‘Does this control for IQ?’ This was the question libertarian commentator Toby Young tweeted to us when the Social Mobility Commission (SMC) published the first part of our class pay gap research in 2017. It was a fairly predictable response. Young has written extensively about the relationship between cognitive ability and life outcomes, and has never disguised his view that IQ is both higher among the socially advantaged and tends to be passed between generations. Reading between the lines, Young’s tweet betrayed a certain scepticism about our findings so far. Yes, there may be a class pay gap, but this is probably driven by entirely legitimate differences in intelligence, he appeared to suggest. Young is not necessarily alone in this view. The US political scientist Charles Murray has long made similar arguments about the association between IQ and race, and more recently authored Coming apart, which blames the travails of the white working class in the US on their purported lower cognitive abilities. Back in the UK, former Foreign Secretary Boris Johnson has also drawn on these arguments, arguing that economic inequality is the ‘inevitable’ by-product of ‘human beings who are already very far from equal in raw ability, if not spiritual worth’.

These views may seem a little extreme. Certainly, empirical research connecting social mobility, intelligence and genetics is highly disputed. But we start this chapter with such provocations to make a broader point. While the class pay gap uncovered in Chapter Two is striking, it is important not to jump to the conclusion that it is driven entirely by class prejudice and discrimination. In fact, many readers probably spent the last chapter generating their own explanations for the class pay gap; maybe working-class people are simply younger on average than those from privileged backgrounds and therefore less far along in their careers? Or perhaps the privileged have higher rates of educational attainment and are earning more based on superior credentials? Maybe they just work harder, or perform better at work?

This chapter offers a direct dialogue with such sceptical readers. While we may not be able to measure something like IQ – or indeed wish to – it is not unreasonable to ask whether the class pay gap could be explained by other differences in what we often consider to be ‘merit’, such as educational attainment, job experience, level of training, or job performance.