You can have a spiral of bad economic decisionmaking through demographic biases in natalism, but that's likely to be a product of cultural transmission, not of

You can have a spiral of bad economic decisionmaking through demographic biases in natalism, but that's likely to be a product of cultural transmission, not of any biological property of intelligence, which is mean-reverting and only dubiously and marginally correlated with genetic variation. Which is to say, you can make the point you're making without going out on a politically (and probably scientifically) incorrect limb.