I seriously doubt that any of them were less intelligent during their theist phase.
I was. But I was only, like, you know, nine or ten.
Democrats are better educated than republicans. And educated republicans are more likely to deny global warming than less educated republicans. We sort of need to be a little careful about thinking that education is an end all. It isn't if what people learn is a bunch of bull.
And though I am, of course, incredibly brilliant, I'm pretty sure I never made it to the status of "rich", so like most generalizations, they seldom apply all the time to all people. (Any that conclude that all people need air to breathe are probably universal. The rest, not so much.)
We atheists need to be especially careful not to fall prey to confirmation bias. We can't complain about it all the time if we use it amongst ourselves.