Girls consistently outperformed boys in reading, grammar and maths. And with every year, the gap between girls' and boys' achievement increased.
Then the First World War broke out.
Archivists at the Printers' Charitable Corporation have just uncovered records detailing the exam results of large numbers of printers' children, educated between 1900 and 1923. And, with the exception of occasional references to tubercular 13-year-olds called Herbert, the contents of these records prove uncannily familiar to modern-day readers.
In 1900, girls were already outperforming boys in a range of subjects. In grammar exams, for example, girls scored an average of 94 per cent, compared to the boys' 52 per cent. Their reading scores were also notably better than the boys': 89 per cent, compared with boys' 84 per cent.
Only in two subjects did turn-of-the-century boys outperform their female classmates: dictation and composition. The difference was greatest in composition, where boys scored an average of 91 per cent, compared with girls' 76 per cent.
Becky Francis, professor of education at Roehampton University, is unsurprised. "The gender gap is not a new phenomenon, despite current gnashing of teeth over boys' underachievement," she said. "Throughout the last century - and even before - what remains consistent is boys' continuous underachievement in literacy and language."
Similarly, the corporation's long-term records of pupil performance could be taken straight from today's newspapers. Girls' achievement rose significantly over the 23 years during which results were measured. Boys' performance, meanwhile, remained stable, creating an ever-increasing gender gap.
By 1923 girls were outperforming boys by an average of 24 per cent in composition, and by 25 per cent in dictation. In arithmetic, which in 1900 saw boys and girls almost neck and neck, girls' grades were 24 per cent higher than boys'.
Stephen Gilbert, chief executive of the Printers' Charitable Corporation, points out that girls' improvement increased dramatically at the end of the First World War.
"If you look back at that period, education for women was considered a waste of time," he said. "But because of the carnage in the trenches, there was a huge shortage in terms of the numbers of men. Educated women became valued in the marketplace."
Professor Francis agrees that social expectations play a key role in determining pupils' achievement. "Elements of the literacy and language curriculum seem to be constructed as feminine: careful handwriting, emotional engagement in poetry and novels," she said. "They're seen as out of keeping with current constructions of masculinity, and therefore difficult for boys to keep up."
And society also influences the way in which pupils' achievements are perceived. Jacob Middleton, a historian at Birkbeck College, University of London, points out that girls have outperformed boys since the introduction of school exams in the 1870s.
"In the past, people didn't see any reason to be particularly bothered by it," he said. "Women weren't seen as potential workers.
"But there's been a massive shift, and women are now expected to perform in education and in work. They're competing with men, and that transforms expectations."