The existence or absence of a protein can have an effect on things like alcohol tolerance or mood.
Affecting something is not the same as having complete control over it.
(The fourth option, that gay people have no choice but to be gay, but should be punished for it anyway, is morally unthinkable.) What does science tell us about sexual preference?
Genes We know, from many twin and adoption studies, that sexual preference has a genetic component.
Fw-300 #ya-qn-sort h2 /* Breadcrumb */ #ya-question-breadcrumb #ya-question-breadcrumb i #ya-question-breadcrumb a #bc .ya-q-full-text, .ya-q-text #ya-question-detail h1 html[lang="zh-Hant-TW"] .ya-q-full-text, html[lang="zh-Hant-TW"] .ya-q-text, html[lang="zh-Hant-HK"] .ya-q-full-text, html[lang="zh-Hant-HK"] .ya-q-text html[lang="zh-Hant-TW"] #ya-question-detail h1, html[lang="zh-Hant-HK"] #ya-question-detail h1 /* Trending Now */ /* Center Rail */ #ya-center-rail .profile-banner-default .ya-ba-title #Stencil . Bgc-lgr .tupwrap .comment-text /* Right Rail */ #Stencil .
Fw-300 .qstn-title #ya-trending-questions-show-more, #ya-related-questions-show-more #ya-trending-questions-more, #ya-related-questions-more /* DMROS */ .This led to media headlines about the possibility of the existence of a “gay gene” and discussions about the ethics of aborting a “gay” fetus.There have also been headlines about an “alcoholism gene”, which makes people become alcoholics, and a “warrior gene”, which makes people unusually aggressive. Genes regulate the production of amino acids, which combine to form proteins.Male homosexual behavior was expected in ancient Athens.Today, ritual male homosexuality plays an important role in some cultures in New Guinea.It did, however, show that in gay men, neurons in the INAH3 are packed more closely together than in straight men.PET and MRI studies performed in 2008 have shown that the two halves of the brain are more symmetrical in homosexual men and heterosexual women than in heterosexual men and homosexual women.A later study, which was performed in 2001, showed that HIV status has no significant effect on the INAH3.This study, which also used brain tissue from autopsies, did not reveal any significant difference between the size of the INAH3 in gay men and straight men.These studies have also revealed that connections in the amygdalas of gay men resemble those of straight women; in gay women, connections in the amygdala resemble those of straight men.The amygdala has many receptors for sex hormones and is associated with the processing of emotions.