State school graduates do better at university than private school graduates with the same end-of-school tertiary entrance score. That’s the clear finding in a number of Australian studies since the 1980s (here, here, here and here), and in England since the 1990s (here, here, and here).

The Australian research compared academic results at the end of first year at particular universities for cohorts whose entry was based on tertiary entrance scores (now ATAR) for the previous year in the same state. The most recent English research tracked all students who completed the end-of-school A-levels and went directly on to complete a full-time four-year degree course.

The differences between graduates of state and private schools were substantial (though less pronounced among those who did very well at university). The Australian research found that, on average, graduates of state schools received the same marks at the end of first-year university as graduates of private schools who had tertiary entrance scores around three to six points higher.

The English research found that at each A-level standard, on average around 7 percentage points more graduates of state schools than graduates of private schools received first or second-class, first division (upper second) honours.

Research in both Australia and England also found that with the same tertiary entrance scores:

graduates of co-educational schools tend to do better than graduates of single-sex schools

graduates of lower-fee private schools (in Australia, Catholic schools) tend to do better than graduates of higher-fee private schools (in Australia, independent schools)

graduates of schools with lower average tertiary entrance scores tend to do better than graduates of schools with higher average tertiary entrance scores

graduates of (English) state comprehensive schools do better (to a small extent) than graduates of state selective schools.

The general finding is that graduates of non-elite and co-educational schools do better at university than graduates of socially and academically elite and single-sex schools who achieved the same tertiary entrance score.

So what can explain this difference?

There are no definitive explanations for these findings, though there is some attempt in the literature, some indicative data, and much informed speculation. And there is, of course, great variation among individual students – and among schools, universities and university courses.

Explanations tend to focus on aspects of secondary schooling and on students’ effort levels at university (associated with their cultures and aspirations), and any may be involved in particular cases:

Preparation for the end-of-school assessments in private schools, relative to state schools, boosts tertiary entrance results above “underlying ability”, and graduates regress to “underlying ability” level at university.

Preparation for life and learning beyond school in private schools (and single-sex schools) relative to state schools (and co-educational schools) is poor, resulting in university performance below “underlying ability”.

Graduates of private schools make less effort at university because of perceived long-term advantages of their secondary schooling and other socio-cultural reasons.

It appears a reasonable assumption that tertiary entrance scores are boosted by a better quality of education at high fee private schools. Fee-based resources several times greater than those of state schools can fund smaller classes and other ways to enhance learning. In addition, selection and exclusion practices can ensure an academic atmosphere not disturbed by disruptive, difficult-to-teach students, or even students without high academic aspirations.

However, there appears to be contrary evidence: state school students tend to do better in NAPLAN tests than private school students at schools of similar socio-economic status (especially at higher socio-economic levels), according to data on the My School website analysed by researchers Bernie Shepherd and Chris Bonnor for a forthcoming publication.

Thus other explanations are likely. One involves a narrow focus on tertiary entrance results at many elite schools. Tertiary entrance results are a central aspect of the status and marketing of high-fee private schools – supported by high-visibility league tables and human interest stories in the media. High pressure, close supervision and narrowly defined learning leave little room for independent, self-motivated learning, and developing the personal and social skills required for success at university.

Single-sex school cultures and practices may not prepare students well for university life. This is hinted at in the literature, but was “obvious” for a recent university graduate I spoke to who attended both single-sex and co-educational secondary schools and said many single-sex school graduates “do not learn to socialise at school, and when they get to uni they just party”.

Other possible explanations relate to cultural class assumptions around success and entitlement. Some private school graduates may have an explicit belief (whether reasonable or not) that just having attended such an elite school will lead to employment advantages after university. Thus the incentive to work hard at university is diminished.

Some may have a less conscious belief that they have innate superior intelligence that will get them though university without much additional effort. This sense is not properly tested in the “hothouse” atmosphere of closely supervised elite schooling, but is found wanting in the more open society of university.

There may also be a lack of motivation for university among those from elite private schools where university is the norm. Those from state schools, where many different destinations are common, make a more deliberate choice for university.

What are the implications?

The government has set its sights on a highly differentiated fee and scholarship regime for higher education. Graduates of many universities are likely to have debts of over $100,000 for popular and socially important courses such as science, and debts of over $250,000 for longer courses such as veterinary science.

Universities with high-demand courses and high fees will need fairer criteria for access to all courses and for the awarding of all scholarships based on entry-level academic merit. This is not just a matter of justice for individuals, but also for our future as a well-educated, productive and fair society.

English education commentator Nick Morrison suggested that the disparity between state and private school graduates’ success at university

should provoke fee-paying schools to question whether they are doing all they can to equip students for university.

The Australian Financial Review recently urged people to “do the sums on the true cost of private schools”. It’s apparent that high private school fees may not be buying effective education. In the context of university debts upwards of $100,000, families should “do the sums” on comparable expenditure on schooling.