YOU can't fatten a pig by weighing it.

So goes the mantra of educationalists who believe too many exams spoil the pupil. Earlier this week, The Herald published a report by left-of-centre think-tank The Reid Foundation which called for the current system of Scottish school exams to be scrapped.

Instead, the report argues, a single exit qualification, perhaps along the lines of the international baccalaureate, should be introduced.

Brian Boyd, emeritus professor of education at Strathclyde University in Glasgow, who wrote the paper, made the suggestion because he believes an over-reliance on testing is ­undermining the education system - with university entry requirements just as culpable as schools for the exams "treadmill" faced by pupils.

"Examinations dominate secondary schools. They influence the shape of the school day, they are the starting point of the timetable and ... they dictate how many subjects a pupil may study," his report states. "They distort the curriculum, they narrow the focus of learning and, as the exam diet draws closer ... the stress is often palpable."

His report comes at a time of ­significant change in Scottish school education with the introduction of the Curriculum for Excellence (CfE).

Part of the rationale for CfE was to reduce assessment for pupils and ensure they learn a broader range of skills, but many schools have proved resistant.

Rather than giving greater flexibility to pupils to sit exams over a longer period of time or to skip some altogether, schools have largely replaced one set of qualifications with another - with pupils sitting Nationals at exactly the same time as they would have sat Standard Grades last year.

In a large part that is because many schools and teachers have a vested interest in the status quo. They are seen as successful because of their ability to get pupils to pass exams, so why should they change?

Parents are also painted as supporters of the status quo because they flock to schools in middle-class areas which top the exam league tables - even though that is often because of the affluent catchment areas they serve.

In a society where exams are seen as the passport to higher education or a good job such attitudes are hard to argue with, but so often universities and businesses complain that the pupils who arrive with fistfuls of Highers are lacking the real skills they require.

In fact, Mr Boyd argues the commonly held idea that parents are resistant to change is not played out by the facts.

"Do they want education to help create a fairer, more just society ... or are they motivated only by narrow self-interest?" he asks.

"When parents are asked for their views, they are capable of taking a broad view of education and are capable of participating in debate about fundamental issues affecting not simply their own child, but children as a whole."

If it is true, as Mr Boyd suggests, that pupils can currently achieve success in Highers with the minimum of understanding, then surely parents would want something better?