Monday, October 26, 2015

Nothing Up My Sleeve; or, The Silence of the Genes

At first I thought I'd just add to yesterday's post, but decided to start a new one.  After I clicked on Publish and moved on to other matters for the evening, I kept wondering what valid a use a "genetic" test to detect homosexuality could have.  After all, LGBTQ folklore has it that we know from an early age that we're Different, so who needs a test?  I can imagine a confused and frightened young person wanting to take such a test to prove to himself or herself that she isn't gay, and then having to face positive results.  Maybe parents would drag offspring they aren't sure about to the doctor to settle the question one way or the other.  By analogy to similar tests, the only use I can think of for this one would be "diagnostic," and what valid diagnostic use would a test for homosexuality have?

One of the New Scientist articles I linked to yesterday acknowledged some of these concerns.
This concern may be premature. Marc Breedlove at Michigan State University in East Lansing points out that in its current form, the test is not accurate enough to be used to predict whether someone in a new population of individuals is gay with any certainty, since the 67 per cent accuracy of the test is only relevant for the test population, who are themselves not reflective of the general population, in which a much lower proportion of people are gay.

Nevertheless, some researchers contacted by New Scientist raised concerns over the ethical implications of such research. For example, if the test were developed further, could it one day be used to screen for sexuality at an early age?

“Eugenics is always a possibility, but governments that regressive would rarely have enough money to spend on something like this,” says Alice Dreger an ethicist and historian of sexuality. “More likely it would be used by parents.”

Dreger recalls an anecdote from a researcher who studies the fraternal birth order effect. The researcher received a phone call from a man in the US who was looking to hire a surrogate mother – but because of the effect did not want someone who had already had several sons. “That’s not really what I want…” the man had said, “especially if I’m paying for it.”
I wonder about Dreger's remarks.  Once science and commerce have done that voodoo that they do so well, the hypothetical test would soon be affordable, not just for parents (!) but for "governments that regressive."  Regressive governments (like the poverty-stricken Saudi Arabian regime, maybe?) don't have to develop the science themselves, they just need to find a way to pay for it from the aid they receive from the United States.  Even a "centrist" administration will probably go along with selling the test abroad -- finding overseas markets for American products is a bipartisan priority.  Regressive and repressive governments also aren't much concerned with accuracy; a few false positives leading to the execution of non-gay individuals would hardly bother them much.  Where do they find these people?

And yes, of course there are parents who'd be interested in such a test.  Since most antigay bigots reject biological-determinist explanations of homosexuality, one could mock them for using a test based on a biological-determinist explanation of homosexuality.  Bigots are quite comfortable with biological-determinist theories that support their bigotry, and besides, better to be safe than sorry.  In the hypothetical case I outlined above, of parents taking their child to the doctor to be tested for homosexuality, they could still follow up by trying to beat the Gay out of him or her.  I haven't noticed that inconsistency bothers many people.

Dean Hamer, in his New Scientist piece, claimed that "such work won’t worsen homophobia. People who understand the role of biology in sexuality are more likely to be accepting and inclusive." It's a bit odd, really, to find a scientist reassuring the public that there's nothing to worry about because the science doesn't work yet.  The usual line in scientific evangelism is that you can't stop the forward march of Knowledge, and if we can't detect gays with a saliva test today, we'll be able to do so Real Soon Now.

Even forgetting people like Günter Dörner, the German endocrinologist who "classified homosexuality as a 'central nervous pseudohermaphroditism'" resulting from low levels of male hormone in homosexual males, it isn't only "people who understand the role of biology in sexuality" that we have to worry about -- it's the people who don't understand the role of biology in sexuality.  But that group includes a lot of scientists working in the field.

For example, the NBC story that Queerty used as a source for their post included this significant passage:
Dr. Margaret McCarthy, who studies the developing brain at the University of Maryland School of Medicine, said epigenetic changes could happen while a fetus is developing. 

"Developing male fetuses produce very high quantities of testosterone during the second trimester and this directs psychosexual development along masculine lines, a component of which is preference for females as sexual partners," McCarthy said in a statement.

