Exam success for pupils in Scotland's schools may have more to do with their parents than which school they attend, according to new research.

A study by Edinburgh University suggests there is little difference between exam pass rates at private and state schools if the parents are middle-class and well educated.

The private sector has questioned the figures, arguing there is more to an independent schooling than passing exams.

Professor Lindsay Paterson, one of Scotland's leading authorities on education policy, analysed government figures.

Prof Paterson: "Enormous impact of parents"

The so-called league tables of exam pass rates consistently show independent schools outperforming state comprehensives.

But Edinburgh University's professor of educational policy told Newsnight Scotland that his study showed the enormous importance of parents in their children's education.

He said: "The influence that parents have on how their children progress is far greater than the influence of schools, after taking into account what they will be able to provide for their children regardless of which school that child attends."

Prof Paterson first looked at Standard grade passes.

More passes

In independent schools, 95% of pupils from middle-class families passed five or more Standard Grades at levels one to three.

The pass rate for the same kind of pupils in the state sector was just 2% lower at 93%.

At Higher level, almost three-quarters (74%) of the sample in independent schools got three or more passes.

The influence that parents have on how their children progress is far greater than the influence of schools

Prof Paterson

However, similar pupils in state schools were just a shade behind, with more than seven out of 10 (71%) reaching the same standard.

At five Highers or more passed, the gap only gets a little wider - 60% in independent schools, 55% in the state sector.

Prof Paterson said: "It does seem from these surveys that for children of well-educated middle class parents they will do almost as well in a good quality public sector school as they would by going to the private sector.

"I think that what therefore comes across from that is that a parent thinking about possibly sending their child to an independent school might be better advised to stick with the local comprehensive school.

"And they could use any spare money to provide, for example, extra tuition, special classes in music, that kind of thing."

The independent sector said the main reasons for parents' choosing independent schools were smaller class sizes and individual attention given to pupils.

'Old data'

The overall standard of education, a perception that independent schools best realised a child's potential and a wider and fuller curriculum were also given as reasons for private education.

The Scottish Conservatives' education spokesman, Brian Monteith, argued that the research was "essentially worthless" because it was based on old data which was not sufficiently detailed.

"I do agree with Professor Paterson that the commitment and involvement of parents is the most important factor in the educational attainment of pupils, but this is hardly groundbreaking," he said.

"To go one step further and claim that state schools produce the same outcomes as independent schools for children of educated middle class parents is an entirely baseless assertion."