Pathogenic hypothesis of homosexuality

From Wikipedia, the free encyclopedia

The Pathogenic hypothesis of homosexuality, or the gay germ hypothesis, argues that a pathogenic cause of homosexuality is pointed to by the supposedly reduced number of offspring produced by homosexuality, meaning evolution would strongly select against it, by the low identical twin concordance for homosexuality, which further argues against genetic influence, and by analogue with diseases that alter brain structure and behavior, such as narcolepsy, which are suspected of being triggered by viral infection. It is inaccurate to refer to this hypothesis as a theory, as a theory represents a well-tested and verified hypothesis that has withstood all currently possibly scientific scrutiny and inquiry. At present, it is a speculative hypothesis.

Gregory Cochran, who has generated attention for his ideas in evolutionary medicine and genetic anthropology, and Paul Ewald, professor of biology at Amherst College, have advocated a number of pathogenic theories of disease, and conclude that this is a "feasible hypothesis". They do not assert that there is sufficient evidence to show that it is factually correct. (Crain, 1999) As of 2006, no known experiments or studies have yet been attempted.

Contents 1 Rationale 2 Circumstantial evidence 3 Social controversy 4 Notes 5 See also 6 External links

[edit] Rationale

Cochran points out that genetic conditions which strongly effect the ability to reproduce appear to fall into two categories - those that are very rare (effecting about 1 in 10,000 births or less), and those that result from selective advantage i.e. heterozygote advantage, the most famous example being Sickle Cell Anemia. Homosexuality is reportedly present in more than 1 in 100 people. Assuming it is not caused by a recent mutation or the result of heterozygote advantage, a reasonable explanation would be that it is caused by a germ or other environmental factor.

Cochran claims that theories of the cause of narcolepsy - that it is an auto-immune disease triggered by a virus^[1][2] - make the mechanism of selective brain modification plausible. He also claims that only humans and sheep exhibit homosexual behavior at population levels near 1% or greater. He says that given their physical proximity, it would be plausible to expect a pathogen that affected both species.

Proponents cite increasing evidence^[3] that some cases of Schizophrenia may be linked to exposure with Toxoplasma gondii. Other studies suggest that a variety of mood disorders may be linked to Borna Virus.^[4][5]

Proponents also cite the cases of the bacterium Helicobacter pylori, which was recently discovered to contribute to most peptic ulcers; the bacterium Chlamydia pneumoniae, which may cause atherosclerosis; Nanobacter, which might cause kidney stones; and various viruses linked to cervical cancer and hepatocellular carcinoma (liver cancer). (Crain, 1999)

[edit] Circumstantial evidence

Although they make no claims and it was not the goal of their 2006 study, “Childhood Family Correlates of Heterosexual and Homosexual Marriages: A National Cohort Study of Two Million Danes,” ^[6] researchers Morten Frisch and Anders Hviid may have published the first piece of data supporting the Gay Germ theory. Their study found that people born in large cities were significantly more likely to marry a same-sex partner than those born in rural areas. “The relationship is linear; the more urban one’s birth place, the more likely one is to marry homosexually and, conversely, the more rural one’s birth place, the more likely one is to marry heterosexually.” “Our study may be the first to show that birth place or some correlate thereof influences marital choices in adulthood.” The study did not attempt to determine how closely rates of gay marriage and homosexuality in the general population correlate. Although Denmark is a physically small nation cultural variations between urban and rural areas are one possible explanation for the difference. Findings in other areas of mental health^[7] make an infectious agent another plausible cause.

According to Greg Cochran data found in the General Social Survey shows a similar patern in the United States.^[8] “…the prevalence of homosexuality probably varies a lot. It seems to be considerably more common in young men who grew up in urban areas than in rural areas, something like a factor of three, which is also true of Schizophrenia.”

[edit] Social controversy

Many scientists, such as William Byne who is a brain researcher at the Mount Sinai School of Medicine in New York, suggest that "Cochran and Ewald are guilty of pathologizing homosexuality" (in the words of Crain, 1999). In contrast, Michael Bailey, professor of psychology at Northwestern University, asks, "Suppose we found that a form of genius was also caused by a virus. Would that mean that genius is a disease?" (Crain, 1999) Cochran and Ewald point out that some bacteria are more symbiotic in nature, such as certain species which aid digestion in mammals.

The Diagnostic and Statistical Manual of Mental Disorders does not classify homosexuality as a disease, and the American Psychological Association affirms that it is not. These assertions mainly consider the ability of a person to function as a happy, healthy member of society, not any particular theory about the determinants of sexual orientation.

In social debates about the morality of homosexual acts and the legal regimes that should regulate or protect sexual behaviors or identities, different sides often make different judgments about whether or not atypical sexual orientations are "diseases," or "differences" (like race or eye color). (Some also believe that homosexuality is a choice, not an inherent condition.) Participants in the debate are thus concerned about empirical theories that may influence public opinion one way or the other.

Cochran asks, rhetorically, "Should we drop a theory that has a chance of being correct on the grounds that it might upset people?...The facts of the natural world don’t seem to care what we feel, and our feelings don’t always help in figuring out how things really work." (Crain, 1999)

[edit] Notes

[edit] See also

• Environment, choice, and sexual orientation
• Genetics and sexual orientation
• Societal attitudes towards homosexuality

[edit] External links

• An Evolutionary Look at Human Homosexuality by Gregory Cochran (original publication date unknown)
• A New Germ Theory. Originally published in The Atlantic Monthly magazine, Feburary 1999
• "Gay Germ" by Caleb Crain. Originally published in Out magazine, August 1999, pp. 46–49.