The evidence for biological causation of homosexuality raises important issues: Would people be more accepting of homosexuality if a clear biological basis for it were estab­lished? Recent research indicates that people who do believe that homosexuality is biologi­cally based—that people are born gay—have more positive feelings toward homosexuals and are more supportive of gay civil rights, including marriage, than are people who believe that homosexuality is learned or an individual choice (Jones, 2011). How common is the belief that homosexuality is innate? Approximately 40% of the population thinks a person is born gay, and 42% believe it is due to upbringing and environment (Jones, 2011).

If homosexuality were labeled as biologically "defective," would that promote medi­cal treatments during pregnancy or after birth to eliminate factors that contribute to its development? In 2010 a controversy developed that emphasized this question. CAH (congenital adrenal hyperplasia) is a genetic disorder in girls that creates unusually high levels of exposure to androgens during prenatal development and childhood. These girls engage less in typical female gender-role behaviors, they develop large clitorises, facial hair, and deep voices, and they are more likely to have lesbian and bisexual orientations. When the steroid desamethasone is given during pregnancy and during childhood, it counters the masculinizing effects of the genetic disorder. The controversy centered on whether the treatments were motivated too strongly by social pressure for gender-role conformity and heterosexuality (Begley, 2010; Dreger et al., 2010).