Racism, quite clearly, has not been "shown the red card". Racism, quite clearly, has not been "kicked out of football". David Cameron this week praised previous initiatives that had set out to rid Britain's dominant sport of this specific kind of prejudice. But that hasn't stopped him from announcing a "summit" on racism in football some time in the next month. This was in direct response to Liverpool striker Luis Suarez's refusal to shake the hand of Patrice Evra, after Suarez had undergone an eight-week ban for racially abusing the Manchester United player. The summit's announcement was also, of course, in indirect response to ongoing and high-profile tumult over what looks very much like continuing and endemic racism in the sport.

John Terry has been stood down as captain of England's football team, because he is to stand trial, charged with having delivered a racist insult. England manager Fabio Capello then resigned in protest at Terry's innocent-until-proven-guilty punishment. Meanwhile, caretaker manager Stuart Pearce has his own race-related controversy lurking in the past, as well as an embarrassing brother who once stood for the British National Party. Who needs the BNP to be associated in any way with the BNT … or British National Team?

None of this stopped the Football Association from gently breaking to fans the awful possibility that the next manager of England might be no more English than the last. And that, really, is the oddest thing of all. Prejudice about nationality is a much less big deal than prejudice about race. Why is this? Maybe it's because nationality actually exists, while race, let's face it, doesn't.

I've had a hideous realisation about racism, as I watch this nasty footballing farce unfold, which is this: as an "ism", as an ideology, racism is incredibly successful, despite having no basis at all in fact. There is only one race, the human race, Homo sapiens sapiens. Yet because racism exists, everyone bangs on endlessly about "race".

The former England player John Barnes put it very well in the Times this week: "Race is not a scientific reality. You could find a tribe in Africa who are genetically closer to Europeans than to an African tribe a hundred miles away. Some Saudis have whiter skin than Italians."

Yet, in the cause of discussing racism, or measuring its influence, "race" is accepted as some sort of meaningful system of categorising humans. Routinely, mere skin colour is referred to as something immutable – "race". One is often compelled to state one's "race" in forms, for example. One is sometimes invited to consider ticking "mixed race". Mixed race? What a ridiculous, fantastical concept. Mixed ethnicity would be more accurate, if not any more useful. Different ethnic backgrounds exist, of course. But different ethnicities are not different "races". There are broad genetic communalities among people whose ancestry traces back to the same region – that's ethnicity. It is nothing more. Anyway, trace back far enough, and it's likely that all of us came from the same place: Africa.

All this monitoring of "race" is predicated not on some essential and basic genetic division between humans, but on the existence of racism, which tries to promulgate the idea that essential and basic genetic differences between humans exist, when they don't. And racists succeed very well in promoting this empty agenda. Data on "race" is collected in order to try to understand the effects of racism. The myth of "race" has been invented by racism, and racism keeps the myth growing.

Perhaps the most rotten, abject thing is that the prioritisation of the monitoring of "race" actually distorts, squeezes out and disguises the monitoring of the true causes behind differences that are presented by racists as "racial". Economic and educational background – class background – is usually the real driver of division. Middle-class Asians expelled from Uganda have "done better" in Britain, if I can generalise, than dirt-poor, uneducated Asians brought over to work in mills that offered wages and conditions that were unacceptable to the locals. Yet one hears far more about "racial tensions in Bradford" than one does about "economic tensions in Bradford".

Likewise, racists will cite the disproportionate number of "black men" in prison as connected to "race", when it is really about economic and social opportunity. Conversely, anti-racists sometimes err in the other direction, blaming lack of opportunity almost wholly on racism, when simple lack of opportunity is reason enough for failure. Sadly, so-called anti-racists often also have a perverse investment in promoting ethnic difference as if it is racial difference. Anti-racists can end up as passionately attached to the idea of race as the people they stand against.

The most insidious thing about racism is that it is creepily self-sustaining. The more that race rather than cultural background is monitored, the more opportunity there is to pass off cultural disadvantages as racial disadvantages. In the US, for example, prison culture has been incorporated into street culture. Consequently, a background in violent criminality is viewed in some quarters as conferring a perversely glamorous sense of identity, and thanks to the racist prism it has been viewed through, consequently celebrated as an integral part of the "black" experience, rather than simply of the economically and educationally deprived experience. This sort of counter-productive and baleful confusion has been exported to Britain so unquestioningly that the historian David Starkey, in the wake of the summer riots, felt he was being bold by going on Newsnight and declaring the riots happened because "the whites are becoming black". Dear heavens.

Prejudice against others because they look "different" to you was no doubt essential in tribal societies. But from the moment tribes decided that they were going to travel in search of territory (or, in the hideous apotheosis of such acquisitive attitudes, in search of slaves), then tribalism became less … manageable. Barnes rightly describes race as having been "introduced by governments, backed by the Church, to validate slavery and colonialism, to justify treating some people as less equal than others".

Tribalism is often still expressed through nationalism. It's also expressed through sport, particularly football. This deep-rooted association of football with "racism" is probably exacerbated because football support is so often a metaphorical indication of an atavistic desire for tribal identity. Barnes, once again, puts it well: "The Football Association ticks all the right boxes with its policies and campaigns, the government passes legislation, the prime minister gets involved because someone didn't shake someone's hand, people queue up to say ignorance is no excuse. But they are wrong. Ignorance is the excuse. To stop it, we have to start talking seriously about race."

Our "race" is human. We are all just people, in a big, wide, multi-ethnic world. That's what we have to talk seriously about, instead of pandering to the ignorant eugenic fantasy that racists promote. Maybe we should just stamp out racism by desisting from talking as if we accept the racist's idiotic premise, that there's a single soul on the planet of a different "race" to ourselves.