The real reason women orgasm revealed – and it’s all to do with ovulation
JUST like the diners in that iconic scene from When Harry Met Sally, scientists have long been baffled by the female orgasm.
The euphoric sensation felt when women reach climax has no apparent biological reason.
It's not necessary for conception and often women don't even experience it during sex itself.
But now experts believe that it may have evolved in early humans to induce ovulation during sexual intercourse.
This is the case for many animals, including rabbits, ferrets, cats and camels, where the female releases an egg while mating.
But it doesn't happen in humans or primates - instead, women ovulate once in a regular monthly cycle.
Mihaela Pavlicev, a researcher at the Boston Children's Hospital, was cataloguing information about the ovarian cycle in different mammals when she noticed a pattern.
She found that the hormones released by animals whose ovulation was induced by mating were the same as the ones released during human orgasm.
Pavlicev, now a professor at the University of Vienna, also noted that the clitoris for these animals was located inside the vagina.
She hypothesised that what humans experience as female orgasm originally evolved to trigger ovulation, and it's a "leftover" trait that no longer has the same purpose.
Put it to the test
To test her theory, Prof Pavlicev treated female rabbits with fluoxetine, a drug known the inhibit orgasm.
She believed that if orgasm is similar to induced ovulation in rabbits, then the drug should in turn suppress their ability to ovulate.
The female rabbits were treated for two weeks, then mated with males, and found to be 30 per cent less likely to ovulate than untreated rabbits.
Describing the results on Monday, Prof Pavlicev said: "We were actually really, really happy that we actually got such a clear result."
The exact mechanism of how orgasm triggers ovulation is unknown, but the authors suggest that as stopping orgasm reduces ovulation, then it must have some role in triggering the release of eggs.
MORE ON SEX
Pavlicev did add however that the researchers don't know how it feels for the rabbit, adding: "We don't know whether they have the same experience as we do."
She added that the difference in the location of the clitoris between mammals with induced ovulation and those that ovulate spontaneously also explains why some women have trouble reaching orgasm through sexual intercourse.
In conclusion, the authors write that orgasm induced ovulation is "a mechanism that still exists in many animals but lost its role in others".
We pay for your stories! Do you have a story for The Sun Online news team? Email us at [email protected] or call 0207 782 4368 . You can WhatsApp us on 07810 791 502. We pay for videos too. Click here to upload yours.