= 27d567bc2d48d9f40e9ccc20ea370b15)
Is there evolutionary selection for female orgasms?
>Elisabeth Lloyd: I don’t actually know. I think that it’s at a very problematic intersection of topics. I mean, you’re taking the intersection of human evolution, women, sexuality – once you take that intersection you’re bound to kind of get a disaster. More than that, when evolutionists have looked at this topic, I think that they’ve had quite a few items on their agenda, including telling the story about human origins that bolsters up the family, monogamy, a certain view of female sexuality that’s complimentary to a certain view of male sexuality. And all of those items have been on their agenda and it’s quite visible in their explanations.
>Natasha Mitchell: I guess it’s perplexed people partly, too, because women don’t need an orgasm to become pregnant, and so the question is: well, what’s its purpose? Well, is its purpose to give us pleasure so that we have sex, so that we can become pregnant, according to the classic evolutionary theories?
>Elisabeth Lloyd: The problem is even worse than it appears at first because not only is orgasm not necessary on the female side to become pregnant, there isn’t even any evidence that orgasm makes any difference at all to fertility, or pregnancy rate, or reproductive success. It seems intuitive that a female orgasm would motivate females to engage in intercourse which would naturally lead to more pregnancies or help with bonding or something like that, but the evidence simply doesn’t back that up.
The whole discussion. It backs my theory that using evolution to explain current traits seriously tempts people to make things up.
= 783df68a0f980790206b9ea87794c5b6)
Loading…= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
= f037147d6e6c911a85753b9abdedda8d){kind=logo}
Comments (22)
I was thinking about this yesterday, and came up with a theory I've never heard before that sounds more plausible to me than any of the ones I have heard: Given that penises are designed for suctioning out previous males' semen, female orgasm with 'ejaculation' could be a countermeasure against that, by either putting a barrier between a preferred male's semen and the suction effect of a later male's penis, or by increasing the total volume of liquid containing a preferred male's sperm so that a later male can't suction it all.
(Ew.)
Natasha Mitchell seems to have hit the obvious answer. If women didn't enjoy sex and all mating was reluctant or forced:
And the female orgasm isn't a remarkably complex adaptation, either; the genetic material responsible for the male orgasm was already present and relatively easy to repurpose. (Assuming that the male orgasm came first instead of the reverse, though simultaneous development is more likely than either.)
Do you think that people only have sex because they might have an orgasm? Really?
Modern humans have sex for a variety of reasons, yes. Regardless, individuals who do not enjoy sex are less likely to reproduce than individuals who do. I don't believe this is a controversial idea.
The point is that women generally enjoy sex even without orgasm.
Sure. But those pathways aren't unrelated, and orgasms do contribute to enjoyment. To rephrase the grandparent, individuals who enjoy sex more are more likely to reproduce, all else being equal.
You should read the interview that was linked to; they talked about this very thing. And the guest cited evidence that she claimed supported her, which you should be aware of before arguing against her claim.
This seems close:
http://www.psychologytoday.com/articles/199601/the-orgasm-wars
Except that the link I posted says that orgasm doesn't correlate with conception, and your link just assumes that more sperm uptake will increase the odds. Something's wrong with somebody's theory.
I'm surprised that a highly symmetrical skeleton makes that much difference. It's also surprising to see something echo a weird detail from Doc Smith's science fiction-- in one of the Lensman novels, a doctor goes goshwowoboyoboy over the excellence of a couple of the main characters' skeletons.
You mean this?
"I mean, all these yucky ideas about suck-up and this, that and the other, and that orgasm might be associated with the uterus sucking the sperm through the cervix from the vagina, I think is just a lot of nonsense. And to try and suggest that a behavioural response to intercourse - which may be enormously important for pair-bonding, to keep man and woman together for the rearing of their children - has anything to do with the actual anatomical nuts and bolts of conception is extremely far-fetched."
That seems like unreferenced speculation. The "upsuck hypothesis" has at least been tested experimentally - see the "orgasm-wars" article for the reference.
The article is not just about sperm retention rates:
"Taken together, these findings suggest that female orgasm is less about bonding with nice guys than about careful, subconscious evaluation of their lovers' genetic endowment."
If true (I have no idea what information its based on), this is devastating for evolutionary arguments.
Not really (absence of evidence is poor evidence of absence). Here's a summary of some of the relevant evidence, from last year:
http://www.scientificamerican.com/blog/post.cfm?id=reopening-the-case-of-the-female-or-2009-12-01
The additional uptake of sperm is only 5%. This might make a difference, but it might not be much. I'm guessing that the sperm in the first wave have the best chances, and adding a little more sperm at the back isn't going to do much.
Some more guesses: If it's true that 25% of women are reliably orgasmic, 50% are occasionally orgasmic, and 25% aren't orgasmic, this suggests a single gene, but that would be surprising.
However, it also suggests a mixed strategy. Maybe non-orgasmic women are less inclined to adultery, so their marriages are less likely to get disrupted.
Maybe orgasmic women expect more, so that marriages that satisfy them sexually are better, but marriages that don't are worse.
Maybe occasionally orgasmic and non-orgasmic women are less fond of sex, and therefore better able to bargain for family resources-- which may include resources for their children.
Maybe occasionally orgasmic women try harder to get and keep mates, and keep those mates happy-- intermittent reinforcement.
It's not about the sperm with the best chances to fertilize, it's the sperm with the best offensive and defensive capabilities, relative to another man's sperm. Most spermatozoa are not even capable of fertilizing an egg; they are specialized "blocker" and "killer" units whose main job is to prevent other men's sperm from reaching the egg.
That extra 5% isn't about making a difference to whether she's fertile, but about her ability to choose which man ends up as the father, out of the various men she's having sex with.
Let's say she has sex with two men, one right after the other -- the one that makes her orgasm has a 5% larger army in the trenches, so to speak, which could easily be decisive.
(The book "Sperm Wars" discusses these and other evolutionary pressures on the orgasms, preferences, and genitalia of both sexes, in quite a bit more graphic detail than I think is appropriate for quoting here.)
I think those figures are from Elizabeth Lloyd. They appear to represent figures for penis-caused orgasms.
"In fact, the majority of women reach orgasm through methods other than PVI, usually by direct clitoral stimulation"
25-50-25 doesn't suggest a single gene very strongly. A gene can have any frequency - while practically any combination of genes could easily generate a bell-shaped curve.
It does look like some modest hints in the direction of heritability, but nothing as solid as stats on actual reproductive effect.
How about this one:
"Wealthy men give women more orgasms"
It seems as though the female orgasm still has something to do with selecting an appropriate mate.
If it doesn't pay out in increased chances of reproduction (and that hasn't been proven), then it's not enough for a sound argument.
I haven't seen much evidence supporting the idea that it doesn't pay out.
The evidence for the adaptiveness of female orgasms may be relatively weak - but it seems much better than the evidence for the hypothesis that they are near-neutral - or exist by force of homology.
It's evidence that female orgasm is doing something adaptive (and distinct from what it does in men), even if we don't know what. While it's good to be skeptical of particular ev-psych stories and to acknowledge the cases where we don't yet know the mechanism of causality (e.g. humans' musical sense), the presumption ought to be that complex adaptations rarely arise for no reason.
Part of the hypothesis is that variations which give a significant advantage should be close to universal.
Wow, that's interesting.
Still, it doesn't look like it separates correlation from causation. All sorts of things might cause the partners of rich men to be more likely to have orgasms.