Editing Sexual fluidity

{{short description|Changes in sexuality or sexual identity}}
'''Sexual fluidity''' is one or more changes in [[sexuality]] or [[sexual identity]] (sometimes known as sexual orientation identity). [[Sexual orientation]] is stable and unchanging 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 for men.<ref name="Change">
*{{cite journal|last1=Bailey|first1=J. Michael|last2=Vasey|first2=Paul|last3=Diamond|first3=Lisa|author4-link=Marc Breedlove|last4=Breedlove|first4=S. Marc|last5=Vilain|first5=Eric|last6=Epprecht|first6=Marc|title=Sexual Orientation, Controversy, and Science|journal=Psychological Science in the Public Interest|date=2016|volume=17|issue=2|pages=45–101|doi=10.1177/1529100616637616|pmid=27113562|url=https://www.researchgate.net/publication/301639075|quote=Sexual fluidity is situation-dependent flexibility in a person’s sexual responsiveness, which makes it possible for some individuals to experience desires for either men or women under certain circumstances regardless of their overall sexual orientation....We expect that in all cultures the vast majority of individuals are sexually predisposed exclusively to the other sex (i.e., heterosexual) and that only a minority of individuals are sexually predisposed (whether exclusively or non-exclusively) to the same sex.|doi-access=free}}
*{{cite book|author1=Seth J. Schwartz|author2=Koen Luyckx|author3=Vivian L. Vignoles|title=Handbook of Identity Theory and Research|publisher= [[Springer Science & Business Media]]|isbn=978-1441979889|year=2011|page=652|access-date=February 18, 2016|url=https://books.google.com/books?id=LkREWoAUrAUC&pg=PA652|quote=Modern scholarship examining the stability of sexual orientation also seems to support our conceptualizations of sexual orientation, sexual orientation identity, and sexual identity (e.g., Diamond, 2003a; Horowitz & Necomb, 2001; Rosario, Schrimshaw, Hunter, & Braun, 2006, see Savin-Williams, Chapter 28, this volume). Specifically, some dimensions of sexual identity, such as relationships, emotions, behaviors, values, group affiliation, and norms, appear to be relatively fluid; by contrast, sexual orientation [i.e., an individual's patterns of sexual, romantic, and affectional arousal and desire for other persons based on those persons' gender and sex characteristics (APA Task Force on Appropriate Therapeutic Responses to Sexual orientation, 2009)] has been suggested to be stable for a majority of people across the lifespan (Bell, Weinberg, & Hammersmith, 1981; Ellis & Ames, 1987; Haldeman, 1991; Money, 1987).}}
*{{cite book|author1=Dennis Coon|author2=John O. Mitterer|title=Introduction to Psychology: Gateways to Mind and Behavior with Concept Maps and Reviews|publisher=[[Cengage Learning]]|isbn=978-1111833633|year=2012|page=372|access-date=February 18, 2016|url=https://books.google.com/books?id=EYwjCQAAQBAJ&pg=PA372|quote=Sexual orientation is a deep part of personal identity and is usually quite stable. Starting with their earliest erotic feelings, most people remember being attracted to either the opposite sex or the same sex. [...] The fact that sexual orientation is usually quite stable doesn't rule out the possibility that for some people sexual behavior may change during the course of a lifetime.}}
*{{cite journal | author = American Psychological Association | year = 2012 | title = Guidelines for Psychological Practice With Lesbian, Gay, and Bisexual Clients | journal = [[American Psychologist]] | volume = 67 | issue = 1 | pages = 10–42 | doi= 10.1037/a0024659 | pmid = 21875169 | quote = [S]ome research indicates that sexual orientation is fluid for some people; this may be especially true for women (e.g., Diamond, 2007; Golden, 1987; Peplau & Garnets, 2000). [...] Therapeutic efforts to change sexual orientation have increased and become more visible in recent years (Beckstead & Morrow, 2004). Therapeutic interventions intended to change, modify, or manage unwanted nonheterosexual orientations are referred to as “sexual orientation change efforts” (SOCE; APA, 2009b). [...] Reviews of the literature, spanning several decades, have consistently found that efforts to change sexual orientation were ineffective (APA, 2009b; Drescher, 2001; Haldeman, 1994; T. F. Murphy, 1992).|access-date=June 23, 2019|url=https://www.apa.org/pubs/journals/features/amp-a0024659.pdf}}
*{{cite book|author1=Eric Anderson|author2=Mark McCormack|title=The Changing Dynamics of Bisexual Men's Lives|chapter=Measuring and Surveying Bisexuality|publisher= [[Springer Science & Business Media]]|isbn=978-3-319-29412-4|year=2016|page=47|access-date=June 22, 2019|chapter-url=https://books.google.com/books?id=7_AgDAAAQBAJ&pg=PA47|quote=[R]esearch suggests that women's sexual orientation is slightly more likely to change than men's (Baumeister 2000; Kinnish et al. 2005). The notion that sexual orientation can change over time is known as ''sexual fluidity''. Even if sexual fluidity exists for some women, it does not mean that the majority of women will change sexual orientations as they age – rather, sexuality is stable over time for the majority of people.}}</ref> There is no scientific evidence that sexual orientation can be changed through [[psychotherapy]].<ref name="APA2012">{{cite journal | author = American Psychological Association | year = 2012 | title = Guidelines for Psychological Practice With Lesbian, Gay, and Bisexual Clients | journal = [[American Psychologist]] | volume = 67 | issue = 1 | pages = 10–42 | doi= 10.1037/a0024659 | pmid = 21875169 | quote = Therapeutic efforts to change sexual orientation have increased and become more visible in recent years (Beckstead & Morrow, 2004). Therapeutic interventions intended to change, modify, or manage unwanted nonheterosexual orientations are referred to as "sexual orientation change efforts" (SOCE; APA, 2009b). [...] Reviews of the literature, spanning several decades, have consistently found that efforts to change sexual orientation were ineffective (APA, 2009b; Drescher, 2001; Haldeman, 1994; T. F. Murphy, 1992).|access-date=June 23, 2019|url=https://www.apa.org/pubs/journals/features/amp-a0024659.pdf}}</ref><ref name="RCP">{{cite web|title=Royal College of Psychiatrists' Position Statement on Sexual Orientation|publisher=[[Royal College of Psychiatrists]]|access-date=June 21, 2019|url=https://www.rcpsych.ac.uk/pdf/PS02_2014.pdf|quote=The College believes strongly in evidence-based treatment. There is no sound scientific evidence that sexual orientation can be changed. Systematic reviews carried out by both the APA and Serovich ''et al'' suggest that studies which have shown conversion therapies to be successful are seriously methodologically flawed.}}</ref> Sexual identity can change throughout an individual's life, and may or may not align with [[biological sex]], [[sexual behavior]] or actual sexual orientation.<ref name="Sinclair">Sinclair, Karen, About Whoever: The Social Imprint on Identity and Orientation, NY, 2013 {{ISBN|9780981450513}}</ref><ref name="Rosario et al.">{{cite journal | last1 = Rosario | first1 = M. | last2 = Schrimshaw | first2 = E. | last3 = Hunter | first3 = J. |last4 = Braun | first4 = L. | year = 2006 | title = Sexual identity development among lesbian, gay, and bisexual youths: Consistency and change over time | journal = Journal of Sex Research | volume = 43 | issue = 1| pages = 46–58 | doi=10.1080/00224490609552298| pmid = 16817067 | pmc = 3215279 }}</ref><ref name="Concordance/discordance in SO">{{cite journal|first=Michael W.|last=Ross|author2=Essien, E. James |author3=Williams, Mark L. |author4= Fernandez-Esquer, Maria Eugenia. |title=Concordance Between Sexual Behavior and Sexual Identity in Street Outreach Samples of Four Racial/Ethnic Groups|publisher=American Sexually Transmitted Diseases Association|year=2003|pmid=12567166|journal=Sexually Transmitted Diseases|volume=30|issue=2|pages=110–113|doi=10.1097/00007435-200302000-00003|s2cid=21881268}}</ref>

