Setback for Gay Germ theory

http://www.iSteve.com/05JanA.htm#gay.germ

As I've mentioned several times before, the existence of male homosexuality (of the exclusive variety) is perhaps the greatest anomaly troubling Darwin's theory of natural selection, which is otherwise so enormously useful in understanding the living world. Therefore, solving the mystery of the cause(s) of male homosexuality is -- besides all the personal, moral, and political controversy it generates -- of the highest abstract scientific interest. It's as if a few percent of objects in the universe didn't appear to follow Einstein's theory of relativity.

We can be reasonably confident that in contemporary society, homosexual orientation is typically not a choice or a fashion or a product of socialization because it's not terribly hard to predict with more than random accuracy which little boys will grow up to be gay men. Richard Green of UCLA's long tracking study found that effeminate little boys are radically more likely to grow up to be homosexuals than masculine little boys. Similarly, the average difference in thirty retrospective studies asking adult men to discuss their proclivities as little boys found that adult gays were 1.2 standard deviation studies more effeminate than adult straights.

Fundamentalist liberals of the Garance Franke-Ruta ilk are shocked to hear me point out these scientific studies linking boyhood effeminacy to adult homosexuality (a correlation which most people over the age of 35 or so have probably observed among their own circle of acquaintances), but, obviously, these facts about early childhood are the most persuasive response to religious people who consider homosexuality to be a sinful choice of adults. Further, a wider understanding of the correlation between childhood effeminacy and adult gayness can help parents prepare themselves so they won't be so shocked when their sons come out of the closet, thus preventing painful family rifts.

Dean Hamer's gay gene declaration of the cause of male homosexuality proved wildly popular when broached over a decade ago, but little has emerged since to validate it. It's not impossible for male homosexuality to be a genetic trait that is selected for if it had other side effects that increase "Darwinian fitness" (i.e., number of descendents), just as sickle cell anemia is selected for in West Africa because it reduces the deaths from malaria.

It has been theorized by advocates of the gay gene theory for over three decades that homosexuals might have more nephews and nieces and the like, but there seemed to be no empirical evidence for this. I know one researcher who looked for this and found nothing. Then, last year some Italian researchers announced they had found that gay men in Italy could recount more relatives on their mothers' side than their fathers' side, suggesting a connection to the X chromosome. But everyone ignored the obvious methodological concern: gay men famously tend to talk to their mothers more than they talk to their fathers, having more in common with their mothers, so they would be more familiar with the maternal sides of their families.

I first heard of the alternative gay germ theory in the cover story in the Atlantic Monthly of February, 1999 about evolutionary theorists Paul Ewald and Greg Cochran. So, Ms. Franke-Ruta should denounce the Atlantic Monthly, not me.

The gay germ theory has a lot of theoretical advantages. For example, germs can evolve at least as fast as our defenses against them, so an ever-increasing number of medical conditions are found each decade to be caused by infections. In contrast, despite all the enormous interest in discovering genetic diseases, progress has been slow for the predictable reason that natural selection fairly quickly and surely eliminates genes that reduce the number of descendents.

However, theories, no matter how elegant, need to be tested. So, I've proposed a couple of times in the past that somebody check to see if there is a seasonality to the births of homosexuals, as there is with the birthdates of schizophrenics. A seasonal pattern isn't essential to a gay germ theory, but if one existed, it would be evidence for it. If seasonality doesn't exist, it suggest that this theoretical gay germ would not be spread by the same mechanisms as cold and flu germs, which spread more easily in winter with more running noses from the cold and people indoors more.

A reader writes:

I took a look at the General Social Survey which asks people what was the sex of the people they slept with last year (SEXSEX) and their sign (ZODIAC). Looking at the 201 men (SEX=1) who had exclusively male-male sex compared to the almost 6,500 men who had exclusively hetero sex, I couldn't find any differences in the seasons of the two groups' births. Specifically, I looked at various ranges of time within the period between Oct. 23rd and Mar. 20 (Scorpio through Pisces) but found no differences between the two groups in the percentage born during the given period of time. If you're interested, you could fiddle with the numbers at: http://webapp.icpsr.umich.edu/GSS/

UPDATE: Greg Cochran replies:

Come on, Steve, think it through: the only way you'd see a seasonal effect is if there was a key vulnerable period in in early development, probably before birth. A pre-birth infection is possible but not particularly likely: for every infection that hits before birth there must be a hundred that hit later in life.

So, imagine that the mystery bug is something that everybody gets fairly early in life, like RSV. Depending on what month you're born, maybe you get it at 2 or 2.5 or 3. No seasonal effect.

If this involves nuking a hypothalamic nucleus, there probably is no key developmental period.

Steve Sailer's homepage and blog is iSteve.com