A former child soldier has urged teachers to be more aware of immigrant pupils' backgrounds and not to underestimate their potential.
Ishmael Beah, who was drawn into the civil war in Sierra Leone at the age of 13, said for some pupils the bar was "being set too low" by teachers who did not understand what they had been through.
Mr Beah, now 27, was given an AK-47 rifle and forced to fight with pro-government forces after his village was attacked. He says he does not know how many people he killed, partly because he was high on amphetamines and other drugs.
When he was eventually rescued from the military in 1996, he was sent to a rehabilitation centre and school in Freetown, but his whole attitude to learning had changed.
Speaking to 1,500 British heads and deputies at the National College for School Leadership's annual conference, he said: "I had gone from an 11-year-old boy with a love of Shakespeare to somebody who threw their schoolbooks at their teacher. Sometimes we would burn them or sell them to get money for bus trips into town."
After slowly becoming interested in learning again, he was invited to the US to attend high school and university. But he faced challenges there too, because of a lack of understanding about his background.
His American teachers expected him to type essays, a process that took him days when he could have completed them by hand in hours, and seemed baffled by his British spellings of English words. "They didn't understand where I was coming from," he said. "How many more immigrants around the world are going through the same thing?"
Schools needed to be more sensitive, he said, citing the refugee child who did not visit the school library - not out of laziness but because they did not realise such a thing could exist.
The Refugee Council estimated in 2003 that there are nearly 100,000 refugee children of compulsory school age in Britain.
Mr Beah said top universities needed to "take a chance" on students who might have lower grades because of disturbed backgrounds. He said: "If the universities are only giving opportunity to those who already have opportunity, we are not going to change anything at all."
Mr Beah's autobiography, A Long Way Gone, reached number one in the New York Times' bestseller list.
An Australian newspaper cast doubt on some dates and incidents in his story, but Unicef said it was "unaware" of any discrepancies and that it accurately reflected the life of a boy soldier.