If you look at a number of contemporary concerns, from crime to immigration to social injustice, it’s noticeable that race is a recurring theme. Yet the fact remains that for most of us, certainly of the white population, the subject is a no-go area. We leave it to ethnic community leaders, politicians and social scientists to deal with. Our sole obligation, it seems, is simply not to say or do anything that might be construed as racist. But is this enough?

One of the questions I pose in my new book, The Fallout: How a Guilty Liberal Lost His Innocence, is whether as a liberal society we have allowed race to become a self-perpetuating problem. Geneticists almost universally agree that race has extremely limited meaning in any biological sense. Yet its cultural significance is such that when we talk about someone being “black” the word tends to suggest far more than a description of skin colour.

One proof of this is the pejorative slang term “coconut”, meaning someone who is black on the outside but white on the inside — or put another way, someone who looks black but acts “white”. For in reality, almost all of us good liberal anti-racists carry around a set idea of what being “black” entails: physically strong, non-academic, in some way anti-authority and of course promiscuously heterosexual. And anyone, particularly a male, who does not adhere to these preconceived notions is by definition somehow less black.

I got thinking about this imprisoning idea of blackness when I visited a largely black school in South London and met a talented young poet. His teacher told me that the pupil was in constant risk of expulsion as he tried to conform to a group image of toughness and resistance to education.

It struck me that teachers like my friend had been trained in anti-racism and diversity awareness, that society at large had become progressively less racist in the past three or four decades, employment opportunities had considerably increased, and yet statistics showed that the academic achievement of Afro-Caribbean boys had either not improved or declined during that same period.

For the anti-racist ideologues the answer was simple: racism. It had not gone away, it had just become more subtle. And in a way they were right, I think, although not in the way they thought. First of all, a large part of the racism that I witnessed came from within black communities themselves, where low expectations and cultural stereotypes were often aggressively enforced. Then there was the kind of “well-meaning” racism, no less restricting, in which I had been complicit.

I recalled, by way of example, an interview I once did with an obscure political aspirant by the name of Derek Laud (later to achieve a greater profile as a contestant on Big Brother). When I met Laud in 1997 he was the prospective Tory candidate for Bernie Grant’s Labour stronghold of Tottenham.

Laud dressed like an Edwardian gentleman, spoke in a camply posh voice, was a member of the right-wing Monday Club, and an enthusiastic fox-hunter. In other words, he wasn’t very “black”. Naturally, as a good liberal, all I did was talk about his race.

After teasing out all the apparent contradictions of Laud’s existence as a black man, I put it to him that it must have taken a great deal of willpower to ignore his own racial identity in the homogeneous environment of the Reform Club, where we met.

“This is your problem,” replied Laud. “You clearly think of me as being black.”

At the time, I thought this was a tragicomic case of self-denial. And I quickly pointed out that he was indeed black. To which he said: “I never wake up in the morning and look at my face and think: ‘Gosh, I’m black.’ ” Of course, I never woke up and thought I was white, but that was different: I was white. I wasn’t fighting my own racial oppression. Had he never heard of black consciousness? It was agreed by every approved authority on the matter that the way to liberation from racial prejudice was to “get in touch” with your racial identity.

But what does that mean? Or rather, what has that turned out to mean?

There is little danger of urban black youths being unaware of their identity as young black men. Its ubiquitous imagery is sold back to them with all the crude repetition of a 50 Cent album. And this self-dramatising idea of blackness has helped to create a mental ghetto that is every bit as debilitating and limiting as the real ghettos taking shape in our cities.

One way of correcting this situation, which almost everyone in theory agrees upon, is to challenge racial stereotypes. In which case there can be few greater challenges to the Afro-Caribbean stereotype than Laud: gay, camp, sardonic and Tory.

I was wrong about Laud. I don’t mean to say that he should be held up as some kind of role model; only that if the black story is to evolve beyond a constraining identity of victimhood and oppression, it first needs to embrace people like Laud. And then, the real test, it needs to be big enough to let them go.

Instead, the British African pressure group Ligali dismissed the “gay pseudo intellectual”, after his Big Brother appearance, as a “prime example of cultural disinheritance”. Alas, this is an all too typical bitter reaction to anyone who doesn’t put their blackness first. The truth is, however, that until people with black skin can reject and select their own culture they will never truly be free.

The Fallout: How a Guilty Liberal Lost His Innocence is published by Jonathan Cape on September 6

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