COMPREHENSIVE education has helped to achieve greater equality of opportunity among pupils since the system was introduced 50 years ago, researchers have found.

Higher levels of academic attainment and a more positive attitude to schooling are other notable achievements of the system, according to a new report.

However, academics from Edinburgh University argue elements of the current system, such as the introduction of parental choice through placing requests, while desirable to promote freedom, have reduced equality because they have a polarising effect in some communities.

"The introduction of parental choice eroded an important feature of the original comprehensive model: namely its basis in geographically defined communities," the researchers found.

And they called for more to be done if the values of comprehensive schooling were to fully benefit all of Scotland's children in the future with the biggest predictors of a child's academic success still parents' economic status and their levels of education.

Dr Cathy Howieson, a senior research fellow, said: "Comprehensive schooling has become part of the social fabric of Scotland with the system enjoying widespread support among parents and some 95 per cent of pupils attend comprehensive schools.

"Although the system has delivered many benefits, our book challenges policymakers to understand, and learn from, the lessons of the last 50 years."

The researchers conclude: "The concept of comprehensive education, especially when linked to the underlying values of liberty, equality and fraternity, is still a valuable concept for analysing, inspiring and guiding education systems and for exploring their possible future direction.

"Ideas of comprehensive education tend to have faded from policy debates in recent years in Scotland as elsewhere in the UK. The concept of comprehensive education should once more become a central theme of debates about the future of education."

Eileen Prior, executive director of the Scottish Parent Teacher Council (SPTC), backed calls for a fresh examination of the current system.

She said: “Comprehensive education has become ‘what we do’ in Scotland and very many of us would struggle to recall the system before comprehensive schooling began. For that reason, there is certainly a strong argument that we need to revisit and refresh the principles behind the system we have embraced, to ensure that these are front and centre of everything we do in all of our schools.”

Larry Flanagan, general secretary of the largest teachers’ union the EIS, said: "The principles of fairness and equality of opportunity are central to Scotland's comprehensive education system.

"There continues to be a very high level of support – from parents, teachers and others with an interest in education – for a Scottish comprehensive model that is designed to ensure that all young people, no matter what their background, have equal access to a quality educational experience that is appropriate for their own needs.

“There is little or no enthusiasm, within the EIS or elsewhere in the Scottish education community, for the ideologically-driven, market-orientated approach to education that continues to be promoted south of the border.”

A conference to discuss the impact of comprehensive schooling will be held at Edinburgh University this week - exactly 50 years on from the date of the Government circular that marked the abolition of selection at the end of primary school and heralded the introduction of comprehensive schools.

The book, entitled Everyone’s Future: Lessons from 50 years of Scottish Comprehensive Schooling, highlights diversity across social backgrounds as a key strength of the system - as well as a challenge.

It states: "The social and cultural diversity of a community-based comprehensive puts it in a very different position from that of an independent school.

"In the latter, parents have exercised an element of choice in placing their child there and have, in effect, already signed up to its particular culture - and the same is true to an extent of denominational schools within the state system.

"The community comprehensive has greater challenges - varying according to the social and cultural mix of the school - but it has greater opportunities to advance fraternity."