Exam results from Edwardian England show that girls have been outperforming boys in the classroom for at least a century.
Radio New Zealand's education correspondent reports British archivists have uncovered records of a large number of children from 1900 to 1923, that show girls did better than boys in a range of subjects.
In one grammar exam in 1900, girls scored an average of 94% compared to 52% by boys.
New Zealand educationalists who've studied boys' education aren't surprised.
But they say the gaps, particularly in literacy-based subjects, can't be ignored, just because they have always been there.
Waitaki Boys High School rector Paul Baker says if the gap at tertiary level continues at the current rate, two thirds of university students will be female within the next decade.