"This study provides a major step forward in our understanding of how the brain can be affected by factors outside of the genome. It is also possible that the experience of being a homosexual or a heterosexual has itself impacted the epigenetic profile. But regardless of when, or even how, these epigenetic changes occur, their findings demonstrate a biological basis to partner preference."
It appears that Dr. McCarthy accepts the popular scientific notion that male homosexuals are in some way feminized, since we have a preference for males as sexual partners, instead of females as "masculine" psychosexual development would produce.  But she's wrong about the effects of hormones, which produce not partner preferences but, at most, roles in sexual behavior: lordotic males who present themselves to be mounted by partners of either sex (or a researcher's finger stroking their backs), female who mount partners of either sex.  They don't explain why a 'normal' male would mount a lordotic male, or a 'normal' female present to a masculinized female.  (This behavior has nothing to do with human homosexuality, but pointing that out would undermine their claims to explain human homosexuality.)  I can't see where McCarthy got the idea that Ngun's "findings demonstrate a biological basis to partner preference," because they demonstrate nothing of the kind.  It's certain that biology provides a "basis" for sexual behavior, as it provides a basis for language and other cultural phenomena; without bodies (biology) these phenomena wouldn't occur.  But the variations in language, culture, and sexuality have not been shown to be determined by biological differences.  But environment and culture also provide a basis for sexual behavior.  The bogus nature/nurture divide is still active in the scientific community.

Many scientists are naive, to put it nicely, about the motives of the people to whom they hand over the new toys they've invented.  Even a low-tech intervention like abortion can be used to bigoted ends, as when it's used to prevent the birth of daughters -- especially when it's combined with higher technology that allows the sex of the embryo to be known during gestation.  It might be acceptable to push for a saliva test that detects homosexuality if it had some positive use, but no one seems to have any idea what that would be, and there are plenty of negative consequences that are all too plausible and likely.

Hamer also brushed aside concerns about a test: "... Ngun’s work does not amount to a sexual orientation test. Even if it can be replicated in more twins with highly correlated methylation patterns, it is unlikely to work in unrelated members of the public."  Why is Hamer so negative?  Doesn't he have faith in scientific progress?  Just because we can't do something now doesn't mean we won't be able to do it later!

So what is the value of Ngun's work, even dismissing all the criticisms of its weaknesses (weaknesses that also characterized the research that made Hamer famous, as it happens)?  Hamer wrote, "My fear is that the furore stirred up will inhibit it. That would be a pity, because sexual orientation is one of the most fundamental and fascinating variations in humanity that we can study."  I disagree with him on both those counts.  I don't think that sexual orientation is particularly fascinating or fundamental, any more than differences in skin color are.  If, as various streams of the LBGT movement have argued, homosexuality is just not a big deal, not a difference that matters to individuals' value or capacity as human beings, then how is it "fundamental"?  One of the points of the Kinsey scale is that homosexuals and homosexuals can be thought of as different in degree, rather than in kind.  Is a Kinsey 2 fundamentally different from a Kinsey 3 or 4?  Where do you draw the line?  For that matter, why is a difference in sexual orientation more fundamental or fascinating than the fact that people are not equally attracted (or attracted at all) to all people of a given sex?  I'm not attracted to all men, and I'm often not attracted to men whom other men desire fiercely.  That looks to me like a more fundamental difference than sexual orientation, but scientists like Hamer don't seem to find it fascinating.  (It's a difference that they either try to overlook, or try to explain by claiming that some people are inherently more attractive, on evolutionary grounds.)

Is a difference in sexual orientation more "fundamental," say, than a difference in language or religion?  Such differences have been taken to be important, to be markers of fundamental human difference worth fighting and killing over, but they are not.  I think it needs to be argued, not postulated, that sexual orientation is fundamental.  Hamer assumes that differences in "sexual orientation" are both fundamental to the individual, and must (therefore?) be based in the genes in some carefully nonspecific way.  Even if he were right about this, decisions of funding need more than his dogmatic assurances, which seem to be motivated by PR aims to justify supporting the work.

