With every year that passes and the more observational experience I have, I've become convinced most people are afraid to think for themselves. I mean that exactly as it sounds. When they start to think in any way that is out of the scope of the allowable opinions they get nervous. Often they get angry when pushed to think in these ways. It is unsettling for them. I think "The Righteous Mind" does a fair job of explaining this but not fully. There is something deep in people that blocks them from free thought.