Sexual orientation is not a choice.<ref name="pediatrics2004">{{cite journal |doi=10.1542/peds.113.6.1827 |author=Frankowski B.L. |author2=American Academy of Pediatrics Committee on Adolescence|title=Sexual orientation and adolescents |journal=[[Pediatrics (journal)|Pediatrics]]|volume=113 |issue=6 |pages=1827–32 |date=June 2004|pmid=15173519|url=http://pediatrics.aappublications.org/content/113/6/1827.long|quote= The mechanisms for the development of a particular sexual orientation remain unclear, but the current literature and most scholars in the field state that one’s sexual orientation is not a choice; that is, individuals do not choose to be homosexual or heterosexual. A variety of theories about the influences on sexual orientation have been proposed. Sexual orientation probably is not determined by any one factor but by a combination of genetic, hormonal, and environmental influences.|doi-access=free}}</ref><ref name="Kersey-Matusiak">{{cite book|author=Gloria Kersey-Matusiak|title=Delivering Culturally Competent Nursing Care |publisher=[[Springer Publishing Company]]|isbn=978-0826193810|year=2012|page=169|access-date=February 10, 2016|url=https://books.google.com/books?id=X8O_wGedAYoC&pg=PA169|quote=Most health and mental health organizations do not view sexual orientation as a 'choice.'}}</ref><ref name="Lamanna">{{cite book|author1=Mary Ann Lamanna|author2=Agnes Riedmann|author3=Susan D Stewart|title=Marriages, Families, and Relationships: Making Choices in a Diverse Society|publisher=[[Cengage Learning]]|isbn=978-1305176898|year=2014|page=82|access-date=February 11, 2016|url=https://books.google.com/books?id=fofaAgAAQBAJ&pg=PA82|quote=The reason some individuals develop a gay sexual identity has not been definitively established &nbsp;– nor do we yet understand the development of heterosexuality. The American Psychological Association (APA) takes the position that a variety of factors impact a person's sexuality. The most recent literature from the APA says 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 (American Psychological Association 2010).}}</ref> There is no consensus on the exact cause of developing a sexual orientation, but [[Genetics|genetic]], [[hormonal]], social and cultural influences have been examined.<ref name="Lamanna"/><ref>{{cite web|url=http://www.apa.org/topics/lgbt/orientation.aspx|title=Answers to Your Questions For a Better Understanding of Sexual Orientation and Homosexuality|publisher=American Psychological Association|access-date=February 9, 2016}}</ref><ref name="Stuart">{{cite book|author=Gail Wiscarz Stuart|title=Principles and Practice of Psychiatric Nursing|publisher=[[Elsevier Health Sciences]]|isbn=978-0323294126|year=2014|page=502|access-date=February 11, 2016|url=https://books.google.com/books?id=ivALBAAAQBAJ&pg=PA502|quote=No conclusive evidence supports any one specific cause of homosexuality; however, most researchers agree that biological and social factors influence the development of sexual orientation.}}</ref> Scientists believe that it is caused by a complex interplay of genetic, hormonal, and [[Environment and sexual orientation|environmental influences]].<ref name="pediatrics2004"/><ref name="Lamanna"/><ref name="Stuart"/> Although no single theory on the cause of sexual orientation has yet gained widespread support, scientists favor [[Biology and sexual orientation|biologically-based theories]].<ref name="pediatrics2004"/><ref name="Bailey">{{cite journal|vauthors=Bailey JM, Vasey PL, Diamond LM, Breedlove SM, Vilain E, Epprecht M|title=Sexual Orientation, Controversy, and Science |journal=[[Psychological Science in the Public Interest]]|volume=17|issue=21|date=2016|doi=10.1177/1529100616637616|pmid=27113562|pages=45–101|doi-access=free}}</ref> Research over several decades has demonstrated that sexual orientation can be at any point along [[heterosexual-homosexual continuum|a continuum]], from exclusive attraction to the opposite sex to exclusive attraction to the same sex.<ref name="AmPsycholAssn-whatis">{{cite web|title=Sexual orientation, homosexuality and bisexuality|publisher=[[American Psychological Association]]|access-date=August 10, 2013|url=http://www.apa.org/helpcenter/sexual-orientation.aspx|archive-date=August 8, 2013|archive-url=https://web.archive.org/web/20130808032050/http://www.apa.org/helpcenter/sexual-orientation.aspx}}</ref>

