This section will cover the science behind the LGB in LGBTQ. I will talk more about gender in the upcoming non-binary and transgender chapter.

      Sometimes people are reluctant to talk about the science behind sexual orientation because they fear a dark future where gayness is “cured” by gene selection, or perhaps they think scientists are searching for a cure, or that a scientific explanation means that being gay is “not normal,” a message gay people already hear quite enough. I certainly understand all these concerns, because there have been too many times in human history where there have been ethnic or religious cleansings. Societies have always preferred a certain set of traits, and the desire is strong to select for those traits, whatever they may be. So this is not just a LGBTQ concern, it is a concern of any person who has any characteristic that doesn’t conform to whatever the impossible standards are of a given society. My take on the scientific research is that it is actually very reassuring to many LGBTQ people and their families. Our society is still so homophobic and unforgiving that it is a relief to just be able to know, “I was born this way. This is who I am.”

      The hereditary (a set of characteristics passed through families) link of LGB has been established for decades now, but scientists knew it was not a strictly genetic link, because there are identical twins who have different sexual orientations. Scientists from the National Institute for Mathematical and Biological Synthesis theorize that homosexuality seems to have an epigenetic, not a genetic link. LGB is linked to epi-marks—conduits of information that control the expression of certain genes. These epi-marks usually disappear between generations. In LGB people, the epi-marks don’t disappear. Instead, they pass from father-to-daughter or mother-to-son, William Rice, a biologist at the University of California at Santa Barbara and lead author of the study, said. 19

      “There is compelling evidence that epi-marks contribute to both the similarity and dissimilarity of family members, and can therefore feasibly contribute to the observed familial inheritance of homosexuality and its low concordance between [identical] twins,” Rice said in a 2012 US World and News Report article.

      Rice’s theory makes total sense; if homosexuality was just a genetic trait, scientists would expect the trait to become rarer, because homosexuals would probably not reproduce. But epi-marks helped the parents of the LGB children when they themselves were in the womb. Epi-marks protected the fathers of LGB children from underexposure to testosterone, and protected the mothers of LGB children from overexposure to testosterone while they were developing embryos and fetuses themselves. Rice also said that homosexual behavior is common in the animal kingdom and has been observed in black swans, penguins, sheep, and other animals.

      But epi-marks aren’t the whole story. Sex hormones in prenatal life also play a role. Girls born with congenital adrenal hyperplasia, which results in increased levels of male sex hormones, often report same-gender attraction as teenagers and young adults.20 There are also cases of genetic males who, through accidents, or having been born without a penis, were subjected to sex change and raised as girls.21 As teenagers and young adults, these men are typically attracted to girls and women. The fact that you cannot make a straight genetic male sexually attracted to another male by raising him as a female makes any “choice” or social theory of sexual orientation seem pretty unlikely.

      A 2015 article in the Guardian22 said that brain scans of gay and heterosexual people show their brains also appear to be organized in different ways. Gay men appear on average to have more female typical organization in brain pattern responses, and lesbian women are somewhat more male typical in their responses. Scans also show differences in cognition between gays and straights. Not bad or worse, just different. But these scans might also help explain why so many LGB people are talented business people, athletes, and original artists. Differences in cognition may mean differences in psychology, personality, and relationships, and difference can also mean creativity and original problem-solving, which are real assets in any society. I like to think that though things are hard for our children, they may have also received gifts along with their challenges.

      Another important note from The Guardian article: It’s good to remember that sexual orientation is not a behavior, nor is it the sex acts someone may enjoy. People have had sex with people of the same or different genders without labeling themselves, and the sex acts might still feel good or be enjoyable. Sexual orientation is a “pattern of desire,” it’s who you fall in love with, who you want to spend time with. It’s not just who you want to have sex with.

      Do’s and Don’ts