Some years ago, one of my daughters, having shown academic brilliance at school, as well as fleet-footedness at athletics, appeared to throw it all overboard in the spirit of rebellion. Teachers could no longer hold her attention. She got into fights, abused her seniors and flirted with what seemed to me to be the wrong crowd on the council estate where she lived.

My lecturing had no effect. I decided to send her to a private school. Her brothers and sister confronted me. I was not going to take their sister and transform her into a stuck-up little brat. They had all been to comprehensives: some did well, others hardly got a GCSE. She would make her way, they said. She had shown enough character to guarantee that. I surrendered.

She became pregnant at 15 and had a couple of brushes with the police. Although she did reasonably well in her GCSEs, her life appeared to be going nowhere. Now, with her child aged seven, she is training to be a teacher. The children were right and I was wrong. Even if she had become a factory worker, they tell me, she would have moved rapidly up the ranks. She is that kind of girl, strong and intelligent.

I am not offering a recipe, simply outlining an organic process that, if interfered with, can lead to disaster.

This brings me to Ryan Bell, the black teenager plucked out of the working classes - having alienated his teachers - and sent to Downside, the Catholic boarding school. Trevor Phillips, who as well as being a figure in politics runs a TV production company, sponsored him and arranged to film him for a year.

Ryan's successes were broadcast for all to learn from. Now he has been expelled, after a series of misdemeanours including a piss-up on vodka that landed him in hospital. Ryan's natural instinct for leadership took over once the cameras left; instead of being transformed into a public schoolboy, he transformed the children of the rich into his own image. So he had to go.

Trevor belongs to the black middle class, few in number, and lacking influence in the black community. The instinct of every class is to reproduce itself. Caribbean to the bone, Phillips sees education as the sole way out of crime and social deterioration. He wants comprehensives to adopt the ethos of public schools.

I am sure we will hear from Ryan again, if he is left alone. Many Caribbeans did well in English at school, but we did not all leave chanting: "The rain in Spain falls mainly on the plain." So there.