Earlier quoted context omitted.
First point: I live in Scandinavia. Poor people are just as dumb here as in USA, but we take better care of them. USA assumes that poor people should be able to take care of themselves, which doesn't work. Taking care of them doesn't make them smarter, but it makes their lives better which is the point.
That's not about smartness or dumbness, though. I don't think intelligence is correlated with poverty much, but poverty is additional difficulty, so they have to work harder for the same thing as someone who isn't poor.
This is contrary to the available science. IQ and earnings are strongly correlated.