State school pupils are likely to do better at university than independent school pupils with similar A-level results, according to a new study.
The findings will add to the debate around university admissions and whether applications from state school pupils should be favoured over those from independent school pupils.
Researchers Carmen Vidal Rodeiro and Nadir Zanini were investigating how effective the A* grade at A-level is as a predictor of university performance, and they found a divide between the performance of state and independent school students at university.
Dr Vidal Rodeiro said: "In both Russell and non-Russell Group universities, students from independent schools were less likely to achieve either a first class degree or at least an upper second class degree than students from comprehensive schools with similar prior attainment."
The Russell Group represents 24 leading UK universities.
The researchers note how previous research has suggested two reasons for the finding: private school students may have lower incentives to perform well at university and therefore may invest more effort in social life rather than academic work; or they may have been "coached" at school and subsequently struggle when they get to university.
The main focus of the research was into how effective the A* at A-level is as a predictor of university performance. The researchers found that the number of A* grades is a good predictor of achieving a first or at least an upper second degree in both Russell and non-Russell Group universities.
The researchers say their work highlights the importance of a grading system that allows greater differentiation among students, as it can be beneficial for effective and fair higher education admissions, particularly on the most oversubscribed courses.
Their work is published just two days after the authors of a report which said state school graduates get better degrees than independent school graduates announced that they had been wrong.
The Higher Education Funding Council for England said in September that 82% of graduates getting first class or upper-second class degrees in 2013-14 came from state schools compared with 73% from independent schools.
But it admitted to a "transposition error" - the numbers were the wrong way round. In fact, a greater proportion of independent school graduates were awarded a top degree than state school graduates.
The study published today was carried out by Cambridge Assessment, which operates and manages Cambridge University's three exam boards.
:: The role of the A* grade at A-level as a predictor of university performance in the United Kingdom by Carmen Vidal Rodeiro and Nadir Zanini is published in Vol. 41, No. 5, pp647-670 of the Oxford Review of Education 2015.