It makes total sense to me this culture comes out of the UK. We still have this in our working class culture now which is why white boys are one of the lowest achieving groups here.

Basically in the past manual jobs were well paid. You could raise and house a large family on one. But the class structure was such that being too smart could lose you your job so that was something to be wary of. You'd tell your kids reading books or going to university "isn't for the likes of us". I know people in my generation who were told that.

The trouble is that while cultures always come out of a way to survive in a particular environment originally they are also self-perpetuating (see this joke http://imgur.com/a/qNG97zT) so they can exist long after their useful has expired even when they are actively harming their people. So now those same manual jobs are poorly paid, often there's only service jobs available and bosses want people to take initiative not just do what they're told so people following the old rules are setting their kids up for failure.

The world has moved on and you have to keep looking at what's really happening, not rely on the world view you've been taught or was right a decades ago.