It is the "hidden scandal" of A-levels, the leader of one headteachers' union said last night. Shrewd pupils, aided by their teachers, are opting for "easier" subjects where they know they will stand a better chance of getting an A-grade pass.
Forget the annual argument over whether the exam had been "dumbed down", argued John Dunford, general secretary of the Secondary Heads Association. The big question that the Tomlinson inquiry into exam reform should face is how to ensure a common standard across all A-level subjects.
The "hidden scandal", Mr Dunford said, is shown in the rise in the number of students opting for subjects such as psychology (up 21.2 per cent this year), law (up 20.6 per cent) and media, film and television studies (up 19.9 per cent).
There is also a drop in entries for subjects perceived by teachers to be difficult. Physics is down 3 per cent, chemistry 1.5 per cent and biology 0.8 per cent. In languages, German is down 0.9 per cent and French 0.5 per cent - although the picture here is even more alarming at AS-level, where the number of candidates has dropped by 8.5 per cent and 3.2 per cent respectively.
"It is incredibly worrying," said Mr Dunford. "We need more maths, science and modern language students. It is totally bizarre that these are the hardest subjects at A-level.
"This is causing a vicious circle. It has been shown statistically that psychology is an easier exam than maths at A-level. Part of the remit of the Tomlinson committee should be to make sure all subjects are of a comparable standard."
Mr Dunford was accused last night of putting a different twist on the "A-levels are easier" row, denigrating the achievements of the 250,000 or so youngsters who will be receiving their results today.
In fact, he was just being honest. He pointed out that universities do not demand that A-level passes are in the subject to be studied at degree level - and teachers are therefore giving their students the best chance of success by suggesting subject options which they consider easier to pass.
His comments were seized on by the Conservatives. Damian Green, the shadow Education Secretary, said: "We need to ensure every A-level subject is regarded as of equal academic value and equally difficult."
Overall, this year's results - which reveal a record pass rate for the 21st year in succession - do actually show that the inexorable rise in results is beginning to bottom out. The overall pass rate went up 1.1 per cent from 94.3 per cent to 95.4 per cent, compared with a 4.5 per cent rise last year. The percentage of pupils gaining A-grade passes rose 0.9 per cent to 21.6 per cent.
Much of this year's increase is put down to the introduction of the new AS/A-level system, with students ditching those subjects they fail to shine in at AS-level and only continuing with those in which they have a reasonable chance of success.
Two further pieces of good news emerge from this year's results. The first is that the overall number of subject entries has risen - by 7 per cent at A-level and 3.6 per cent at AS-level - and at a faster rate than the age cohort. This could be interpreted as meaning that the Government's exhortations for more pupils to stay on at school after the age of 16 is paying dividends.
The second is the fact that Mike Tomlinson, the former chief schools inspector charged with ensuring there was no repeat of last year's fiasco, has given this summer's marking exercise a clean bill of health. According to John Milner, convenor of the Joint Council for General Qualifications, the umbrella group covering all exam boards, there were no disagreements between chief examiners and exam board chief executives over grade boundaries for this year's exams.