Sexual fluidity

Sexual fluidity is one or more changes in sexuality or sexual identity (sometimes known as sexual orientation identity). Sexual orientation is stable for the vast majority of people, but some research indicates that some people may experience change in their sexual orientation, and this is more likely for women than men. There is no scientific evidence that sexual orientation can be changed through psychotherapy. Sexual identity can change throughout an individual's life, and does not have to align with biological sex, sexual behavior, or actual sexual orientation.

According to scientific consensus, sexual orientation is not a choice. Although no single theory on the cause of sexual orientation has yet gained widespread support, scientists favor biological theories, especially for explaining male sexual orientation. Research over several decades has demonstrated that sexual orientation can be at any point along a continuum, from exclusive attraction to the opposite sex to exclusive attraction to the same sex.

Use of the term sexual fluidity has been attributed to psychologist Lisa M. Diamond, who observed that many women's attractions towards women and men changed over time, although changes were modest (1 kinsey scale point, on average). The results of a large-scale, longitudinal study by Savin-Williams, Joyner, and Rieger (2012) indicated that stability of sexual orientation identity over a six-year period was more common than change, and that stability was greatest among men and those identifying as heterosexual. While stability is more common than change, change in sexual orientation identity does occur and the vast majority of research indicates that female sexuality is more fluid than male sexuality. This could be attributed to females' higher erotic plasticity or to sociocultural factors that socialize women to be more open to change. Due to the gender differences in the stability of sexual orientation identity, male and female sexuality may not function via the same mechanisms. Researchers continue to analyze sexual fluidity to better determine its relationship to sexual orientation subgroups (i.e., bisexual, lesbian, gay, etc.).

Often, sexual orientation and sexual 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. 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, 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). Scientists and mental health professionals generally do not believe that sexual orientation is a choice.

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." They say that "sexual orientation identity—not sexual orientation—appears to change via psychotherapy, support groups, and life events." The American Psychiatric Association says individuals may "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.

In the first decade of the 2000s, psychologist Lisa M. Diamond studied 80 non-heterosexual women over several years. She found that in this group, changes in sexual identity were common, although they were typically between adjacent identity categories (such as 'lesbian' and 'bisexual'). Some change in self-reported sexual feeling occurred among many of the women, but it was small, only averaging about 1 point on the Kinsey scale on average. The range of these women's potential attractions was limited by their sexual orientations, but sexual fluidity permitted movement within that range.

In her book Sexual Fluidity, which was awarded with the 2009 Lesbian, Gay, Bisexual, and Transgender Issues Distinguished Book Award by Division 44 of the American Psychological Association, Diamond speaks of female sexuality and trying to go beyond the language of "phases" and "denial", arguing that traditional labels for sexual desire are inadequate. For some of 100 non-heterosexual women she followed in her study over a period of 10 years, the word bisexual did not truly express the versatile nature of their sexuality. Diamond calls "for an expanded understanding of same-sex sexuality."

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." She suggested that sexual orientation is a phenomenon more connected with female non-heterosexual sexuality, stating, "whereas sexual orientation in men appears to operate as a stable erotic 'compass' reliably channeling sexual arousal and motivation toward one gender or the other, sexual orientation in women does not appear to function in this fashion... As a result of these phenomena, women's same-sex sexuality expresses itself differently from men's same-sex sexuality at every stage of the life course."