Adventures in Ethics and Science

Following up from yesterday’s post about how knowledge about the biological basis for X doesn’t tell us whether X is to be valued or pathologized, I need to put a few more points (including some questions) on the table.

First, in the comments thread to the Feministing post that prompted my post, a common (and frustrating) misunderstanding of claims from evolutionary biology has reared its head:

I wouldn’t put the clitoris in the same catagory as the male nipple by any means. The clitoris is not a by-product, and by the way neither is sex. And “liking sex that does not result in reproduction” could be applied to heterosexuality as well. …

Why do most of you not assume that homosexuality is a product of evolution? A direct product (not a by-product) of being human? If it wasn’t a desirable trait in some way then it would have been eliminated through natural selection.


The position of the commenter seems to be full-on adaptationist: every heritable trait that’s in our gene pool is there because it was selected for (because it confered an advantage in terms of living long enough to pass on our genes) at some point in our evolutionary history. While some evolutionary biologists are (or have been) adaptationists, not all are.

I don’t know that there’s a necessary link between being an adaptationist and taking umbrage when some trait you really value is labeled an “evolutionary byproduct”. But there have been some fairly explosive reactions to claims that physiological phenomena like female orgasm are evolutionary byproducts — that they are not selected for. I’ve blogged about this before, as have others, but let’s get the goods from a biologist. This is PZ Myers writing about Elisabeth Lloyd’s book about attempts to give good evolutionary explanations for the female orgasm:

Right at the beginning, she lays out the prerequisites for demonstrating that a feature is an adaptation. It has to be shown to be the product of genetic variation, it must be shown to influence reproductive success, it needs to have a mechanism shown to work in nature, and it should be shown by experimental manipulation of the trait or environment to have an effect on reproduction (the last one can’t be done in humans, obviously). This is not controversial; these are the basics. Then through the middle of the book she goes through each published hypothesis for the origin of the female orgasm and assesses it against each of those criteria, and also examines each for internal consistency and conflicts with the physical evidence. This is all just plain good science.

Lloyd settles on Symon’s explanation, that female orgasm is a developmental byproduct of selection for male orgasm, as the best supported explanation. That word, “byproduct”, seems to be what is arousing most of the critics’ ire, with the implication that unless something is intrinsically advantageous to reproduction, it is less valuable. This is not about value judgements, however; Lloyd is not arguing that the virtue of orgasms lies in their ability to promote pregnancy in women (although that is exactly the idea the adaptive hypotheses for it are promoting)–she’s demonstrating that many androcentric assumptions about female orgasm, such as that it promotes pair-bonding with the male, or assists sperm to enter the reproductive tract, or encourages women to lie about in a puddle of semen, are just not credible or supported by any good evidence. She suggests that maybe she should change the label from “byproduct” to “fantastic bonus” to get around this naturalistic bias, but I don’t know that I agree. I suspect that a great many human features we like are byproducts (OK, “fantastic bonuses”), and people need to get used to that fact. That a specific feature has been the target of selection does not necessarily mean it is “better” in social terms.

(Bold emphasis added.)

Let’s say it together: Being a target of selection doesn’t make a feature something we should value; being an “evolutionary byproduct” doesn’t mean we shouldn’t value a feature. Biology gives us all kinds of neat knowledge about where things come from and how systems function, but it’s up to us to decide what we value. This means biological knowledge shouldn’t be blamed for our decisions about what to value, and it also means that biology can’t make life simple for us by telling us what to value. The heavy lifting here is on us.

Razib has an interesting post in which he ponders how genetic screenings might (or might not) play a role in parents’ individual choices. I find myself pretty torn about these issues. On the one hand, parents (and parents-to-be) are the ones who are actually going to have to raise the kids, and their judgments about what kind of challenges they are up to are important. On the other hand, their kids will be swimming in a gene pool made up of other kids whose parents who have made their individual choices — and certain choices that are good for an individual within the population may, if enough other people exercise the same decision, end up being bad for the population as a whole, and even for the next generation of individuals within that population.

Imagine, for example, a country that limits families to one child and that has a tradition of valuing sons much more than daughters. In such a country, it would not be surprising if parents used prenatal screening as a way to detect and selectively abort female fetuses. This could even represent a caring choice on the part of the parents — they wouldn’t want a daughter to have to suffer through the hell it is to be a woman in that society. But what happens when all the sons have grown up and start looking for wives? Oops.

