Academic paper of the week: The social norm of leaving the toilet seat down: A game theoretic analysis.

Yes, it's as good as it sounds. Here's the abstract:

We model the toilet seat problem as a 2 player non-cooperative game. We find that the social norm of leaving the toilet seat down is inefficient. However, to the dismay of “mankind”, we also find that the social norm of leaving the seat down after use is a trembling-hand perfect equilibrium. Hence, sadly, this norm is not likely to go away.

(via The Bayesian Heresy)