If you're looking for a sure thing, try this. In any discussion of modesty, someone will drag out the old argument: women should dress appropriately—however "appropriately" is defined in the particular community—so that men will not be tempted to view them sexually. The idea shows up in different forms, falling anywhere on a spectrum from sensible advice to outrageous provocation, but show up it will. And just as reliable, in my circle anyway, is the vigorous protest that will follow from feminist-minded interlocutors: men are responsible for their own lustful thoughts, and the problem, if there is one, is theirs to fix.

The disagreement is so bitterly entrenched that it's easy to overlook the common ground that both positions share. Both sides recognize the tremendous pressure trained on the young female body, that perpetual object of male sexual desire and female social desire, and both sides generally agree that this pressure can harm the young women who inhabit those bodies. They part ways on the question of how to best alleviate the pressure, with one side putting the onus on women's sexual behavior, in particular on the visual display of their bodies, and the other side putting the burden on men's sexual behavior, or on the visual consumption of the female body. But it's helpful to remember that the two sides share some important common ground in the beginning.

I favor the feminist approach on the basis of some rather hazy notions of dignity and personhood, but for a moment I want to put those notions aside and focus only on the question of utility. Which approach actually works better? And works better to accomplish what? To answer that question, we should begin by defining the purpose of modesty norms, which can be a surprisingly tricky task. Here's one way of thinking about the problem.

In any sexual marketplace—picture a frat party, or the drawing room at Downton Abbey—men and women exchange signals of desire and availability, or try to, usually in the midst of a noisy social scene with messages shooting in all different directions. Pairing off happens most efficiently—that is, with a minimum of confusion and to everybody's mutual satisfaction—when signals of availability are targeted closely to the objects of desire: you send a signal to the right person, and he or she responds one way or the other, and you're off to the races or back to the drawing board. The trouble with provocative dress, in public anyway, is that it broadcasts the signal; unlike flirting or gift-giving, say, which can be directed at a single person, the visual image of a body—and the sexual signal it sends—is available to everybody within real or virtual eyeshot. So one way of thinking about modesty is as a means of directing sexual signals more efficiently.

If you'll tolerate the technical metaphor for just a bit longer, we can try to intercept the inefficient signals sent by provocative clothing either at the point of transmission or the point of reception; that is, we can try to get women not to broadcast availability or desire through their clothing choices, or we can try to get men not to interpret clothing choice as a sexual signal at all. Which effort is most likely to succeed? It's hard to know what kind of evidence one could offer to settle the question, and any answer is going to be a bit speculative, of course. But I would suggest that it's easier to change women's sexual behavior than men's, and thus the former effort is likely to be more successful.