philosopher might have found missing from it!

If the world of football will always be divided about United, then there can be no arguments over a few facts. A survey commissioned by the Club last year — and conducted by Kantar, a market researcher — revealed that Manchester United had not only doubled its global fan base in five years, but more importantly, half its supporters lived in the Asia-Pacific region.

The survey team sought responses from 54,000 people in 39 countries and came up with the astounding conclusion that Manchester United has 659 million followers worldwide. Forbes magazine, for its part, puts the Red Devils at No.1 among the top ten most valuable teams in the world of sport. Two months ago, United was valued at $3.3 billion by Forbes.

Now, before you conclude that this columnist was a Manchester United supporter himself, let me tell you this. I believe that Barcelona under Pep Guardiola (2008-2012) is the greatest Club team I have ever watched.

Not even the great Manchester United trio of the matchless 1960s — George Best, Bobby Charlton and Denis Law — could have matched Messi, Iniesta and Xavi. And Messi may be indubitably the most mind-bogglingly gifted footballer of all time. But that is really not the point of this column.

As Ferguson’s boys steadily gallop towards the team’s 20th English league title, it may not be inappropriate to try and unravel the Manchester United phenomenon; there has been nothing comparable in team sport.

Last week, a single incident — Nani being sent off by Cuneyt Cakir — kicked up such a storm that you might have come to believe that it could trigger the sporting version of World War III.

“I’ve never, ever experienced a shock like it on a football field,’’ said Ryan Giggs, after his 1000th appearance for the world’s most popular club. In towns and cities thousands of miles away from Old Trafford, tens of millions of men, women and children would have found their hearts recording something quite as seismic.

Even our distant ancestors knew that grief and glee were not distinctively human emotions, and were displayed in various forms right across the mammalian spectrum. And it is not as if Manchester United fans have tear ducts that are evolutionarily different from those the rest of us possess; or even that the I-hate-Manchester-United types are more prone to schadenfreudian displays of delight than the rest of us.

So what is it about Manchester United that sets off such extreme reactions across the globe? And, more significantly, what gives the team its special aura?

Scientific studies have revealed that teams in red outfits tend to do better than others. But it would be downright silly, if not nonsense on stilts, to put Manchester United’s success and appeal down to its colours. Mono-causal explanations are often easy to come up with, but they seldom stand up to strict scrutiny. Manchester United’s unique appeal is the result of a complex web of inter-woven factors, not the least of which is the weight of tradition. The United- United Fan connect has an emotional depth and psychological complexity that cannot be explained away easily.

If Matt Busby and Busby’s Babes — eight of whom died tragically in a plane crash in Munich in 1958 — started it all, then George Best, arguably the most gifted player to have worn the club’s colours, single-handedly turned United into the world’s most famous team. He had the Hollywood good looks, rock star lifestyle and a pair of legs that Rudolf Nureyev might not have wanted to disown.

In the event, I suspect there might be a few Manchester United fans among the !Kung tribe in the Kalahari Desert, and maybe one or two among the most recently sighted — aerially — Amazonian tribe that has never, ever been contacted by outsiders!