HARDLY a week goes by, it seems, without a scientific pronouncement on the causes of homosexuality.
For decades, science and medicine pointed toward psychological causes of homosexuality -- distant fathers, smothering mothers, early sexual abuse, etc. But in the past few years, scientists and physicians who have been charmed by the siren song of biology have begun to enter the fray.
While it is certainly laudable that efforts are being made to understand the broad range of factors responsible for complex behaviors like homosexuality, the moral problem with the recent swing toward nature rather than nurture is that those with the keenest interest in homosexuality keep looking to science for their civil rights.
Remember, only a few months ago the nation was agog over the announcement by a California scientist that he had found tiny differences between the brains of 20 men who had died of AIDS and were thus presumed to be homosexuals and a small number of brains obtained from men and women who had expired due to other causes. Many in the gay community expressed relief at the news that science had finally found that the cause of their sexual orientation was in their brains.
Now researchers from Northwestern and Boston universities have published a paper in the Archives of General Psychiatry in which they announce that male homosexuality has its roots in chromosomes, not parenting. This study has some real scientific meat in it. But in its wake have come wildly unsubstantiated value statements about homosexuality.
The researchers studied the reported prevalence of homosexuality in a large number of identical and non-identical twin brothers of self-proclaimed gay men. They also looked at the sexual orientation of adopted brothers of gay men. The results they report are noteworthy. Fifty-two percent of the biologically identical twin brothers said they, like their brothers, were gay. Twenty-two percent of the biologically non-identical twins reported being gay, while only 11 percent of adopted, genetically unrelated brothers of gay men said they were homosexuals.
The rates of homosexuality among biologically related brothers are higher than would otherwise be expected. So, it would appear that heredity plays an important role in causing homosexuality.
OK, so there is a strong biological contribution to homosexuality. Why should anyone care? Well, the authors of the study say that if homosexuality is rooted in heredity, then the case for seeing homosexuality as an illness is weakened. The authors say that ". . . a biological explanation is good news for homosexuals and their advocates." Wrong.
Certainly it is important to encourage and fund studies that examine the causes of sexual orientation and behavior. It is important to understand how we come to be who we are, and understanding the etiology of sexual behavior can provide ideas about what it would take to change.
But biological explanations of homosexuality are not necessarily good news. Suppose science were to find that homosexuality is 100 percent genetic (which no one believes) in origin. Would discrimination against homosexuals end? Would bigots reform their beliefs? No. Those who despise homosexuals would simply advocate the development of prenatal genetic tests so that would-be homosexuals could be nipped in the bud. Homophobes would argue for biological engineering for all homosexuals as soon as possible.
Science provides very little good news or bad news about human nature. It tells us much about how we come to be who we are and what we are up against if we want to be different. But it tells us nothing about whether we should want to change who we are or what way of changing would be best. We have to figure that out for ourselves.
Arthur Caplan, director of the Center for Biomedical Ethics at the University of Minnesota, is a columnist for the St. Paul Pioneer Press.