women's orgasms are unnecessary. are men's?

In the comments of another post, Figleaf (whose blog the management cheerfully recommends) has asked one of the most difficult questions I’ve ever been asked – indeed, I’ve been thinking about it for 6 or 7 years and have yet to come up with any kind of answer. He said:

…why assume orgasms are necessary for men either? Red was a hard-core biologist and she pointed out that in numerous species copulation and ejaculation looks a lot more like reflex rather than learned behavior. She said that, especially in open-range prey species like antelopes and gazelles you couldn’t really afford the kind of eye-rolling, toe-curling distraction of orgasms like humans have. But she had a big list of other vertebrates and invertebrates that ejaculate but don’t particularly have orgasms.

She said, and I have to agree, that animals do all sorts of things that are at least as critical to survival as ejaculating without orgasm-like rewards. I think she also pointed out that a lot of animals appear to get as much or more pleasure from scratching itches… and will sometimes go further out of their way, and take considerable risks, to scratch what they can’t reach.


So anyway, I just think it’s really, really critical not only to ask what use orgasms serve in women (which is still a darn good question) but to ask what purpose they serve in men.

My guess is that homology really does play a big role — we really do start out with the same genital buds, and as far as I know there’s nothing specific on the Y chromosome that codes for more than testosterone, with all other sex differentiation resulting from testosterone’s affect on the expression of more universal genes.

A few years ago I even speculated (only slightly seriously) that men’s bigger-than-strictly-necessary orgasms might be due to homologous benefits deriving from completely nonsexual selective pressure based on women’s need to grow some kind of / any kind of padding for the urethra in the birth canal. (My big-headed son damaged my partner’s urethra so badly coming out her bladder nearly ruptured before they could get a catheter through it.)

Anyway, my burning questions are a) why should we assume men need big orgasms either, b) how much of a role does homology really play, and c) can we be certain big orgasms are directly selected for in either men or women?

In a single sentence: is it actually reasonable to assume that men have orgasms to reward ejaculation?

This is such an interesting and complicated comment, I’m actually going to address the three questions in two posts, or else it’ll just get eyeball-numbingly dull for the ladies and gentlemen out there. This one will be about the assumption itself, and the next post will be about alternative ideas.

To begin with, you should all read Elisabeth Lloyd’s brilliant, wonderful, relentlessly precise Case of the Female Orgasm. I adore this book; it is not uncontroversial (how could it be? She spends most of it criticizing other research, which will inevitably result in people defending that work. Incidentally, Baker and Bellis are given delicious justice by Lloyd.) It’s the most interesting and thorough philosophy of science on sexuality that I’ve ever read.

(While I’m on the subject, also read Being There, by Andy Clark; it’s not about sex, but it COULD be – I know because I asked him at a Halloween party once. Long story. Anyway.)

I saw Lisa talk last fall and learned a couple of developments since the book’s publication, but none of those developments included this very difficult question. Really. Very difficult.

Why should we assume men need this absurd, effortful, intense orgasm? I’m not convinced we should, and I’m not convinced that the standard party line about rewarding ejaculation holds water either – if we are going to make an assumption, is that the assumption we should make?

It’s certainly problematic – there’s no evidence I’m aware of that male orgasm is any LESS rewarding in response to masturbation, oral sex, anal sex, sex with fertile v. infertile partners, or, indeed, armpit fucking than an orgasm into a vagina, and only the last can result in conception. So that’s a problem.

Another problem has to do with male sexual development, which would take an entire post to describe, but the short version is that males get trained onto stimuli so that by adolescence they pretty much like what they like. Given that this mechanism is fully functional even through most boys haven’t had vaginal intercourse, doesn’t that suggest a supererogation of orgasm?

A more fundamental problem has to do with what orgasm actually IS, whether or not orgasm is even a “trait.” What EXACTLY is being selected for? One basically assumes it’s the biological structures underpinning the function – or rather the genes representing the biological structures underpinning the function – so what if orgasm is just a byproduct of the biological structures? (See next post for more on this.) A mistake people make when researching the evolutionary function of female orgasm is conflating orgasm with arousal. It’s easy – possibly even easier! – to make the same mistake with men. Arousal uses all the same hardware, so how do we know that selection for those parts = selection for orgasm per se?

