>>14134175In the premodern era most humans were infested with parasites, even today if you go to the third world most people have been colonised by Ascaris lumbricoides for instance. He doesn't claim that it's Toxoplasma in particular that causes homosexuality but even if he did that is more easily explained by the fact that Toxoplasma is a more pathogenic and opportunistic parasite which is characteristic of infection of people with AIDS, whom as we know, are most of the time homosexual. So it is difficult to distinguish whether homosexuals are simply more prone to Toxoplasma infection rather than Toxoplasma causing homosexuality.
It is my view that there is merit to the view that at least for some significant subgroup of homosexuals, lack of exposure to prenatal androgens may cause a lack of full development of certain parts of the brain that are demonstrably smaller in homosexuals (e.g. sexually dimorphic nucleus as per research by Simon LeVay) and closer to that of a female. Like many clinical phenomena however, there are probably many different phenotypes that underlie a common clinical presentation. Some individuals may have become homosexual because of this lack of prenatal exposure to androgen (or maybe even post-natal up to puberty) another homosexual may have been traumatised into the sexuality by prior sexual trauma, some others may in-fact have been hypermasculanised at some point during their endocrine development.
What is clear though is that homosexuality is a pathologic state; in so far as it is a deviation from the norm that prevents the expression of normal biological function (reproduction). That is not a moral claim, something can be pathological yet we as a society can still accept those people within our midst, take the person with Down syndrome, or cystic fibrosis, they have a pathology that prevents them from expressing normal biological function yet that doesn't mean people with cystic fibrosis or Down syndrome are morally inferior.