Phrenology is pseudo-scientific (a.k.a. baloney) theory which claims to be able to determine personality traits based on skull shape.
Kim Wallen, professor of psychology and behavioral neuroendocrinology at Emory University has proposed the idea that the clitoral-vaginal distance can be a physiological indication of a woman’s ability to experience a vaginal orgasm.
In fact, there’s even an easy “rule of thumb,” Wallen says: Clitoris-vagina distances less than 2.5 cm — that’s roughly from the tip of your thumb to your first knuckle — tend to yield reliable orgasms during sex. More than a thumb’s length? Regular intercourse alone typically might not do the trick.
Princess Marie Bonaparte, a psychoanalyst, studied this phenomena in the 1920’s, and gathered c-v and orgasm data.
Recently, Wallen dug up Bonaparte’s measurements and analyzed them with modern statistical techniques. Sure enough, he found a striking correlation. Now he is hoping to do his own measurement study.
As of now it remains plausible, but uncertain. We will withhold judgment until a modern scientific study is done. Some data has been gathered to indicate how widespread the problem may be.
Preliminary work has revealed that only about 7% of women always have orgasms with sex alone, he says, while 27% say they never do.
Dr. Wallen also preaches positivity:
“Personally, I don’t think the inability to experience no-hands, penis-only intercourse with orgasm says anything about a happy sex life,” he says. “Maybe it could allow couples to be a bit more inventive in how they have sex.”
Dr. Wallen is the author of Reproduction in Context: Social and Environmental Influences on Reproduction, which examines reproductive behaviors in animals ranging from turtles and lizards to humans and nonhuman primates from the perspectives of ethology, endocrinology, behavioral genetics, and evolutionary ecology.