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.<ref name="Savin-Williams, R.C. 2012">{{cite journal | last1 = Savin-Williams | first1 = R.C. | last2 = Joyner | first2 = K. | last3 = Rieger | first3 = G. | year = 2012 | title = Prevalence and stability of self-reported sexual orientation identity during young adulthood | journal = Archives of Sexual Behavior | volume = 41| issue = 1| pages = 1–8 | doi = 10.1007/s10508-012-9913-y | pmid=22302504| s2cid = 43225099 }}</ref> While stability may be 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.<ref name="ReferenceC"/> Due to the [[gender differences]] in the stability of sexual orientation identity, male and female sexuality are not treated as functioning 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.).

Use of the term ''sexual fluidity'' has been attributed to [[Lisa M. Diamond]], especially with regard to female sexuality.<ref name="Weiten">{{cite book|author1=Wayne Weiten|author2=Dana S. Dunn|author3=Elizabeth Yost Hammer|title=Psychology Applied to Modern Life: Adjustment in the 21st Century|publisher=[[Cengage Learning]] |isbn=978-1337517072 |year=2016 |page=341 |access-date=April 4, 2017|url=https://books.google.com/books?id=wvO5DQAAQBAJ&pg=PA341}}</ref><ref name="Crooks">{{cite book|author1=Robert L. Crooks|author2=Karla Baur|title=Our Sexuality|publisher=[[Cengage Learning]]|isbn=978-1305887428|year=2016|page=298|access-date=April 4, 2017|url=https://books.google.com/books?id=isIaCgAAQBAJ&pg=PT298}}</ref> The term and the concept gained recognition in the psychological profession{{citation needed|date=May 2021}} and in the media.<ref>[https://www.theguardian.com/society/2019/feb/14/the-pansexual-revolution-how-sexual-fluidity-became-mainstream The pansexual revolution: how sexual fluidity became mainstream], Gaby Hinsliff, "The Guardian", Feb. 14, 2019, accessed May 20, 2021</ref>

