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Nov. 11th, 2010 06:12 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
Dan Savage has spent an awful lot of time talking about Sex at Dawn, a new book that he thinks justifies everything he's ever said about monogamy, unnaturalness thereof. Reading between the lines of his praise, and the fact that less invested readers characterized it as page after page of "I bet you don't know about.... BONOBOS", I got the distinct impression that this book would have many anecdotes I would find interesting but fail at science, and I'm really tired of reading bad evopsych: not because I don't think evolutionary psychology is trash, but because I've seen how incredibly valuable it can be done well, and seeing it abused hurts me the way watching a movie adaptation of his work hurts Alan Moore. But then one of the authors, Christopher Ryan, was on the Savage Love podcast, I was on the bus, and I was bored with my book on tape, so I ended up hearing part of it anyway. And wow, reality was worse than I could imagine.
The first puzzle he tried to explain was twofold: 1. why is the head of the human penis larger than the shaft? 2. why does human intercourse last so long, and involve thrusting, when most animals enter, ejaculate, and exit in a matter of seconds? These are perfectly reasonable questions to ask. But his answer...I need to give it its own paragraph so its stupid doesn't infect the others.
"Humans have large penis heads and thrust during sex to create vacuum pressure that will remove sperm left in the woman from previous sex with another man"
I want to say I can't count the things that are wrong with that statement, but I'm always up for a challenge, so lets try
1. After some fairly short amount of time (I want to say a few hours, but I could be wrong), any sperm that hasn't made its way into the uterus is clearly never going to reach the egg. But I suppose it's possible guard sperm (whose existence is controversial) are sophisticated enough to stick around near the cervix.
2. Semen removal during sex is actually pretty common. We know what it looks like. It looks like those sharks that store seawater in their pensis and inject into the female shark's reproductive tract (which is not the vagina and I'm pretty sure involves sperm storage, but I can't remember the term), or those ducks with barbed penises that physically scrape the semen out, damaging the female duck in the process. Or it looks like drosophilla, which injects some really *nasty* chemicals into the female that, which in the absence of countermeasures, kill the female. All of these are easy to directly observe. Compared to them, "we have this slight deviation from a perfect cylinder", with no experimental evidence to back his claim, represents the worst of evolutionary Just So stories.
3. Speaking of which, I don't see how he can address this without mentioning humans have fantastically boring penises, and this is usually cited as evidence for at least short term monogamy. Seriously, we think a basic cylinder with some detailing is normal 'cause it's what we see, but if you look at other animals, even other mammals, you get the sense that human penises are something Great Penis Designer knocked off while he was waiting for his really fantastic mushrooms to kick in.
4. Nor is the claim that only humans thrust particularly well backed up. As counter-evidence, I present the results of youtube searches for <http://www.youtube.com/watch?v=6r5queuvkq4>"turtle sex" and "chimp masturbates with frog". Now, it's possible we go longer than other animals, but nothing he's said would explain that, even if we assume its true.
5. And of course, there's the fact that thrusting involves going in as well as out, and it seems like that might hinder the sperm removal process. In fact, the only time it could possibly remove sperm is when the penis is comes out for the final time, immediately after ejaculation. This seems like the worst possible time to develop plunger dick.
Ryan went on to say many, many stupid things, but in theory he could support them better in the book, so I'm not going to comment on the unbelievably stupid idea that men get tired after sex and women don't *because* other men are waiting for their turn. I think I am going to brave the book though: it's been a while since I had a good Angry.