The problem with IQ is public schools imo. More specifically, the informal priority of public schools in the USA is to babysit the children of working parents who are too tired at the end of the day to ask their children what they learned in school.
And little do parents know that public schools are indoctrinating their children about federal government entitlement programs as opposed to being taught reading, writing, arithmetic and the federal government’s constitutionally limited powers.
When you are told how smart you are without actually having to achieve anything - why would you believe that you need to study anything. Obviously anyone who doesn’t think like you do should thereafter be called short sighted and ignorant. Thus, progressives proliferate.