Females, by and large, simply do not see males who don't treat them as inferiors as sexual beings.
Begin with a female with whom you have had one of those irritating "we're just friends" relationships since day one - complete with frustrating long LONG hugs, constant stories about the last guy that shit on them, complaints of "why can't I find a man like YOU?" in spite of the fact that she smilingly shuts down any passes YOU actually make, et cetera, et cetera, ad infinitum. For preference, pick one whose shit you have gotten thoroughly sick of already, to the point that it's gotten really hard to bite back savagely caustic remarks.
Quit biting it back - when you feel the caustic remark coming on that's just too mean to say, LET IT OUT. Bring teh funnay - and not in a nice way. Treat her with amused, tolerant contempt. Important note: NO BITTERNESS ALLOWED - you're being contemptuous, not spurned. Continue to pay her attention, but don't hesitate to bag on her hardcore, and show no sign that her opinions or feelings really matter much.
Continue for approximately six weeks.
Evaluate the results of your experiment. Is the subject more attracted to you, less attracted to you, or about the same? Formulate your conclusions - if they validate your hypothesis, you now have a theory.
hotcrab: have you put this in to practice?
jimbojones: let's just say it's definitely a theory, not just a hypothesis
jimbojones: there was this chick Lorie that I was friends-with-mad-chemistry with for years that eventually I got so tired of her shit that I did that as a conscious experiment
jimbojones: but by then even when she'd start getting interested I knew her too well to really want it
jimbojones: it was funny, she was like a fucking Pavlov dog
jimbojones: I actually performed that experiment on her like three separate times
jimbojones: you could practically GRAPH her changing sexual interest levels
Important Note Concerning The Asshole Theory:
Any given female, upon hearing of the Asshole Theory or any experiment used to test it, may or may not agree that it would work on most women in general. She WILL, however, promptly and unbiddenly declare "that would never work on me." This declaration has absolutely no bearing on whether she is, in fact, one of those women who would not respond to the experiment - it simply demonstrates that she is female.
This is such a reliable response that you could probably sex kittens this way - just listen for the outraged "miaou!"
Addendum for Ladder Theorists:
Think of the Asshole Experiment as an experimental alternate method of ladder-jumping.