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If you thought studying booty calls was a nice way to earn a living (or, at the very least, a Ph.D.), how about this: counting strippers' tips. Psychologists at the University of New Mexico recently found that strippers made an average of $70 in tips on days when they were most fertile, $35 during their periods, and $50 the rest of the month. Private dancers on the Pill, on the other hand, averaged $37 no matter the time of the month.

Psychology Today helpfully notes, "The contraceptive produces hormonal cues indicating early pregnancy, not an enticing target for a would-be suitor." The lead researcher attributes the tip fluctuations to changes in body odor, waist-to-hip ratio, facial features, and perhaps unconscious changes in a woman's behavior. Who knew the guys at strip clubs were so picky?! The implications for strippers are clear: stay home during your period, just like the Bible tells you to! But how about for the rest of us? Um, we guess if Aunt Flow is in town, then dinner's on you? And in the meantime, keep an eye out for our forthcoming international best-selling dating advice book, He's Just Not That Into Your Birth Control. [via Gawker]