Here's an example of how the right are in denial about inequality.Responding to a report in the Telegraph that the offspring of parents with a degree go on to earn more than the children of less educated parents, Tim Worstall says:

What we're seeing is that the children of the rich and or bright have higher incomes than the children of the not rich and not bright. And put that way it's not really all that surprising, is it?

This, though, is only part of the story. Heritability of ability can explain why the children of rich and bright parents go on to earn more than the children of the poor and not bright. But it cannot explain why this tendency is stronger in some countries - such as the UK and US - than in others.

We'd expect genetic heritability to be roughly equal across countries. But intergenerational mobility is not: it is lower in Germany than Finland, and lower still in the US and UK. Why should ability be more heritable in the UK than Germany and more heritable in Germany than Finland? Tim gives us no reason to think it is.

Instead, what we have here is the so-called Great Gatsby Curve - a cross-country correlation between inequality and intergenerational income mobility.

The research reported in the Telegraph - to which Tim does not link - tries to explain this. John Jerrim and Lindsey Macmillan show (pdf) that three things other than heritability are at work:

- The correlation between parental education and children's education is higher in more unequal countries. This is consistent with income inequality buying unequal access to education - for example, because rich parents in unequal countries buy private tuition.

- The returns to degrees are higher in unequal countries such as the UK and US than in more equal ones. This magnifies inequality in access to higher education.

- In the UK, children of uneducated parents earn less than the children of educated ones, even if they have the same qualifications. This suggests that inequality operates through channels other than education - for example by nepotism and cronyism excluding state school kids from top jobs.

It's clear from Jerrim and Macmillan's work that the retort "it's coz ability is heritable innit" is inadequate.

This, of course, matters. It means inequality is - to a greater extent that Tim admits - a social construct rather than an artefact of nature.

Now, I stress that I don't say this merely to have a pop at Tim; for the purposes of this blog, individuals matter only to the extent that they exemplify social or intellectual phenomena. I fear, based upon some of the comments to his piece and (some of) the right's past form, that he is exemplifying a more general habit - a kneejerk denial of the costs of inequality based upon glib appeals to human nature and a reluctance to actually engage with research.

Another thing: if I were a rightist trying to justify inequality, I'd argue instead simply that intergenerational immobility is no problem.