It's a bit more complicated. There's genetics and culture involved as well.
Getting a PhD takes brains, work and dedication. Certainly red state dwellers have poor work ethics which may be a throwback to slavery when everything was done for them by the slaves.
Red State dwellers pray to Jesus for the stuff they want instead of making it happen by working for it. It seems they forget to old adage, the Lord helps those who help themselves.
Ignorance is bliss to a red state rightie. Finding out that the earth is round, and not 5000 years old is something they don't want to know.
Give your average Republican voter a large gun collection, a gas guzzling truck, a carton of Marlboro cigarettes, Oxycontin, crystal meth, moonshine, pulled pork, right wing radio, a white robe and a dunce cap and a confederate battle flag and they're happier than a pig in shit.