I don't like him at all anymore, but Scott Adams presented a model in one of his books that I found very useful in terms of describing how people (all of us, according to the model) decide how they're going to think.

His argument is that, in a "Plato and the cave"-type framing, everyone is going through the world using a "filter." The goal here, he says, is not to believe you can be the one to break out and achieve direct objective truth, but to find the best filter to labor under.

Quoth Adams, the best filters are those that A) have high predictive value and B) make you relatively happy. And that these two things need to be kept in relative balance for a filter to be viable in a long term, societal sense.

Like I said, I don't really like him or a lot of his ideas anymore. But I think about this one a lot.