==Background==
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.<ref name="Sinclair"/><ref name="Rosario et al."/><ref name="Concordance/discordance in SO"/> 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,<ref>{{cite web|title=Question A2: Sexual orientation |url=http://knowledgex.camh.net/amhspecialists/Screening_Assessment/assessment/ARQ2/Pages/arq2_question_a2.aspx |publisher=Centre for Addiction and Mental Health |access-date=3 February 2015 |url-status=dead |archive-url=https://web.archive.org/web/20141228033920/http://knowledgex.camh.net/amhspecialists/Screening_Assessment/assessment/ARQ2/Pages/arq2_question_a2.aspx |archive-date=28 December 2014 }}</ref><ref name="What is">[http://www.psychiatry.org/lgbt-sexual-orientation "LGBT-Sexual Orientation: What is Sexual Orientation?"] {{webarchive|url=https://web.archive.org/web/20140628094701/http://www.psychiatry.org/lgbt-sexual-orientation |date=2014-06-28 }}, the official web pages of APA. Accessed April 9, 2015</ref> 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).<ref name=apa2009>{{cite web |title=Appropriate Therapeutic Responses to Sexual Orientation|publisher=[[American Psychological Association]]|pages=63, 86|date=2009|access-date=February 3, 2015|url=http://www.apa.org/pi/lgbc/publications/therapeutic-response.pdf}}</ref> Scientists and mental health professionals generally do not believe that sexual orientation is a choice.<ref name="pediatrics2004"/><ref name="Kersey-Matusiak"/>

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."<ref name="Lamanna"/> They say that "sexual orientation identity—not sexual orientation—appears to change via psychotherapy, support groups, and life events."<ref name=apa2009/> 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|'conversion' therapy]], which is based upon the assumption that homosexuality ''[[Per se (terminology)|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]].<ref name="What is"/>

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.<ref name="Bailey"/>{{rp|56}}

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."<ref>[http://www.hup.harvard.edu/catalog.php?isbn=9780674032262&content=reviews''Sexual Fluidity - Understanding Women's Love and Desire''], Lisa M. Diamond 2009, [[Harvard University Press]]. Accessed April 6, 2015</ref>

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."<ref>{{cite journal|last1=Diamond|first1=Lisa|title=Was it a phase? Young women's relinquishment of lesbian/bisexual identities over a five-year period|journal=Journal of Personality and Social Psychology|date=2003|volume=84|issue=2|pages=352–364|doi=10.1037/0022-3514.84.2.352|pmid=12585809}}</ref> 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."<ref>{{cite journal | last1 = Diamond | first1 = Lisa M. | year = 2012 | title = The Desire Disorder in Research on Sexual Orientation in Women: Contributions of Dynamical Systems Theory | url = https://www.psych.utah.edu/people/files/diamond54a1.pdf | journal = Arch Sex Behav | volume = 41 | issue = 1| pages = 73–83 | doi = 10.1007/s10508-012-9909-7 | pmid = 22278028 | s2cid = 543731 | url-status=dead | archive-url = https://web.archive.org/web/20120518153549/http://www.psych.utah.edu/people/files/diamond54a1.pdf | archive-date = 2012-05-18 }}</ref>

==Biology and stability==

Conversion therapy (attempts to change sexual orientation) is rarely successful. In Maccio's (2011) review of sexual reorientation therapy attempts, she lists two studies that claim to have successfully converted [[gay men]] and lesbians to heterosexuals and four that demonstrate the contrary. She sought to settle the debate using a sample that was not recruited from religious organizations. The study consisted of 37 former conversion therapy participants (62.2% were male) from various cultural and religious backgrounds who currently or previously identified as lesbian, gay, or bisexual. The results indicated that there were no statistically significant shifts in sexual orientation from pre- to post-treatment. In follow-up sessions, the few changes in sexual orientation that did occur following therapy did not last. This study stands as support for the biological origin of sexual orientation, but the largely male sample population confounds the findings.<ref>Maccio, E.M. (2011). Self-reported sexual orientation and identity before and after sexual reorientation therapy. Journal of Gay and Lesbian Mental Health, 15. 242-259.</ref>

