Life is full of choices, sometimes too many choices.

Should you buy the SUV or the gas-saving hybrid car? Should you have the artery-clogging cheeseburger or the lean turkey sandwich? Sometimes we make the "right" choices, but other times we make the choices of fools. Oddly enough, those foolish choices don’t usually bother us for long. Instead, they are quickly rationalized until the guilt goes away.

Why are humans so good at fooling themselves?

Our brains, then, weren't so much designed to make choices as to pretend, no matter what, that we made the right choices. The goal seems to be mental peace; as we all know too well, the time from bad choice to righteousness is very uncomfortable and so the sooner we justify our decisions, the better.

This kind of shilly-shallying is, in fact, so prevalent in human behavior that it must have some evolutionary basis. That is, it must be advantageous. Embarrassing and annoying, but advantageous. How?