Family wealth has MORE of an impact than neonatal intelligence. Born rich, stay rich. Born poor, stay poor. Born average, stay average. That's my point.
Of your 100 surgeons and 100 manual workers... yes, you need a degree of above average intelligence to become a surgeon. And, of 10,000 upper middle class, privileged kids, maybe those 100 surgeons were the ones that had that intelligence. But of the manual workers, if you took them and slotted them in with 10,000 of THIER working class peers, what number would also have that requisite above average intelligence? I'd say 100. They just don't get the chance. We're equally bright across class divides but some people don't get the same chances as others.
I think people are quick to assume that poor or disadvantaged people are a bit thick, and therefore they deserve the status they have. It's simply not true. Maybe not well read, or educated, or engaged, or cultivated, or even politicicised... because the chances never come for some. But not dim. Just ordinary human minds.
I am a professional with two degrees. I don't kid myself that I have a special intelligence that 'rednecks' do not. I am very average and I had good opportunities, starting with a full bookcase in my home and disposable income in my mum's pocket. That's it.