We Don't Have to Make Sense All The Time; Neither Do Other Peopleyesterday about the practical living-your-life problems with assuming other people are always acting intentionally with their own self-interest in mind. But there's a scientific reason for thinking that such systems (and I'm looking at you, evolutionary psychology and behavioral economics) have a fundamental flaw.
One of the biggest misunderstandings about evolution is the idea that "evolved" means "best" or "most efficient". It's largely the fault of the phrase "survival of the fittest".
Folks interpret that small clause as an absolute maxim. It's why people think they're "better" or "more" evolved than other species. But really, that pithy little phrase should be written like this:
"Survival of the best-adapted organism to a particular environment, among the possible competitors at that time."
That's a very, very different phrase. Is a cheetah "more" evolved than a penguin? Depends on whether that animal is on the African savanna or Antarctic ice fields.1
But even in the right environment, an organism doesn't have to be perfect or "the best". It just has to be better than the other organisms competing with it. As long as you're not falling behind the competition, you can have all sorts of problems, design flaws, and other issues.
And that's what evolutionary psychology, objectivism, and behavioral economics all miss about our psyche.
We don't have to make sense all of the time. We just have to make enough sense that we don't completely pooch ourselves.
And that's the only measure that counts. As long as we are rational enough to get by, the rest can be all kinds of crazy cruft. Superstitions. Horoscopes. Religions. Belief in the goodness of mankind. Belief in the evil of mankind. The specific kind of crazy believe or maladapted thought processes doesn't matter (remember Hanlon's - or Heinlein's - Law) - it all falls in the same category. It's just noise to something like game theory - but it's a very important and human part of our experience, and something we cannot afford to ignore.
1Homo sapiens cheats. We use tools to essentially perform "on the fly" adaptation to an environment.