They won’t admit it, but there is a pervasive idea among some Londoners, particularly the adopted ones, that the cleverest people from the north of England all end up in the capital, like particularly urbane moths drawn to the irresistible bright lights of the big city.

Exiled northerners are terrible for it, flaunting their Lancastrian or Yorkshire credentials whenever there is an opportunity, wanging on about the Wigans and Bradfords they left behind at least 20 years ago.

The truth, of course, is they now make only annual, fleeting visits to see family members who lacked the wherewithal to get out themselves. In they sweep, silently despairing of getting a good flat white north of Walthamstow, scarcely able to believe the dearth of Pret a Mangers.

The Brexit result confirmed everything these people think about England’s upper half. Idiots, they thought, when Sunderland returned the first decisive Brexit vote. Hasn’t it occurred to those halfwits on Wearside that Nissan might pull out from the Sunderland plant where they employ 7,000 locals? Are they too stupid to foresee the knock-on effect for the 40,000 jobs in the wider UK supply chain?

It is the same snobbery that caused an eminent art critic to recently opine on Radio 4 that he hadn’t seen a few Caravaggios being shown off in a London exhibition – because they had been “hidden away in places like Hull and Preston”. They might as well have been on the moon, though he would no doubt have seen them had they been hung in Florence or Paris.

The mantra goes that those who voted to leave are those who have the most to lose when Britain exits the European Union. But to say that out loud implies that anyone who voted that way hadn’t bothered to think through the consequences. It is a pretty insulting supposition, as a report from the Institute for Public Policy Research North rightly notes today.

“Of course we did! We knew both sides of the argument,” the retired nurse in Sunderland told me. “They said we would go right to the bottom of the heap, but it hasn’t happened. It might happen. We might go through a rough patch. But we will get through it in two or three years’ time, and I think it’s worth it.”

From where she was sitting, things looked pretty good. Nissan had not only decided to stay in the north-east but had vowed to build two new models in the Washington plant, a few miles out of Sunderland, having extracted opaque assurances from the government that no trade barriers would affect their business, which exports 80% of the 500,000 cars produced each year. Even the local Labour councillor for Washington North voted leave, telling me that globalisation had failed his constituents on the doorstep of Europe’s most productive car plant.

I went to visit AV Dawson, a logistics company in the Nissan supply chain, which lost a string of multimillion-pound, 15-year contracts in the immediate aftermath of the referendum result. Most of the workers receiving and delivering steel to make car bonnets at the Sunderland Nissan plant voted to leave. And of course they considered whether Nissan was likely to up sticks. Yet when Nissan’s boss made threats to leave, back in late September, they didn’t take it seriously.

“In my personal opinion it was scaremongering,” a thoughtful 24-year-old crane operator told me. “I always thought that the quality of work that we can produce in England is much greater than anywhere else. So if they really want top quality, they are not going to go over just a couple of quid.” He felt buoyed by the result. “It did make you feel like you counted, this time around,” he said.

Giving evidence in Sunderland to the new select committee on exiting the European Union on Thursday, Ross Smith, policy director of the North East Chamber of Commerce, said the media needed to start to present a more nuanced view of the consequences of Brexit. There’s the view that Brexit will either be a “glorious triumph” or a “complete disaster”, he said: “The reality is that it will probably be somewhere in between.”

Instead of sneering, people need to understand why most of the north, apart from some inner cities and a few wealthy rural exceptions, voted to leave. Could it be that they are fed up with receiving crumbs when London and the south-east get whole loaves? Spending on schools, arts, transport infrastructure and so much more is vastly weighted in London’s favour.

Many northerners look at London getting £50m for a frivolous garden bridge – as well as £4.6bn for Crossrail, more than will be spent on transport in the whole of the north during the same period, according to the IPPR – while they commute on juddering “pacer” trains, literally bus chassis welded on to ancient wheelbases. We keep hearing about the possibility of a “crossrail for the north”, improving east-west links. But what did the chancellor really trumpet in his autumn statement? A new “Varsity” rail line between … Oxford and Cambridge. If there is any track left over when they’re finished, perhaps they’ll send it up north.