Everyone knows why women fake orgasms; now researchers at Yale have come up with a theory about why women have orgasms in the first place. A Yale news release reports that, because orgasms play no obvious role in human reproduction, the research focused on a specific physiological trait that accompanies human female orgasm — the neuro-endocrine discharge of prolactin and oxytocin. When the scientists looked for this in other mammals they found that in many mammals this reflex does play a role in ovulation. So, they theorize, female orgasm may have evolved as an adaptation for a direct reproductive role — the reflex that long ago induced ovulation. They note that “This reflex became superfluous for reproduction later in evolution, freeing female orgasm for secondary roles,” like pleasure for instance. Wait, there’s more: a comparative study of female genitalia revealed that, coincidental with the evolution of spontaneous ovulation, the clitoris was relocated from its ancestral position inside the copulatory canal. This modification made it less likely that the clitoris receives adequate stimulation during intercourse to lead to the neuro-endocrine reflex known in humans as orgasm. The researchers note that “Such evolutionary changes are known to produce new functions, as is well established for feathers, hair, or swim bladders, etc., which originated for one purpose and were coopted into secondary functions later.” So, sure, orgasms are like feathers. But not exactly.