Homosexuality is psychological and not biological.

"In the interests of clarity and ease, both for myself and the readers, perhaps when you make an affirmative claim you might wish to quote what you feel is the key portion from a website or study, rather than merely several links to various."Sue, should be no problem."But can could scientists take the gene samples of babies and determine which were hetro and which would be homosexual?"With a high degree of accuracy, yes."An algorithm using epigenetic information from just nine regions of the human genome can predict the sexual orientation of males with up to 70 percent accuracy" (1)The accuracy rate isn't near absolute, because homosexuality isn't entirely genetic in origin. That, and the fact that homosexuality can be predicted from genes (particularly with such a high degree of accuracy) shows that they play some role in its cause."It should be clear by now that whatever homosexuality is rooted in that thing is not biological or genetic."In addition to the prior evidence (which should be more than sufficient), there is even more data that supports a partly genetic view of homosexuality.For example, one study found X-chromosomal linkages between homosexual men:"DNA linkage analysis of a selected group of 40 families in which there were two gay brothers and no indication of nonmaternal transmission revealed a correlation between homosexual orientation and the inheritance of polymorphic markers on the X chromosome in approximately 64 percent of the sib-pairs tested." (2)"From an evolutionary perspective you might wonder why a male 'born gay' would also produce semen?"There is an evolutionary precedent for why male homosexuality exists. One study found that female relatives of homosexual men tend to be more fertile than average."We observed that the maternal aunts and grandmothers of homosexual probands were significantly more fecund compared with the maternal aunts and maternal grandmothers of the heterosexual probands." (3)This suggests that the genes influencing male homosexuality have a different effect on women (increased fecundity), to the degree that the effect of increased female fertility offset the selective pressure against male homosexuality."This would further indicate to me that no baby is born 'genetically gay'."As my sources show above, it's unlikely one's sexuality is determined entirely by genetics. That said, it'd be silly to rule out the demonstrated impact genetics have on the issues entirely."The much higher instances of drug use (self medicating even), the high risk taking behaviours, casual disregard for consequence, greater instances of self harm and suicidal ideation, sexual promiscuity but difficulty in sustaining relationships, commonly highly sensitive to any criticism while being fiercely critical of others."These issues being more common in homosexuals than heterosexuals is likely owed to other factors, not homosexuality itself.At least some of these issues (the abnormal suicide rate for example) are definitively known to be largely caused by social factors:"Several nonrandom studies have found an association between parental rejection because of sexual orientation and higher risk of suicide attempts among LGB youth (D'Augelli, Grossman, Salter, et al., 2005; D'Augelli, Hershberger, & Pilkington, 2001; Remafedi et al., 1991; Ryan, Huebner, Diaz, & Sanchez, 2009). One study of White and Latino LGB young adults aged 21–25 (Ryan et al., 2009) found that those who experienced frequent rejecting behaviors by their parents or caregivers during adolescence were over eight times more likely to report making a suicide attempt than those with accepting parents." (4)If there's any evidence that these are directly caused by homosexuality itself, directly, then it has not been presented. Furthermore, evidence that the final parallel is more common in homosexuals than in heterosexuals ("commonly highly sensitive to any criticism while being fiercely critical of others") remains to be provided by Pro.Sources:1) http://www.ashg.org...2) http://www.ncbi.nlm.nih.gov...3) http://journals.plos.org...4) http://www.ncbi.nlm.nih.gov...