Boys have scored a higher proportion of A* grades than girls every year since 2012, and extended their lead over girls in 2013, 2014 and 2015.
But this year that trend has come to an end, with boys’ share of A* grades falling faster than girls’, causing the gap in top grades to fall from 0.9 percentage points to 0.8.
When A and A* grades are combined, girls outperform boys, but their lead has this year shrunk to just 0.3 percentage points, its lowest level for at least a decade.
However, girls have consistently been ahead by about one percentage point when all A* to E passes are counted.
Malcolm Trobe, interim general secretary of the Association of School and College Leaders, said this morning that the shift to a linear exams system, with little coursework and most or all marks coming from a final test, may partly explain the existence of a gap in top grades.
'Boys do better in one-off exams'
“Boys have tended to do better in one-off exam situations and girls traditionally have done better in coursework,” he said. He added that girls outperformed boys on the Extended Project Qualification (EPQ), a project-based qualification favoured by many universities.
Mr Trobe also said the subjects which tended to award the highest proportions of A*s, such as physics, were generally taken by a far higher number of boys than girls.
Andrew Hall, chief executive of the exam board AQA, said the gender gap at A* was not brought about by the design of A-level exams.
“We do make sure when we design our assessments that they’re gender-neutral,” he said. “I think it would be unfair to say that the exams system favours boys or girls.”