Many black pupils believe teachers think they are "stupid" and lack ambition, according to an evaluation of the Aiming High project, designed to promote black achievement in schools.
The project, in 100 English schools since 2003, has boosted black achievement but failed to close the gap in GCSE results. Forty-five per cent of black pupils in England now achieve five top GCSEs, compared with a national average of 55 per cent.
Interviews with more than 100 pupils at 10 multi-ethnic schools suggested they believed teachers' prejudices were a major factor.
"The teacher tells you you are stupid to your face. They say, 'Oh you're not going to achieve anything anyway, so there's no point helping you.'"
said one Year 8 girl.
"A lot of us will see that other people are favoured a bit more," said a Year 9 boy. "If you confront the teacher about it, obviously they're not going to say, 'Yes, I favour this colour people.'"
Other pupils complained that teachers had an attitude of "Oh, she's black innit, she's got no ambition" and that teachers expected "black boys to do bad". Negative comments and lack of attention were two chief concerns.
The interviewers found that teachers had a tendency to stigmatise and blame Afro-Caribbean culture for underachievement. One head of English described black boys as "stuck in a rut".
Aiming High, which provides training, mentoring and extra staff at a cost of pound;1.7m a year, has raised performance among black pupils at key stages 3 and 4 by several percentage points.
St Joseph's academy in Lewisham, south London, is working hard to raise its pupils' aspirations. Gibril Tonteh, 15, who wants to be a surgeon, said:
"People have had high expectations of me since primary school." He added that the smarter dress code at the Catholic boys' secondary, where 90 per cent of pupils are of Afro-Carribbean origin, had improved behaviour. "Back in the old days, kids used to come in with their hair in a mess, wearing trainers or jeans," he said. "Now they're looking in the mirrors and checking themselves out."
Jason Dacres has also taken advantage of the new rule allowing those in Years 10 and 11 to wear suits with coloured ties and shirts. "People respect you more if you're in a suit," he said.
Liz Lewis, former head of St Joseph's, and now managing its transformation into St Matthew's academy, said:"Everything we do is about aiming high. The raw talent of the boys is enormous."