Female Orgasm May Be Tied to 'Rule of Thumb'

Female Orgasm Elusive, Say Scientists

Wallen is testing data that was gathered nearly a century ago by the great-grand niece of Napoleon Bonaparte, who suffered from what was then called "frigidity."

About 75 percent of all women never reach orgasm from intercourse alone.

(PhotoAlto Agency/Getty Images)

Princess Marie Bonaparte, a French psychoanalyst, discovered that the optimal C-V distance is 2.5 centimeters, about an inch, or the space between the fingertip and the thumb.

After collecting data and publishing a report in 1927, her story did not end well. She underwent two experimental surgeries to remedy her own situation, attempting to bring her clitoris closer to her vagina.

She ended up scarred and abandoned finding a physical cure for non-climactic women.

"It was kind of sad," said Wallen. "It's a very interesting metaphoric story. She ended up being a Freudian and totally denied the physical explanation of orgasm. The psychological explanation being if you didn't achieve orgasm it was because you had not grown up."

Despite her travails, he said the data is "highly suggestive, but not demonstrative" that Bonaparte was right.

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"Just as there are physical attributes that would prevent some people from ever becoming a concert violinist, or run the 100 meters in 10 seconds, there are attributes that make it unlikely that some women will ever experience orgasm from intercourse alone," he said.

Though what he coined the "rule of thumb" oversimplifies the biological question, it could be a "boon to women."

Four years ago, Wallen set out to do a well-controlled modern study with the collaboration of Elisabeth Lloyd, a professor of history, philosophical science and biology at the Indiana University.

Lloyd's study of 80 years of previous sex research in her 2005 book, "The Case of the Female Orgasm," debunked theories that there is an evolutionary reason for the female orgasm.

She determined the female orgasm is merely a byproduct of the male orgasm, as both sexes share the same genital nerve tissue in the fetal stage.

"It is perfectly normal not to have orgasms and there were lots of women in evolutionary time who had no orgasms and it had no impact on their fertility," said Lloyd.

Current studies bear this out, according to the researchers: 98 percent of men say they "always" reach orgasm during sex, while women are "evenly distributed" between "always and never."