David Budge and Maureen O'Connor end their reports from the British Educational Research Association conference.
Some African-Caribbean teachers earn a reputation for being blunt to the point of brutality, but new research suggests that their bark is substantially worse than their bite.
Dr Christine Callender of Kingston University in Surrey, studied six black teachers at work in the classroom and found that they were adopting methods that are prevalent in the Caribbean.
Black teachers appeared to be more willing than their white colleagues to praise children in front of their classmates, but they also used several reprimanding strategies, ranging from what she terms "directness" to "shaming and truth-telling". She told the conference that black child-rearing practices are often designed to develop toughness and self-sufficiency and that children perceive parental discipline not as rejection but as the actions of a caring adult.
Dr Callender, who said that shaming is a highly developed and lively aspect of black oral culture, heard one woman teacher tell a pupil: "Cherylle, shut up. All you do is sit and chat. You can't do anything yet you talk all the time. How are you going to learn if you don't listen? Everybody in the class is more advanced than you. If you want to remain like that, continue."
One of the two black male teachers adopted an equally extreme strategy. He told Dr Callender: "I hit them hard, knock them down and then build them up again. The white teachers get very nervous when I say things like 'remember you're black' but the pupils respond in a positive way."
The other male teacher adopted much the same approach. "One of the values that has to be instilled in them is that you have to work harder than the whites, " he said. "This is the reality, so I tend to be a little more hard with the blacks than the whites."
According to Dr Callender, such tactics provide valuable support for some black children and none of the white children in the classes she observed had raised their teachers' behaviour as"an issue for concern".
But she acknowledged that there were some potential drawbacks. "Although strategies such as truth-telling have emancipatory intentions, there are some children, including those of African-Caribbean heritage, who would interpret it as a personal attack," she said. "It is clear, therefore, that the meanings attached to routines such as this need to be made more explicit."
Furthermore, the fact that black teachers were often good disciplinarians who could deal with difficult black pupils and their parents could rebound on them.
"Black teachers are in danger of being viewed as 'professional ethnics' and, as a result, are not recognised for their curriculum expertise," she said.
Cultural Style in Multi-ethnic Classrooms - The Case of African-Caribbean Teachers and Pupils, Christine Callender, The School of Education, Kingston University.