Further support for the biological origin of sexual orientation is that [[gender atypical behavior]] in childhood (e.g., a young boy playing with dolls) appears to predict homosexuality in adulthood (see [[childhood gender nonconformity]]). A longitudinal study by Drummond et al. (2008) looked at young girls with [[gender dysphoria]] (a significant example of gender atypical behavior) and found that the majority of these girls grew up to identify as bisexual or lesbian.<ref>{{cite journal | last1 = Drummond | first1 = K.D. | last2 = Bradley | first2 = S.J. | last3 = Peterson-Badali | first3 = M. | last4 = Zucker | first4 = K.J. | year = 2008 | title = A follow-up study of girls with gender identity disorder | journal = Developmental Psychology | volume = 44 | issue = 1| pages = 34–45 | doi=10.1037/0012-1649.44.1.34| pmid = 18194003 }}</ref> Many retrospective studies looking at childhood behavior are criticized for potential memory errors;<ref>{{cite journal | last1 = Rieger | first1 = G. | last2 = Linsenmeier | first2 = J.A.W. | last3 = Gygax | first3 = L. | last4 = Bailey | first4 = J.M. | year = 2008 | title = Sexual orientation and childhood gender nonconformity: evidence from home videos | journal = Developmental Psychology | volume = 44 | issue = 1| pages = 46–58 | doi=10.1037/0012-1649.44.1.46 | pmid=18194004}}</ref> so a study by Rieger, Linsenmeier, Gygax, & Bailey (2008) used home videos to investigate the relationship between childhood behaviors and adult sexual orientation. The results of this study support biological causation, but an understanding of how cultural assumptions about sexuality can affect sexual identity formation is also considered.<ref>{{cite journal | last1 = Hegarty | first1 = P. | display-authors = et al. | year = 2009 | title = Towards an LGBT-informed paradigm for children who break gender norms: comment on Drummond ''et al.'' (2008) and Rieger ''et al.'' (2008) | url = http://epubs.surrey.ac.uk/72257/5/2009%20Toward%20an%20LGBT%20affirmative%20infromed%20paradigm%20for%20children.pdf| journal = Developmental Psychology | volume = 45 | issue = 4| pages = 895–900 | doi=10.1037/a0016163| pmid = 19586166 }}</ref>

There is strong evidence for a relationship between [[fraternal birth order and male sexual orientation]], and there has been biological research done to investigate potential biological determinants of sexual orientation in men and women. One theory is the second to fourth finger ratio (2D:4D) theory. Some studies have discovered that heterosexual women had higher 2D:4D ratios than did lesbian women but the difference was not found between heterosexual and gay men.<ref>{{cite journal | last1 = Grimbos | first1 = T. | last2 = Zucker | first2 = K.J. | last3 = Dawood | first3 = K. | last4 = Burriss | first4 = R.P. | last5 = Puts | first5 = D.A. | year = 2010 | title = Sexual orientation and the second to fourth finger length ratio: a meta-analysis in men and women | url = https://semanticscholar.org/paper/e9d1dec17a9aab305fc44e26f73af0bdd73983b5| journal = Behavioral Neuroscience | volume = 124 | issue = 2| pages = 278–287 | doi=10.1037/a0018764 | pmid=20364887| s2cid = 2777884 }}</ref> Similarly, a study has shown that homosexual men have a sexually dimorphic nucleus in the anterior hypothalamus that is the size of females’.<ref>LeVay 1991 as cited in {{cite journal | last1 = Miller | first1 = E.M. | year = 2000 | title = Homosexuality, birth order, and evolution: toward an equilibrium reproductive economics of homosexuality | doi = 10.1023/a:1001836320541 | pmid = 10763427 | journal = Archives of Sexual Behavior | volume = 29 | issue = 1| pages = 1–34 | s2cid = 28241162 }}</ref> Twin and family studies have also found a genetic influence.<ref name=Bailey/>

==Changes in sexuality==
=== Demographics ===

====General====
One study by Steven E. Mock and Richard P. Eibach from 2011 shows 2% of 2,560 adult participants included in ''National Survey of Midlife Development in the United States'' reported change of sexual orientation identities after a 10-year period: 0.78% of male and 1.36% of female persons that identified themselves to be [[Heterosexuality|heterosexuals]] at the beginning of the 10-year period, as well as 63.6% of lesbians, 64.7% of bisexual females, 9.52% of gay males, and 47% of bisexual males. According to the study, "this pattern was consistent with the hypothesis that heterosexuality is a more stable sexual orientation identity, perhaps because of its [[Heteronormativity|normative status]]. However, male homosexual identity, although less stable than heterosexual identity, was relatively stable compared to the other sexual minority identities". Having only adults included in the examined group, they did not find the differences in fluidity which were affected by age of the participants. However, they stated that "research on attitude stability and change suggests most change occurs in adolescence and young adulthood (Alwin & Krosnick, 1991; Krosnick & Alwin, 1989), which could explain the diminished impact of age after that point".<ref>{{cite journal | last1 = Mock | first1 = Steven E. | last2 = Eibach | first2 = Richard P. | year = 2011 | title = Stability and Change in Sexual Orientation Identity Over a 10-Year Period in Adulthood | journal = Archives of Sexual Behavior | volume= 41 | issue = 3| pages = 641–648 | doi=10.1007/s10508-011-9761-1|url=http://midus.wisc.edu/findings/pdfs/1153.pdf | pmid=21584828| s2cid = 15771368 }}</ref>

