Environment and sexual orientation

The study of the environment and sexual orientation is research into possible environmental influences on the development of human sexual orientation. Some researchers distinguish environmental influences from hormonal influences,[1] while others include biological influences such as prenatal hormones as part of environmental influences.[2]

Scientists do not know the exact cause of sexual orientation, but they believe that it is the result of a complex interplay of genetic, hormonal, and environmental influences.[3][4][5] Unlike sexual orientation identity, they do not view sexual orientation as a choice.[3][4][6]

Although there is no substantial evidence which suggests parenting or early childhood experiences play a role in sexual orientation,[7][8] some studies have linked parenting or familial environment to non-heterosexual identities,[2][9] as well as childhood gender nonconformity and homosexuality.[10][11][12]

Sexual orientation compared with sexual orientation identity

Often, sexual orientation and sexual orientation identity are not distinguished, which can impact accurately assessing sexual identity and whether or not sexual orientation is able to change; sexual orientation identity can change throughout an individual's life, and may or may not align with biological sex, sexual behavior or actual sexual orientation.[13][14][15] While the Centre for Addiction and Mental Health and American Psychiatric Association state that sexual orientation is innate, continuous or fixed throughout their lives for some people, but is fluid or changes over time for others,[16][17] the American Psychological Association distinguishes between sexual orientation (an innate attraction) and sexual orientation identity (which may change at any point in a person's life).[18] Scientists and mental health professionals generally do not believe that sexual orientation is a choice.[1][6]

The American Psychological Association states that "sexual orientation is not a choice that can be changed at will, and that sexual orientation is most likely the result of a complex interaction of environmental, cognitive and biological factors...is shaped at an early age...[and evidence suggests] biological, including genetic or inborn hormonal factors, play a significant role in a person's sexuality".[4] They say that "sexual orientation identity—not sexual orientation—appears to change via psychotherapy, support groups, and life events".[18] The American Psychiatric Association says "individuals maybe become aware at different points in their lives that they are heterosexual, gay, lesbian, or bisexual" and "opposes any psychiatric treatment, such as 'reparative' or 'conversion' therapy, which is based upon the assumption that homosexuality per se is a mental disorder, or based upon a prior assumption that the patient should change his/her homosexual orientation". They do, however, encourage gay affirmative psychotherapy.[17]

Scholar Lisa Diamond, when reviewing research on lesbian and bisexual women's sexual identities, stated that studies find "change and fluidity in same-sex sexuality that contradict conventional models of sexual orientation as a fixed and uniformly early-developing trait".[19]