Well, sure. Repeating other posts - but one of the most common examples is when an agent's beliefs are displayed to other agents. Imagine that all your associates think that there is a Christian god. This group includes all your prospective friends and mates. Do you tell them you are an agnostic/atheist - and that their views are not supported by the evidence? No, of course not! However, you had better not lie to them either - since most humans lie so poorly. The best thing to do is probably to believe their nonsense yourself.

Tim, that's an excellent argument for why rationality isn't always the winning strategy in real life. People have been saying this sort of thing all week, but it was your "most humans lie so poorly" comment that really made it click for me, especially in the context of evolutionary psychology.

I'd really like to hear one of the "rationalists should always win" people address this objection.

5steven046111yYou realize, of course, that under this policy everyone stays Christian forever.

The Costs of Rationality

by RobinHanson 1 min read3rd Mar 200981 comments

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The word "rational" is overloaded with associations, so let me be clear: to me [here], more "rational" means better believing what is true, given one's limited info and analysis resources. 

Rationality certainly can have instrumental advantages.  There are plenty of situations where being more rational helps one achieve a wide range of goals.  In those situtations, "winnners", i.e., those who better achieve their goals, should tend to be more rational.  In such cases, we might even estimate someone's rationality by looking at his or her "residual" belief-mediated success, i.e., after explaining that success via other observable factors.

But note: we humans were designed in many ways not to be rational, because believing the truth often got in the way of achieving goals evolution had for us.  So it is important for everyone who intends to seek truth to clearly understand: rationality has costs, not only in time and effort to achieve it, but also in conflicts with other common goals.

Yes, rationality might help you win that game or argument, get promoted, or win her heart.  Or more rationality for you might hinder those outcomes.  If what you really want is love, respect, beauty, inspiration, meaning, satisfaction, or success, as commonly understood, we just cannot assure you that rationality is your best approach toward those ends.  In fact we often know it is not.

The truth may well be messy, ugly, or dispriting; knowing it make you less popular, loved, or successful.  These are actually pretty likely outcomes in many identifiable situations.  You may think you want to know the truth no matter what, but how sure can you really be of that?  Maybe you just like the heroic image of someone who wants the truth no matter what; or maybe you only really want to know the truth if it is the bright shining glory you hope for. 

Be warned; the truth just is what it is.  If just knowing the truth is not reward enough, perhaps you'd be better off not knowing.  Before you join us in this quixotic quest, ask yourself: do you really want to be generally rational, on all topics?  Or might you be better off limiting your rationality to the usual practical topics where rationality is respected and welcomed?

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