THREE-QUARTERS of Northern Ireland primary principals believe pupils receive private tuition to help them to win grammar school places, according to research commissioned by Ulster's education department.
But, writes Sarah Cassidy, working-class parents often do not believe their children should aim for grammar schools, telling researchers they were "not for the likes of us".
Inner-city parents were also much less likely to provide extra coaching for their children, partly because of the costs involved.
The research, led by academics from Queen's University Belfast, covered all primaries in Northern Ireland.
It will be considered by Government officials and the Northern Ireland Assembly to decide whether Ulster's selective system should continue.
Northern Ireland's secondary schools have been split between grammars and secondary moderns for more than 50 years.
Tony Gallagher, professor of education at Queen's University, said: "One strand of our study looks at the impact coaching might have on the quality of the results of the 11-plus. One of our hypotheses was that if a socio-economically disadvantaged community has less access to coaching then it might exacerbate some of the social inequities of the system."
The interim findings of the study, due to be published early next year, found that most primary teachers were opposed to private coaching, saying it put too much pressure on children.
Parents did not support out-of-school tuition whole-heartedly but felt it was expected of them and that it would give their children "that little edge" in the competition for a secondary place.
Schools also admitted that they coached children for the tests, on average for one or two days a week. Nearly one-third of principals strongly agreed with in-school coaching, while a quarter disagreed.
A spokesman for the Department of Education in Northern Ireland said: "It is hoped the report will inform and serve as a catalyst for a wider public debate on the most appropriate form of secondary education for Northern Ireland. Following that debate, it will be a matter for government or any new Assembly to consider future arrangements for secondary education."