Before writing an intemperate article using terms such as "scandalous", "prejudice" and "hunch", it would have been wise if Cambridge historian Simon Szreter had checked a few sources. He would have found convincing evidence that research has been undertaken and the situation regarding the award of A-level grades is the opposite of that which he postulates.
Mathematics, the sciences and foreign languages tend to be severely graded. Generally more able pupils enrol for these subjects yet they come out with the same or lower grades than those obtained by less able pupils taking less severely graded subjects. The School Curriculum and Assessment Authority can provide the research details in a report by Fitz-Gibbon and Vincent, 1994.
Carol Taylor Fitz-Gibbon Curriculum, Evaluation and Management Centre University of Newcastle upon Tyne.