Research by Edinburgh University's Centre for Educational Sociology based on the Scottish Young People's Survey has revealed that only 27 per cent of pupils who completed S4 in 1990 had been exposed to the curriculum's eight core areas.
Linda Croxford of the CES comments that this was an improvement on the position before the introduction in 1983 of the secondary curriculum framework, dubbed the "yellow peril" after its colour scheme and alleged inflexibility. But it was not the "total commitment" envisaged in the Munn committee's report of 1977.
All pupils took the compulsory modes of English, maths and science as well as social and environmental studies. But a quarter took no part in physical education or technological subjects in S3 and S4 and more than half missed out on creative and aesthetic activities, religious and moral education and foreign languages.
Dr Croxford found, however, that the compulsory study of English, maths and science had eradicated the gaps in take-up between boys and girls from different social backgrounds. Only 57 per cent of working-class girls studied science before 1983, for example, compared with 75 per cent of middle-class girls and 85 per cent of middle-class boys.
In other areas of the curriculum, gender, social class and type of school remained key influences. Only 26 per cent of working-class boys studied a language other than English compared with 50 per cent of middle-class boys and 73 per cent of middle-class girls. Technological activities had more appeal for working-class boys and girls.
Inequalities also persisted within modes of study, reinforcing the tendency for girls to take biology and boys to take physics. Working-class boys were more likely to pursue a general science course rather than biology, chemistry or physics. Sixty per cent of pupils in comprehensive schools studied just one science subject.
Dr Croxford warns that the greater priority independent schools give to academic subjects could put the broad curriculum under pressure in comprehensive schools as parent choice and secondary education "markets" create more specialisation and selection.
"There is a need to reaffirm the importance of equality of access to a broad-based Scottish curriculum," Dr Croxford declares.