====Males versus females====
Research generally indicates that female sexuality is more fluid than male sexuality.<ref name="Bailey et al.">{{cite journal|last1=Bailey|first1=J. Michael|last2=Vasey|first2=Paul|last3=Diamond|first3=Lisa|last4=Breedlove|first4=S. Marc|last5=Vilain|first5=Eric|last6=Epprecht|first6=Marc|title=Sexual Orientation, Controversy, and Science|journal=Psychological Science in the Public Interest|date=2016|volume=17|issue=2|pages=45–101|doi=10.1177/1529100616637616|pmid=27113562|url=https://www.researchgate.net/publication/301639075|doi-access=free}}</ref> In a seminal review of the sexual orientation literature, stimulated by the findings that the 1970s [[sexual revolution]] affected female sexuality more so than male sexuality, research by Baumeister et al. indicated that when compared to males, females have lower concordance between sexual attitudes and behaviors, and sociocultural factors affect female sexuality to a greater degree; it also found that personal change in sexuality is more common for females compared to males.<ref name="ReferenceC">{{cite journal | last1 = Baumeister | first1 = R.F. | year = 2000 | title = Gender differences in erotic plasticity: the female sex drive as socially flexible and responsive | journal = Psychological Bulletin | volume = 126 | issue = 3| pages = 347–374 | doi=10.1037/0033-2909.126.3.347 | pmid=10825779| s2cid = 35777544 }}</ref> Female sexuality (lesbian and heterosexual) changes significantly more than males on both dimensional and categorical measures of sexual orientation.<ref name="ReferenceB"/> Furthermore, the majority of homosexual women who previously identified as a different sexual orientation identified as heterosexual; whereas for males, the majority previously identified as bisexual, which the authors believe support the idea of greater fluidity in female sexuality.<ref name="ReferenceB"/> Females also report having identified with more than one sexual orientation, more often than males and are found to have higher levels of sexual orientation mobility. Females also report being bisexual or unsure of their sexuality more often than males, who more commonly report being exclusively gay or heterosexual.<ref name="auto">{{cite journal | last1 = Ott | first1 = M.Q. | last2 = Corliss | first2 = H.L. | last3 = Wypij | first3 = D. | last4 = Rosario | first4 = M. | last5 = Austin | first5 = S.B. | year = 2011 | title = Stability and change in self-reported sexual orientation identity in young people: application of mobility metrics | journal = Archives of Sexual Behavior | volume = 40 | issue = 3| pages = 519–532 | doi=10.1007/s10508-010-9691-3 | pmid=21125325 | pmc=3081371}}</ref> Over a six-year period, women have also been found to display more shifts in sexual orientation identity and were more likely to define their sexual orientation with non-exclusive terms.<ref name="Savin-Williams, R.C. 2012"/>

The social constructivist view suggests that sexual desire is a product of cultural and psychosocial processes<ref>{{cite journal | last1 = Tolman | first1 = D.L. | last2 = Diamond | first2 = L.M. | year = 2001 | title = Desegregating sexuality research: cultural and biological perspectives on gender and desire | journal = Annual Review of Sex Research | volume = 12 | pages = 33–74 | pmid = 12666736 }}</ref> and that men and women are socialized differently. This difference in socialization can explain differences in sexual desire and stability of sexual orientation. Male sexuality is centered around physical factors, whereas female sexuality is centered around sociocultural factors,<ref name="ReferenceC" /> making female sexuality inherently more open to change. The greater effect on female sexuality in 1970s sexual revolution shows that female shifts in sexual orientation identity may be due to greater exposure to moderating factors (such as the media).<ref>Diamond, 2008 as cited in {{cite journal | last1 = Savin-Williams | first1 = R.C. | last2 = Joyner | first2 = K. | last3 = Rieger | first3 = G. | year = 2012 | title = Prevalence and stability of self-reported sexual orientation identity during young adulthood | journal = Archives of Sexual Behavior | volume = 41| issue = 1| pages = 1–8 | doi = 10.1007/s10508-012-9913-y | pmid=22302504| s2cid = 43225099 }}</ref> In western culture, women are also expected to be more emotionally expressive and intimate towards both males and females. This socialization is a plausible cause of greater female sexual fluidity.<ref>{{cite journal | last1 = Rust | first1 = P.C.R. | year = 2000 | title = Bisexuality: a contemporary paradox for women | journal = Journal of Social Issues | volume = 56 | issue = 2| pages = 205–221 | doi=10.1111/0022-4537.00161}}</ref> Whether female sexuality is naturally more fluid and therefore changes from social factors or social factors cause female sexuality to be less stable is unknown.

