Kevin Browne, a professor of family and forensic psychology who works at Glenthorne Young Offenders Institution in Birmingham, told the conference that most young offenders have suffered emotional and usually physical abuse.
They have often been in care - some with as many as 32 placements. If these children then disrupt classes, he argued, they need help and not exclusion.
George Varnava, a former headteachers' leader who recently launched a Checkpoints scheme to cut down violence in schools, pointed out the conflicting demands on schools: zero tolerance of violent behaviour, the need to nurture all pupils and to cut exclusions by a third by 2002 - and all without extra funding.
The same desensitisation that makes violence "cool" for damaged young people, also cuts them off from learning, said Professor Browne.
At the very least, he said, we should restrict the common practice of entertaining young offenders with violent videos.
His plea was echoed by James Ferman, former head of the British Board of Film Classification, who expressed concern at the addictive way some young people watched endless replays of small snippets of violent video.