The men-pick-up-the-check norm can also be modeled as an opportunity for men to signal in a costly way. An opportunity to signal may be positive or negative or neutral, depending on the game-theoretic details (as well as side effects further removed from the immediate "game"). Removing the opportunity from one group of people and giving it to another may well increase or decrease the aggregate social welfare and/or cause a transfer from one group to another.
ETA: In case it's not clear, “working out or buying nice clothes” are not perfect signaling substitutes for paying for dinner at an expensive restaurant. Someone with good physique might have good genes, a lot of spare time, or just enjoys exercising. Nice cloths can be reused for other dates and hence can't be used to signal interest in a particular person.
The last thread didn't fare too badly, I think; let's make it a monthly tradition. (Me, I'm more interested in thinking about real-world policies or philosophies, actual and possible, rather than AI design or physics, and I suspect that many fine, non-mind-killed folks reading LW also are - but might be ashamed to admit it!)
Quoth OrphanWilde:
Let's try to stick to those rules - and maybe make some more if sorely needed.
Oh, and I think that the "Personal is Political" stuff like gender relations, etc also belongs here.