An [[evolutionary psychology]] hypothesis proposes that bisexuality enables women to reduce conflict with other women, by promoting each others' mothering contributions, thus ensuring their reproductive success. According to this view, women are capable of forming romantic bonds with both sexes and sexual fluidity may be explained as a [[reproductive strategy]] that ensures the survival of offspring.<ref>{{cite journal | last1 = Kuhle | first1 = B.X. | last2 = Radtke | first2 = S. | year = 2013 | title = Born both ways: The alloparenting hypothesis for sexual fluidity in women | journal = Evolutionary Psychology | volume = 11 | issue = 2| page = 147470491301100202 | doi = 10.1177/147470491301100202 | doi-access = free }}</ref>

A longitudinal study concluded that stability of sexual orientation was more common than change.<ref name="Savin-Williams, R.C. 2012" /> Gender differences in the stability of sexual orientation may vary by subgroup and could possibly be related to individual differences more than gender-wide characteristics.<ref name="auto"/>

====Youth (age 14–21)====

One study that did compare the stability of youth sexual orientation identity across genders found results opposite to most done with adult samples. The study compared [[non-heterosexual]] male and female sexual orientation over a year and concluded that female youth were more likely to report consistent sexual identities than males.<ref name=RSHB06>{{cite journal | last1 = Rosario | first1 = M. | last2 = Schrimshaw | first2 = E.W. | last3 = Hunter | first3 = J. | last4 = Braun | first4 = L. | year = 2006 | title = Sexual identity development among lesbian, gay and bisexual youth: consistency and change over time | journal = The Journal of Sex Research | volume = 43 | issue = 1| pages = 46–58 | doi=10.1080/00224490609552298| pmid = 16817067 | pmc = 3215279 }}</ref> The study was conducted over a single year.

Youth appears to be when most change in sexual orientation identity occurs for females. A 10-year study compared sexual orientation as measured at four times during the study. The most change was found between the first (taken at 18 years of age) and second (taken at 20 years of age) measurements which was the only time bracket that fell during adolescence.<ref name="ReferenceA"/>

A population-based study conducted over 6 years found that nonheterosexual (gay/lesbian/bisexual) male and female participants were more likely to change sexual orientation identity than heterosexual participants.<ref>{{cite journal | last1 = Savin-Williams | first1 = R.C. | last2 = Ream | first2 = G.L. | year = 2007 | title = Prevalence and stability of sexual orientation components during adolescence and young adulthood | journal = Archives of Sexual Behavior | volume = 36 | issue = 3| pages = 385–394 | doi=10.1007/s10508-006-9088-5 | pmid=17195103| s2cid = 20819699 }}</ref> A yearlong study found that sexual identity was more stable for gay and lesbian youth participants when compared to bisexual participants.<ref name=RSHB06 /> 

The identity integration process that individuals go through during adolescence appears to be associated with changes in sexual identity; adolescents who score higher on identity integration measures are more consistent in their sexual orientation. Bisexual youths seem to take longer to form their sexual identities than do consistently homosexual or heterosexual identifying youths<ref name=RSHB06 /> so bisexuality may be seen as a transitional phase during adolescence. Rosario et al. (2006) conclude that "acceptance, commitment, and integration of a gay/lesbian identity is an ongoing developmental process that, for many youths, may extend through adolescence and beyond."<ref name=RSHB06 />

Sabra L. Katz-Wise and Janet S. Hide report in article published 2014 in "Archives of Sexual Behavior" of their study on 188 female and male young adults in the United States with a same-gender orientation, aged 18–26 years. In that cohort, sexual fluidity in attractions was reported by 63% of females and 50% of males, with 48% of those females and 34% of those males reporting fluidity in sexual orientation identity.<ref>{{cite journal | last1 = Katz-Wise | first1 = Sabra | last2 = Hide | first2 = Janet S. | year = 2014 | title = Sexual fluidity and related attitudes and beliefs among young adults with a same-gender orientation| journal = Archives of Sexual Behavior | volume = 44 | issue = 5 | pages = 1459–1470 | doi = 10.1007/s10508-014-0420-1 | pmid = 25378265 | s2cid = 21201365 }}</ref>

