As a former science teacher, it's been my experience that even stupid people can understand science if the topic is explained the right way. When people "don't get it", it's because they're too lazy to think. One of my biggest knocks against religion is that it pretends to explain events as being (untestable) 'miracles'. People who are to lazy to ask why are usually the ones who consider themselves the most adherent to a religion. The less they need to think, the more they think themselves to be correct (because of their beliefs)... and then you end up with public schools teaching Creationism alongside Evolution [Yeah... I'm talkin' about you, Texas...]

Most there flunk their own tests. Non believers do better in tests about religious faith than followers.