The VAGGINA hypothesis: Our vaginal, uterine, cervical, clitoral, urinary, rectal, and muscular dimensions of the pelvis, Ourselves.

Two months ago, I did a Twitter Poll.

Link to tweet

When you do polls, Twitter limits the number of choices to 4 and each one has strict character limits. So for example, if I had more room, then I would have written “uterus, vagina, clitoris, bladder, rectum, …”

Because that space in the pelvis is "for" all those four choices (and more), the distribution of answers should have been even, with about 25% of respondents voting for each choice.

However, since the answers were skewed to “birthing baby” that tells me something (exactly what I expected) about what people think of when they think about something’s “primary” reason “for” existence. When asked to choose one, they think that the greater space inside female hips (compared to males') is "for" childbirth.

That birthing and pooping (voiding bowels) were preferred over holding organs tells me that people prefer active reasons “for” something, maybe especially for bone-things, over passive reasons.  

A friend even interpreted “holding” as “holding up” which is not the choice. They action-ated the more passive “holding."

But what about how the sex differences in that space got there in the first place? I'm talking about development (the second choice up there).

If development explains a thing, then suddenly, what it's "for" isn't necessarily anything. It just turned out that way. Maybe sex differences in the pelvis have something to do with sex differences in what's INSIDE the pelvis. Maybe during development and also while these organs are doing their dynamic business throughout life, those bones make room... like how bigger brains develop inside more capacious crania than smaller brains do.

Why look at a woman’s pelvis and think about babies? Why not think about gonads, genitalia, and waste disposal? Maybe you are, but maybe questions about what something is "for" send people's brains straight to evolutionary narratives, which continue to label this space as "obstetric" end of story: Your hips are for babies, ladies, and anyone who tells you otherwise doesn't understand evolution!

In evolutionary circles, we're stuck on childbirth as *the* reason for the patterned sex differences we see in human hips, and we need to get unstuck.

I helped perpetuate that narrow-minded narrative and now I have a paper in press that's trying to help change it.

Until a reviewer of my upcoming paper referred to these ideas as the "spatial packing hypothesis" it didn't occur to me that because I didn't offer a name, people will offer their own dreadful ones!

Meanwhile, a reviewer suggested I stop rattling off "vagina, clitoris, uterus, cervix, ... " and instead refer to them collectively as "reproductive organs" ... completely missing the f-ing point.

It's in that context that I'm conceiving of a better name for this hypothesis to post here, since I missed my chance in my paper. Say it with me...

The VAGGINA hypothesis for sex differences in pelvic dimensions.

VAGGINA =Virile, Active Gonads & Genitalia In Nether Area

It's applicable beyond humans because WOW are there a lot of primates (and beyond) who have sex differences in the dimensions of the pelvis. It's as applicable to bodies with vaginas, uteruses, etc as without, and so one could apply the VAGGINA hypothesis to a study of male pelves. I am not suggesting it is the only explanation for this complex phenomenon (sex differences in pelvic dimensions), but given how we've accepted the power of brains and skulls developing together, I think it deserves some consideration.

That big hole in our hips is rarely "for" babies. It's far more often "for" vaginas and lots of other interesting things!

Even if someone demonstrates that all the organs and tissues normally sequestered to female pelves aren't causing the bones around them to make way, those soft tissues are still present inside the vaginal/uterine/clitoral dimensions of the pelvis far more often than a baby is.

For more about the VAGGINA hypothesis, watch this space and Twitter where I'll announce the paper's publication. Thanks!