===Bisexuality as a transitional phase===
{{See also|Bisexuality}}
Bisexuality as a transitional phase on the way to identifying as exclusively lesbian or gay has also been studied. In a large-scale, longitudinal study, participants who identified as bisexual at one point in time were especially likely to change sexual orientation identity throughout the six-year study.<ref name="Savin-Williams, R.C. 2012" /> A second longitudinal study found conflicting results. If bisexuality is a transitional phase, as people grow older the number identifying as bisexual should decline. Over the 10-year span of this study (using a female-only sample), the overall number of individuals identifying as bisexual remained relatively constant (hovering between 50 and 60%), suggesting that bisexuality is a third orientation, distinct from homosexuality and heterosexuality and can be stable.<ref name="ReferenceA">{{cite journal | last1 = Diamond | first1 = L.M. | year = 2008 | title = Female bisexuality from adolescence to adulthood: results from a 10-year longitudinal study | journal = Developmental Psychology | volume = 44 | issue = 1| pages = 5–14 | doi=10.1037/0012-1649.44.1.5 | pmid=18194000}}</ref> A third longitudinal study by Kinnish, Strassberg, and Turner (2005) supports this theory. While sex differences in sexual orientation stability were found for heterosexuals and gays/lesbians, no sex difference was found for bisexual men and women.<ref name="ReferenceB">{{cite journal | last1 = Kinnish | first1 = K.K. | last2 = Strassberg | first2 = D.S. | last3 = Turner | first3 = C.W. | year = 2005 | title = Sex differences in the flexibility of sexual orientation: a multidimensional retrospective assessment | journal = Archives of Sexual Behavior | volume = 34 | issue = 2| pages = 173–183 | doi=10.1007/s10508-005-1795-9 | pmid=15803251| s2cid = 8545091 }}</ref>

Bisexuality remains "undertheorized and underinvestigated".<ref>{{cite journal | last1 = Saewyc | first1 = E.M. | year = 2011 | title = Research on adolescent sexual orientation: development, health disparities, stigma, and resilience | journal = Journal of Research on Adolescence | volume = 21 | issue = 1| pages = 256–272 | doi=10.1111/j.1532-7795.2010.00727.x| pmid = 27099454 | pmc = 4835230}}</ref>

== Cultural debate ==
The exploration on sexual fluidity initiated by Lisa M. Diamond presented a cultural challenge to the [[LGBT community]]; this is because although researchers usually emphasize that changes in sexual orientation are unlikely, despite [[conversion therapy]] attempts, sexual identity can change over time. That sexual orientation is not always stable challenges the views of many within the LGBT community, who believe that sexual orientation is fixed and immutable.<ref name="Exploring">[http://www.advocate.com/health/love-and-sex/2014/02/11/exploring-umbrella-bisexuality-and-fluidity "Exploring the Umbrella: Bisexuality and Fluidity"], Trudy Ring for ''The Advocate'', February 11, 2014</ref> 

There is some level of cultural debate regarding the question of how (and if) fluidity exists among men,<ref>[http://www.dailydot.com/opinion/mostly-straight-men-sexual-fluidity/ "Why men's sex lives are more complicated than you think"], Nico Lang for "The Daily Dot", Jan 30, 2015</ref> including questions regarding fluctuations in attractions and arousal in male bisexuals.<ref>[http://slog.thestranger.com/slog/archives/2011/08/16/9534403-case-closed-bisexual-men-exist "Case Closed: Bisexual Men Exist!"], Dan Savage for ''The Stranger'', Aug. 16, 2011</ref>

Sexual fluidity may overlap with the label ''abrosexual'', which has been used to refer to regular changes in one's sexuality.<ref>{{Cite web|date=2021-06-21|title=LGBTQ+ 101 - What does abrosexual mean?|url=https://www.gaytimes.co.uk/life/what-does-abrosexual-mean/|url-status=live|access-date=2021-09-22|website=[[Gay Times]]|language=en-GB}}</ref><ref>{{Citation|last=Francis|first=Shadeen|title=Sexual Fluidity Behind Culture|date=2020|url=https://doi.org/10.1007/978-3-030-36222-5_7|work=Cultural Differences and the Practice of Sexual Medicine: A Guide for Sexual Health Practitioners|pages=115–132|editor-last=Rowland|editor-first=David L.|series=Trends in Andrology and Sexual Medicine|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-030-36222-5_7|isbn=978-3-030-36222-5|s2cid=213379215|access-date=2021-09-22|editor2-last=Jannini|editor2-first=Emmanuele A.|editor2-link=Emmanuele A. Jannini}}</ref>

==See also==
*[[Bambi effect (slang)|Bambi effect]]
*[[Bi-curious]]
*[[Biology and sexual orientation]]
*[[Environment and sexual orientation]]
*[[List of people who identify as sexually fluid]]
*[[Pansexuality]]
*[[Questioning (sexuality and gender)]]
*[[Situational sexual behavior]]

==References==
{{reflist}}

{{Sex}}
{{Sexual identities}}
{{LGBT|state=collapsed|orientation=expanded}}
{{Sexual ethics}}

{{DEFAULTSORT:Sexual Orientation}}
[[Category:Interpersonal relationships]]
[[Category:Sexual orientation]]
[[Category:LGBT]]
[[Category:Bisexuality| ]]