Your Penis is Designed to Fight Other Men’s Sperm!
This post is educationally sponsored by: Handbook of the Evolution of Human Sexuality - Female/Female Desire, Sex Culture, Pheromones, and More!
Find out how you can sponsor a post.
According to a study conducted by Gordon G. Gallup from the State University of New York at Albany, a human penis is physically designed via evolution to remove other men’s sperm from deep within a woman’s vagina.
I’ll give you guys and gals a moment to think about all the implications of that theory…
The basic idea is simple. Gallup suggests the reason human male penises have such a pronounced coronal ridge and glans (when compared to the shapes and sizes of other primate penises) is so that during intercourse the penis can “scoop out” the sperm of other men that may still be in the woman’s vagina, thereby giving his own sperm a better chance of being the ones to impregnate the woman.
“The human penis, with a relatively larger glans and more pronounced coronal ridge than is found in many other primates, may function to displace seminal fluid from rival males in the vagina by forcing it back over/under the glans. During intercourse the effect of repeated thrusting would be to draw out and displace foreign semen away from the cervix.” (Gallup et al., 2004, 1)
For those of you who may not be familiar with these particular anatomical terms, here’s a picture of where the glans and the coronal ridge are located.
As you can imagine, the larger the coronal ridge, the easier it is for sperm to get stuck behind/under it and be dragged out of the vagina during intercourse. So, males who have a more pronounced coronal ridge “win” in the genetic evolutionary game.
Up to this point in Gallup’s theory, things intuitively seems to make sense. Why else would penises be shaped the way they are? Until reading this article, I’d honestly never given it much thought, and I assume most people, men especially, have never looked down at their penis during a bathroom break and wondered, “Huh, why in the world are the glans of my penis so much bigger than the shaft?”
If, however, for some very odd reason, a man did ask himself this question, the likely answer would probably be along the lines of, “To make my woman enjoy sex with me that much more!” Right? Bigger glans probably feel better during sex, so men who have bigger glans make women “want” them more and therefore those largely endowed men have more sex than men with small glans and end up with more babies. As a woman, I like this evolutionary explanation better than Gallup’s.
Because when you look a little closer at what Gallup is actually saying, your eyes might just bug out of your head in disbelief, since the real questions becomes “Why would men’s penises have to “scoop out” other men’s sperm from a woman’s vagina in the first place??!!!”
Women Are Incredibly Promiscuous Creatures
At the very core of Gallup’s lovely theory is the notion that women will naturally have sex with multiple men in a very short period of time…Not as an exception, but as a rule!
As we know, evolution is a very slow process so in order for penises to have evolved into a shape specifically meant to combat other men’s sperm means that the “problem” of women having sex with one man after another was serious enough for evolution to do something about it. It’s not as though women of the species went through a sexual revolution or a sexual “fad” during a certain hundred or two years of sleeping around that caused penises to change their shape. Nope. If this was the case evolution wouldn’t have had enough time to deal with this issue.
If Gallup’s theory is correct and penises have really had the necessary time to change shape, it means women have been very very promiscuous pretty much since the beginning of our humanity. And on the flip side, it means men have been more than willing to “share” one woman with his friends. Essentially, just because Tom, Dick, and Harry just did her doesn’t mean Larry won’t give her a shot!
What Do You Think About This Premise?
Feminists - I’m sure the vast majority of women will be very offended and indignant by Gallup’s promiscuous premise. Feminists will no doubt be ready to chop his theory to shreds, saying Gallup is a misogynistic you-know-what who’s using evolutionary “science” to make up wondrous stories that continue to perpetuate the classic myth of women’s sexuality as rampant and dangerous - something that must be controlled in order for civilization to survive.
Swingers - Will use this anti-monogamy evidence to support their cause - claiming the religiously unnatural institution of monogamous marriage is a harmful idea foisted upon us by those in power so the general populous stay in line with what ever current dogma is being preached from on High. Romantic jealousy is learned, and the “natural” state of human sexuality is to give and receive physical pleasure from whomever we so choose when ever the mood strikes.
