[O]ur attitudes are shaped much more by our social groups than they are by facts on the ground. We are not great reasoners. Most people don't like to think at all, or like to think as little as possible. And by most, I mean roughly 70 percent of the population. Even the rest seem to devote a lot of their resources to justifying beliefs that they want to hold, as opposed to forming credible beliefs based only on fact. […]
One danger is that if I think I understand because the people around me think they understand, and the people around me all think they understand because the people around them all think they understand, then it turns out we can all have this strong sense of understanding even though no one really has any idea what they're talking about.