Personally, I also worry about unforeseen consequences of our choices down the road. Perhaps I only want children with attached earlobes (because I find detached earlobes aesthetically displeasing) and use prenatal screening to achieve that goal. Maybe my beautiful attached-earlobe offspring start a trend in my region and soon all the other parents are ensuring that they only give birth to attached-earlobe progeny. This couldn’t possibly do any harm to the gene pool, could it?

Who knows? Maybe there are other important genes close to the earlobe allele, and possibly we end up with less variation in those genes which could eventually come back to bite us.

I should note as well that Ben at The World’s Fair has noted that the earlier discussion here was pretty disconnected from the history of scientific values and the history of attitudes toward sexuality. He links an interview he did with a historian and philosopher of sexuality, so hie yourself that way to get some historical context.

Finally, we come back to the big philosophical questions: Is more knowledge always better than less? And does knowledge impel acceptance or action?

I value knowledge, but not about everything. Case in point: I purposely avoided getting any knowledge about the sex of either of my offspring before they were born. Not only did it not seem especially relevant (OshKosh overalls and Onesies do the job no matter what the sex of your kid), but it seemed like it would give the illusion of predictability — like it would somehow tell us at least a smidgen about what we could expect from the child. I would rather not labor under such false impressions.

Of course, it’s nothing about our scientific knowledge that tells parents that girl babies are like this and boy babies are like that — it’s cultural assumptions that people are leaning on. But we live in a culture, so it’s hard not to do that. Separating what the science tells us from what we were inclined to believe beforehand is pretty difficult. (Also, most scientists go home at night to the culture the rest of us are living in.)

And that makes the non-scientist’s reaction to scientific knowledge about the biological basis for X interestingly different in different cases. While people engaged in the struggle for equal treatment hope that finding a biological basis for homosexuality will establish that it is natural, not a choice, and thus deserving of respect, others who see homosexuality as a problem may see research into the biology of homosexuality as the first step in finding a “cure”. The science seems like it could be used to support either of these goals. Similarly, research into (in utero) biological factors that might explain why more boys than girls score really high on mathematical aptitude tests could (but for some reason hardly ever does) prompt a movement to create prenatal conditions more conducive to producing female math geniuses, or it could (as it does more often) prompt people to decide it’s natural for boys to be better at math than girls. (Interestingly, all the environmental influences between birth and age 12, when the tests are taken, magically drop out of the discussion, but that’s another rant for another day.)

Maybe the real difficulty here is that biological systems (like human beings) are really complex, so any given finding is only going to give us a tiny piece of the puzzle. And, we already have some fairly strong opinions about human beings (having lived our whole lives as human beings). So it’s pretty hard to prevent an isolated scientific result about human traits and not bring all our cultural baggage into how we interpret it. We just have to remember that we, not the scientists (usually), are the ones schlepping in that baggage.

Comments

  1. #1 razib
    June 28, 2006

    The position of the commenter seems to be full-on adaptationist: every heritable trait that’s in our gene pool is there because it was selected for (because it confered an advantage in terms of living long enough to pass on our genes) at some point in our evolutionary history. While some evolutionary biologists are (or have been) adaptationists, not all are.

    two points:

    1) ironically, heritable traits, those which exhibit populational variation, are almost subject to ambivalent or weak selective forces. otherwies, there wouldn’t be populational variation on said trait.

    2) the naive adaptationism that you point to, and allude to, becomes rarer the close you get (in exp.) to genuine evolutionary biologists (as opposed to those who appeal to evolutionary reasoning outside of biology).

    3) you point about the dimishment of variation through choice is an interesting one…it presupposes uniformity in preference. there are complex biological questions here, but, i over the long evolutionary run there would likely be some frequency dependence here. e.g., wild sex imbalances would probably change incentives.

  2. #2 razib
    June 28, 2006

    btw, attached earlobes are recessive i believe. so it is possible that some parents simply couldn’t produce such children (you need at least one copy of the allele in both parents).

  3. #3 Mouth of the Yellow River
    June 28, 2006

    Imagine, for example, a country that limits families to one child and that has a tradition of valuing sons much more than daughters. In such a country, it would not be surprising if parents used prenatal screening as a way to detect and selectively abort female fetuses. This could even represent a caring choice on the part of the parents — they wouldn’t want a daughter to have to suffer through the hell it is to be a woman in that society. But what happens when all the sons have grown up and start looking for wives? Oops.