Men - Will have new reason to suspect their girlfriends and wives of wrongdoing. Finally, there is evidence that proves women are more likely to cheat than are men. Finally, there is a chink in the high-and-mighty sexual armor that so many women carry around like a badge of honor.
Or Are Men to Blame for This Evolutionary Marvel?
On the other hand, what if women aren’t to blame at all? What if this odd adaptation is due to men continually raping women? Rather than women voluntarily having sex with multiple men consecutively, what if it was forced? Maybe women aren’t promiscuous at all - but men are sexually uncontrollable! So uncontrollable that penises have literally become genetic weapons against each other!
Tom, Dick, and Harry already raped her, so Larry’s penis has become capable of removing their genetic material and replacing it with his own. How convenient! Once again men are the perpetrators and women are the victims.
In fact, there’s evidence to suggest exactly this:
“…Goetz and Shackelford (in press) have uncovered preliminary evidence that a substantial proportion of wife rapes involve husbands who suspect their wives had been unfaithful…” (Gallup et al., 2004, 21)
In other words, when men find out or suspect their wives have cheated on them and had sex with another man, they rape her. Hmm. Good to know. Now there’s an idea feminists can grab a hold of and run with for years…
Then Again, Maybe This Penis-Shape Theory is Complete Crap
Of course, all of the above thoughts assume that Gallup is correct to believe penises are shaped the way they are in order to get rid of other men’s sperm before depositing their own. But Gallup could be completely wrong.
Speak Sexy’s Alternate Penis-Shape Theory
Like I said, I like my own theory better. I’m going to keep believing male penis glans are bigger than the shaft for the sole purpose of pleasing the women they have sex with. No promiscuity blaming. No awful rape scenarios. Just good ol’ sexual enjoyment is at the heart of Speak Sexy’s Penis-Shape Theory.
To recap - The bigger the man’s penis glans, the better sex feels for the women he sleeps with, the more women want to have sex him, and the more children he sires because of it. Viola.
I think my theory works out well for everyone. Penises are not ultimate-fighting-machines against other men’s sperm (leave it to a man to come up with that theory!) They are pleasure devices made solely for women’s enjoyment (and leave it to a woman to come up with this one!).
What do YOU think? Which theory will you believe? I’d really love to know!!
Here Are Some Links About Gallup and This Theory:
- Reference Article: Gallup, et. al. “Semen Displacement as a Sperm Competition Strategy in Humans.” Evolutionary Psychology. Vol 2 - 2004. p 12-23.
- BBC News Write-up About Gallup’s Theory
- About Gallup’s Work - (Mostly About Semen - Really Fun Stuff)
You May Be Interested In:
- The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature
- The Evolution of Desire: Strategies of Human Mating
- A Natural History of Rape: Biological Bases of Sexual Coercion
- Handbook of the Evolution of Human Sexuality
- Evolution, Gender, and Rape
If You Enjoyed This, Then Don‘t Miss:
- Tricky, Tricky Cowper’s Gland!
- With Penis in Hand
- How to Use Your Penis; Techniques for Large and Small
Pssst Sexy, I know you're new here. Like the girls? Like the vids? Want some kinky advice or toys to play with? Stick around or subscribe if you like. I'm looking forward to getting to know you - intimately. See you around gorgeous. ;)
speaksexy @ November 18, 2007

















I like your theory better! And I loved the “what would they think” portion…but in a way I guess the theory presented originally makes some sense–but as to whether it is to show that women are naturally promiscuous, or because men regularly rape women…well, I think I’d prefer the former to the latter on that one, but I’m sort of an optimist.
Rae - Welcome to S.S.! Thanks for stopping by.
I’m going to be an optimist too when it comes to the original theory - because the rape alternative is much too scary to consider.
I guess that’s 1 - 0 for my theory so far. Woo-hoo!