For education's arch-cynics it won't be terribly surprising - not at all. According to a major new Australian research project, if you remove all other mitigating factors, a private schooling makes no difference to educational outcome.
Taking into account variables such as wealth and parental education, researchers found that there was little statistical difference in the academic achievement of children from similar backgrounds whether they went to a private or a state-funded school.
Putting it bluntly, Luke Connelly, a member of the research team, explained: "It's not the type of school (that affects the results), it's the things that are being done for the child at home."
On the face of it, this finding should have two consequences, the first being that those of us whose parents paid for our education should stop feeling guilty about it. Secondly (and equally unlikely), the middle classes should shut the school fees savings account and spend it all on a skiing holiday.
"Ave Maria," parents should sing. Pull Little Tarquin out of Eton and bung him into the community college up the road! He'll follow Tarquin Snr to Cambridge whatever happens!
Of course, they won't. But that's not really the point, because, as we know, most parents who send their children to independent schools do so for reasons - accent and social networks, say - other than top grades. In their heart of hearts they know that Little Tarquin would probably do well at any school, because they wouldn't allow for any other outcome.
And thus they prove the Australian research right. It's not ideal marketing for private schools, but as long as they keep their heads down and keep banging on about class size, they're sure to be OK. Don't expect any influx of Tarquins into the state sector this side of another global financial meltdown.
But there's slightly more to this story than meets the eye. Take another look at Professor Connelly's quote. When he refers to "school type", he's actually talking about structure, not the private-state divide. The Australian research could just as easily be suggesting that how you structure your educational system doesn't make any difference to outcomes; systemic reform doesn't equal results.
So, at a very basic level, the UK government's desire to "share the DNA" of top private schools with local state schools is completely pointless.
The research is even more damning for swathes of the global education reform agenda, much of which is predicated on structure, especially school autonomy. In essence, charter schools, academies and the rest can go hang if we don't sort out wider societal problems.
But this is defeatist. Just because much research suggests that wider, largely economic, determinants are the over-riding influence on how well any given child will do at school, that doesn't mean the education system can give up.
No teacher, school leader or educationalist got into this frustrating business to resign themselves to the uselessness of it all. Keep innovating, keep trying, keep mixing it up - maybe even have a look at what they're up to in the expensive school next door - because every so often something works. It's magic when it does - and no amount of research can account for that.