FORTY per cent of girls studying for the Leaving Cert spend at least four hours a night at the books.
And more than half of these girls complain that they feel "constantly under strain" according to the latest ESRI report.
Meanwhile, only 30 per cent of male students do as much study as their female counterparts.
Students who spent more time on homework and study in sixth year also got higher grades. This was particularly true for those spending three to four hours a night on homework, but the report also found that those who spend more than four hours studying did not have any greater advantage.
In sixth year, high-performance students tended to focus on what was likely to "come up" on an exam paper and they expressed frustration with teachers who did not focus on this type of preparation.
The report by Emer Smyth, Joanne Banks and Emma Calvert concluded that the current Leaving Cert model tended to focus both teachers and students on covering the course.
The research by the Economic and Social Research Institute concludes that the Leaving Cert "narrows the range of student learning experiences" and should be reassessed.
The findings were being discussed today at a conference on possible changes to the Leaving Cert and the college admission system.
They have been drawn from a study that tracked 900 students in 12 schools right through second-level.
The study showed that students who performed well in the Junior Cert would perform equally well in the Leaving Cert.
Almost half of all Leaving Cert students are having private grinds outside school, and in middle class areas the figure jumps to 70pc.
Maths was the most popular grind subject, following by French and then Irish.
In one middle class school, almost 70 per cent of students were getting extra tuition, compared with just 10 per cent in one school in a working-class area.