Sunderland University wants to become more “career-focused”. So it is to shut down all its language, politics and history courses and promote instead degrees that “align with particular employment sectors”. It’s an illustration of what happens when universities turn into businesses, and their ethos is defined by the market. It’s also symbolic of the divisions that now rend Britain’s social fabric.

Just as Sunderland was announcing its makeover, the Sutton Trust was publishing a report on the geography of social mobility. The report, Elites in the UK: Pulling Away?, confirmed that social mobility has declined in recent decades. It showed that the majority of the socially mobile have built their careers close to home while the majority of those who come from privileged backgrounds tend to move greater distances in search of upward mobility. London is barely open to people from working-class backgrounds – three-quarters of those who move to London to access good jobs are already part of the elite.

None of this should come as a surprise. The distinctive character of London has long been known. There has been growing recognition, too, that the issue is not simply one of London versus the rest of the country, but also a broader divide between big cities and smaller towns.

From education to health, from transport to culture, the thinktank Centre for Towns argues, those living in cities have advantages and opportunities often denied to those in towns. If you live in a small town, you’re likely to have to travel almost three times as far to reach a hospital, and almost twice as far to see a GP or dentist as someone in a large city. There will probably be fewer pubs, a more rundown high street and less accessible public transport. Of course, the experience of living in a small town is different in affluent areas of Oxfordshire or Surrey than in Wales or the north-east. And those without money or jobs are far less able to take advantage of the opportunities of a city than those with affluence.

Nevertheless, city life seems to mitigate the impact of class and poverty. Consider, for instance, children receiving free school meals (FSM), a proxy for poverty. In England as a whole, fewer than a quarter of 15-year-olds receiving FSM go on to university, as compared with 41% of non-FSM children. In inner London, however, that gap is much smaller – 45% of FSM children go on to university, compared with 53% of non-FSM children. If you are a poor child in London, you have a better chance of attending university than if you are not poor but from outside London.

The city effect could also explain what might otherwise seem counter-intuitive results for minority children. There has been much discussion about the lack of black students at Oxbridge. When it comes to universities as a whole, though, black students are overrepresented. Black people make up 3% of the UK population – but 8% of university students, and 4% of students in the Russell Group of top universities. Much of this might be related to black communities being concentrated in large cities, especially London, where they make up 13.3% of the population.

There is a complex relationship in Britain between class, race and geography

All this explains why Sunderland University’s decision is so depressing. It’s a university that, like many in the north-east, caters to students from the local area. Its repurposing seems to suggest that the study of the humanities should be reserved for the children of the rich, who can afford to move, while local working-class students should be confined to “vocational” subjects. Existing divisions will only deepen.

There is a complex relationship in Britain between class, race and geography. But the language we use to discuss these issues, and the categories we employ, often ignores that complexity. The postmortem into Labour’s electoral defeat, for instance, has pit those who argue that the party needs to ignore metropolitan liberals and become more socially conservative to address the needs of the “traditional working class” against those who suggest that Labour should give up on its traditional supporters and concentrate instead on the “professional middle classes, together with the young, and black and minority ethnic voters, who are [now] Labour’s base”. It’s a debate that ignores both political needs and sociological realities.

The current debate over white privilege is equally depressing, polarised as it is between those who insist that racism is no longer an issue in Britain and those who imagine that all white people, whether shelf-stackers or company bosses, possess “privilege”.

It would seem that it’s not just potential students in Sunderland who are being deprived of deeper thinking into history and politics.

• This article was amended on 31 January 2020 to remove an ambiguous reference to “sociology”. That programme will continue to be offered at Sunderland University.

• Kenan Malik is an Observer columnist