It occurred to me that since Erfworld has no children, attraction serves little purpose other than fun, until I was reading through the archives and went back over the bit about 'Natural Thinkamancy' and the statement that there are spells which can influence the unknown value of loyalty. Wheels starting turning in my head.
One could argue that attraction, and not just the sexual kind, but specifically how much one much person's ability to influence the actions of another, could qualify as a natural form of the type of magic that governs loyalty spells (assuming that there is such a branch of magic, if it isn't Thinkamancy). Or in other words, the function of attraction in Erfworld is to directly influence the unknown loyalty statistic.
An extreme example of this kind of magic could be Ansom's current obsession with Wanda. There is definitely magic involved to make one person attracted and completely loyal to another, and therefore Wanda completely controls Ansom's actions. A lighter, natural version, would be Parson's humane treatment of Bogroll. That's where things get iffy. Where do we draw the line between magic and normal social interaction? Between statistic and life? Is there such a boundary in Erfworld?
However, like Thinkamancy, it could be very subtle. A person could be inclined to do one thing or another, but certain actions bring one inclination to the forefront. Wanda throwing her robe on Stanley's desk made him more inclined not to disband Parson. At the other end of the spectrum (one person becoming less attracted to another) Parson talking smack to Ansom made him more inclined to going into a self-righteous rage (natural Shockamancy?), which made his own troops slightly less loyal to him. The loyalty statistic represents the bond between two units, attraction (magical or otherwise) is only what is represented by this statistic. Since it is unknown, there doesn't seem to be a clear distinction between normal social interaction and natural magic. Its a matter of perspective I suppose.
To speculate a bit further, one could argue that the loyalty between two units also represents the strength of a magical bond between the two. For example, the powerful bond between Jillian and Wanda when it was broken, reduced Wanda to a catatonic state for a while. Heartbreak or magically induced paralysis? The implied bond between Maggie and Sizemore aided in the reconstruction of Gobwin Knob. One could then further speculate that as attraction solidifies into love it strengthens this bond accordingly, which in turn influences all kinds of spellcasting where more than one person is invloved. Love could very well be the most powerful force on Erf.
I'm inclined to think that this kind of magic falls under the category of Date-amancy, just because the name seems to fit a school of magic concerned about what makes people attracted to one another. It's very possible that this is just a subset of Thinkamancy. It would be hilarious if any of the Naughtymancies still had an open spot.