Okay. So it’s not a great assumption.

But some assumption – or working hypothesis, anyway – will be made until we can test the question empirically, and I have thought and thought and thought about ways to test it. I have a couple ideas, none of which am I qualified to do myself. My ideas are generally constructed around Tinbergen’s four questions for explaining animal behavior, which are, very very roughly: what does it do (function), where does it come from (phylogeny), how does it work (causation), and how does it change/grow (development).

What does it do? How does having or not having an orgasm change behavior? I think this might be the most difficult to test, because how do you find or create a control group? How do you parse out what arousal and ejaculation do from what orgasm does?

If we’re hypothesizing that orgasm is an ejaculation reward, we need at least three groups in our putative study: men who become aroused, men who have orgasms with ejaculation, and men who have orgasms without ejaculation. If we can get men who have ejaculation without orgasm, that’d be excellent. I don’t think we can get anyone who has orgasm and/or ejaculation without arousal, but I think we can have a useful study without that group.

So first we do some pre-test stuff. We assess their SIS/SES and we get some baseline data about their frequency of sex, desire for sex, all kinds of stuff, including their exposure to sexually explicit media.

We bring these guys into the lab and arouse them to various stimuli – some of them just get aroused, some get aroused and orgasm with ejaculation, and some get aroused and orgasm without ejaculation (<– confound: men who can learn to orgasm without ejaculation may be different in terms of SIS/SES compared to men who can\’t or don\’t.)

And then we bring them back and do it again. (After how long a delay? How many times? Idano!) We assess for changes in arousability and orgasmicity in response to variations on stimuli.

God, the problems inherent in stimuli selection! I don\’t even want to think about it. And we also have to take habituation into account, and perceived v. physiological arousal… Oh my christ this is complicated.

We can maybe see why such a study hasn\’t been done!

Where does it come from? Where evolutionarily, that is. A comparative analysis of male orgasm could be helpful. I heard an excellent paper once that did this for attachment. The theory was that attachment (or rather its biological underpinnings) would correlate with duration (relative to lifespan) and dependency of infancy and childhood. Turns out it did. Someone might do this with male orgasm. If orgasm is about rewarding ejaculation in order to promote conception, what patterns would we expect to see across species? How would orgasm in males be different depending on species-specific characteristics?

Also, someone might also develop a genetic algorithm or other evolutionary theoretical model to see what selection pressure might give rise to male orgasm. I’m a big fan of agent-based modeling (my dissertation was one) and I think this might provide a valuable tool for exploring different hypotheses.

How does it work? This one we have a growing handle on. Basic physiological research gets funded because we need it in order to develop medications, and because there’s reason to believe that the physiology and psychology of sexual functioning and motivation are associated with high risk behavior. However, decoupling orgasm from ejaculation is so difficult in an experimental setting (see What does it do? above), understand orgasm separate from arousal and ejaculation is a BIG problem.

How does it change/grow? Orgasm across the lifespan is a question that’s gotten short shrift, maybe more among men than among women. We know some things about how ejaculation change – “semenarchy” and then the gradual changes in ejaculatory functioning as testosterone decreases over a man’s lifespan – but I don’t know of much work related to orgasm in men as the develop and age.

How might we expect orgasm to change, if it functions as a reward for ejaculation? Well, I hypothesize that we’d see an increase in orgasm reward (however we choose to define that) as sperm quality begins to decline. In parallel to the way that women are hypothesized to have increased sexual motivation in their mid- to early-thirties, to compensate for the decline in their quality of eggs, one might expect orgasm reward to increase even as desire and arousal decrease. That would support the idea of orgasm as motivation in men.

It’s a hard, hard question. The answer doesn’t exist.

Next time I’ll talk about some ideas other than ejaculatory reward for the function of male orgasm.