    Ni hao! Kannichi Wa!

    It is not only surprising, but has resulted in a critical 120 to 100 imbalance in my old homeland.

    But it is for selfish rather than altruistic reasons. Boys then and now are the ones capable of taking care of aging parents.

    And regarding topic regarding the number of preceding males theory on determination of X characteristics, the result would predict that homosexuality would be very low in China since all males are the eldest males after multiple aborted pregnancies.

    MOTYR

  4. #4 SteveG
    June 28, 2006

    I’ve never understood the appeal of ethical naturalism. Hobbes did a pretty good job explaining that nature is a really scary place and ethics come into play when we realize that we can set up a happier place to all be together. My guess is that the motovation behind the view is tied in to a version of free market libertarianism — if we are going to be social Darwinists these days, we better be biological about it and equivocate between “selected for” and “is morally desirable.”

  5. #5 ck
    June 28, 2006

    Thanks for this, and the links. I have to do some more thinking–and finish the Foucault I’ve been trying to work through. But intially, I’m apt to blame my analytic philosophy training for the way I’m approaching these questions. Ahistorical–isn’t that a compliment?

    In response to what you say, though–
    Being a target of selection doesn’t make a feature something we should value; being an “evolutionary byproduct” doesn’t mean we shouldn’t value a feature.

    This is of course, presuming that one is not debating with a creationi–oops, I mean, intelligent design proponent. The discussion is a non-starter in that instance. Nature does provide a normative blueprint, on that understanding (except that sin can be brought in as an ad hoc explanation for ‘disease’).

    Too, your comment about unforseen consequences is interesting. Even if we could know all the consequences of selecting for an attached earlobe allele, we’d still have to evaluate whether the consequences are good or bad. And then we’re back to where we started from.

  6. #6 David Harmon
    June 28, 2006

    There’s also the point that something which doesn’t seem terribly useful “now” might be *very* useful in other contexts. Consider how color-blind people get proportionately better detail vision, and carriers for sickle-cell anemia (et al.) have better resistance to malaria.

  7. #7 MD
    December 2, 2006

    I tend to take the view that evolution seems “smarter than we are…”. It seems rather obvious to me (am I missing something?) that the female orgasm is a case of “appropriate technology”. Women with a propensity for enjoying orgasm too much, would probably never put enough time into child-rearing, which can be a negative evolutionary trait. Women without a propensity for orgasms wouldn’t have enough children. Like always, nature strikes a happy (variable) medium.

    Add to that that in evolutionary terms, the traditional role of women has not given them a great deal of choice in avoiding reproductive activity, if the male wants it… So, orgasmically challenged women would not fail to reproduce, further diluting the orgasm trait. Of course, this is based on traditional roles of the hunter-gatherer society, etc. etc. The liberating effect of modern technology/economy changes everything.

    My thoughts on sex selection and it’s resulting social consequences –
    (a) when you give someone the power -i.e. abortion on demand, which I’m all for – you have to accept that people may not use the power to live up to your ideals – whether that’s a married couple who decide “I’d rather pay off the house, car, and have that European vacation first” or the (usually foreign) couple who decide boys ar “better”.
    (b)the countries which produce demographic consequences are learning a valuable lesson. Perhaps a generation of sex selection will produce a next generation which will see the value of both sexes. If they’re stupid (men are…) it will take two generations. But then, India will probably be charging doweries the other way, as in Africa – pay the bride’s parents. I hope too, it leads to a social situation where the scarce sex holds the upper hand…

    I don’t think it’s that easy to determine the full cause and value of any trait; “good” or “bad” is a subjective thing. Regarding homosexuality, I do think that it’s a “difference”. I hope that’s a sufficiently neutral word (are any?). I tend to think that any trait that tries to remove 1% to 5% of the population from the breeding pool (depending on whose numbers you believe) cannot be directly genetically induced. I tend to favour the view that it’s a side-effect (occasional trait) of something much more useful evolution-wise; the sickle-cell anemia analogy comes to mind.

    There are deaf people who think that their lifestyle is something precious and don’t want their children “cured” with ear implant technology. People who aren’t deaf can’t imagine valuing deafness as “good”. I know my need for glasses – while not something I would scourge any humans for – falls in the category of traits I would consider NOT passing on if I could choose.

    All knowledge can do is give us choices. Some will choose wisely, some won’t. The possibility of bad choices should not stop us from seeking knowledge.