Another notorious researcher takes the same tack:
“The scientific benefit to understanding [why people vary in sexual orientation] is obvious to anyone with an iota of curiosity,” says Michael Bailey at Northwestern University in Evanston, Illinois. “The predictive test needs replication on larger samples in order to know how good it is, but in theory it’s quite interesting.”
What I find interesting is that Bailey reads Ngun's study in a way diametrically opposed to Hamer: Hamer dismisses the possibility of a "predictive test," while Bailey sees it as feasible as well as "quite interesting" in theory.  He doesn't seem to have a valid use for it, though. And neither Bailey nor Hamer seems to have noticed the serious flaws in Ngun's study listed by Ed Yong at The Atlantic, which indicates a lack of important analytic skills on both their parts.  Other than that, Bailey can only handwave that it's obvious that understanding variation in sexual orientation has a scientific benefit.  Maybe it has a benefit, maybe not, but that's not obvious.  As Noam Chomsky wrote decades ago about American race-science bearing on intelligence:
A possible correlation between mean IQ and skin color is of no greater scientific interest than a correlation between any two other arbitrarily selected traits, say, mean height and color of eyes. The empirical results, whatever they might be, appear to have little bearing on any issue of scientific significance. In the present state of scientific understanding, there would appear to be little scientific interest in the discovery that one partly heritable trait correlates (or not) with another partly heritable trait. Such questions might be interesting if the results had some bearing, say, on some psychological theory, or on hypotheses about the physiological mechanisms involved, but this is not the case. Therefore the investigation seems of quite limited scientific interest, and the zeal and intensity with which some pursue or welcome it cannot reasonably be attributed to a dispassionate desire to advance science. It would, of course, be foolish to claim, in response, that “society should not be left in ignorance.” Society is happily “in ignorance” of insignificant matters of all sorts. And with the best of will, it is difficult to avoid questioning the good faith of those who deplore the alleged “anti-intellectualism” of the critics of scientifically trivial and socially malicious investigations. On the contrary, the investigator of race and intelligence might do well to explain the intellectual significance of the topic he is studying, and thus enlighten us as to the moral dilemma he perceives. If he perceives none, the conclusion is obvious, with no further discussion.

... The question of heritability of IQ might conceivably have some social importance, say, with regard to educational practice. However, even this seems dubious, and one would like to see an argument. It is, incidentally, surprising to me that so many commentators should find it disturbing that IQ might be heritable, perhaps largely so. Would it also be disturbing to discover that relative height or musical talent or rank in running the hundred-yard dash is in part genetically determined? Why should one have preconceptions one way or another about these questions, and how do the answers to them, whatever they may be, relate either to serious scientific issues (in the present state of our knowledge) or to social practice in a decent society? [from For Reasons of State, Pantheon, 1973, p. 361-362]
Subtitute "sexual orientation" for "intelligence" here, and you have some very good reasons to be skeptical of Hamer's, Bailey's and others' enthusiasm for trying to find a biological basis of sexual orientation.  I can understand why laypeople want to know why we are the way we are, but I see no reason to fund scientific research to understand why people differ from each other.  (Why am I left-handed?  Why am I gay?  Why am I an atheist?  Why am I taller than both my parents and all of my younger brothers?  Why are some people darker-skinned than others?  Why am I attracted to this man, but not to that one?)

Hamer comes closest to offering a scientific rationale for such research: "... I am more intrigued by what the work tells us about the role of epigenetic imprinting – the silencing of genes by methylation. This imprint can pass from parent to child and has implications for a range of complex human traits."  Apparently, though, "epigenetic imprinting -- the silencing of genes by methylation" is relevant to "a range of complex human traits," not just sexual orientation.  There's no particular reason why it should apply to homosexuality (or to heterosexuality), except that traditional forms of biological determinism have failed and We've Got to Do Something.  If I recall correctly, Hamer is one of those gay scientists, like Simon LeVay, who try to justify their research by claiming that it would support gay equality in some obscure fashion.  But gay equality doesn't depend on our being born gay, and finding a role for epigenetic imprinting is not likely to persuade bigots.  What this research mainly shows is that scientists like Hamer don't really understand the role of biology in human behavior and culture -- that is, what it means, socially and ethically and politically, for some trait to be "biological" and "not a choice."

I suspect that Tuck Ngun had never thought about possible social consequences of his work until controversy erupted over his announcement.  If I'm right about that, then his scientific education failed him decisively.  (But then, if bioethicists like Alice Dreger were doing the teaching, it could hardly have done otherwise.)  Judging from the pronouncements of people like Dean Hamer, bioethics in practice largely means finding ways to ward off criticism and get more funding for badly designed research of little or no scientific value.  (Remember that Hamer also wrote a book called The God Gene, arguing for a genetic basis for religion; I don't know who was responsible for that title, but Hamer's in no position to complain that laypeople have inaccurate ideas about genetic determination when he's fostering them himself.)  But then there will always be gay people who will clamor for badly designed research of little or no scientific value that will make them feel less bad about being gay.  Where there's demand, there will be suppliers.