View source for Gender identity

{{short description|Personal sense of one's own gender}}
{{redirects here|Gender identification|the process of determining the sex of a human|Sex assignment|the process of determining the sex of an individual animal|Sexing}}
{{pp-semi-indef}}
{{Use dmy dates|date=August 2022}}
'''Gender identity''' is the personal sense of one's own [[gender]].<ref name="MorrowMessinger">{{cite book | vauthors = Morrow DF | chapter = Sexual Orientation and Gender Identity Expression. | veditors = Morrow DF, Messinger L | title = Sexual orientation and gender expression in social work practice: working with gay, lesbian, bisexual, and transgender people | date = 2006 | publisher = Columbia University Press | location = New York | isbn = 978-0-231-50186-6 | pages = 3–17 (8) | quote = Gender identity refers to an individual's personal sense of identity as masculine or feminine, or some combination thereof. | chapter-url = https://books.google.com/books?id=irs3BAAAQBAJ&dq=978-0-231-50186-6&pg=PA8 | access-date = 19 December 2021 | archive-date = 19 December 2021 | archive-url = https://web.archive.org/web/20211219122137/https://books.google.com/books?id=irs3BAAAQBAJ&dq=978-0-231-50186-6&pg=PA8 | url-status = live }}</ref> Gender identity can correlate with a person's [[assigned sex]] or can differ from it. In most individuals, the various biological determinants of sex are congruent, and consistent with the individual's gender identity.<ref>{{cite journal | vauthors = Bhargava A, Arnold AP, Bangasser DA, Denton KM, Gupta A, Hilliard Krause LM, Mayer EA, McCarthy M, Miller WL, Raznahan A, Verma R | display-authors = 6 | title = Considering Sex as a Biological Variable in Basic and Clinical Studies: An Endocrine Society Scientific Statement | journal = Endocrine Reviews | volume = 42 | issue = 3 | pages = 219–258 | date = May 2021 | pmid = 33704446 | pmc = 8348944 | doi = 10.1210/endrev/bnaa034 }}</ref> [[Gender expression]] typically reflects a person's gender identity, but this is not always the case.<ref name="Summers">{{cite book| vauthors = Summers RW |url=https://books.google.com/books?id=5nF1DQAAQBAJ&pg=PA232|title=Social Psychology: How Other People Influence Our Thoughts and Actions [2 volumes]|date=2016|publisher=ABC-CLIO|isbn=9781610695923|page=232}}</ref><ref name="APA2015">{{cite journal | author = American Psychological Association | title = Guidelines for psychological practice with transgender and gender nonconforming people | journal = The American Psychologist | volume = 70 | issue = 9 | pages = 832–864 | date = December 2015 | pmid = 26653312 | doi = 10.1037/a0039906 | s2cid = 1751773 }}</ref> While a person may express behaviors, attitudes, and appearances consistent with a particular [[gender role]], such expression may not necessarily reflect their gender identity. The term ''gender identity'' was coined by psychiatry professor [[Robert J. Stoller]] in 1964 and popularized by psychologist [[John Money]].<ref>{{cite web|url=https://www.nbcnews.com/health/health-news/dr-john-money-pioneer-sexual-identity-dies-flna1c9439208|title=Dr. John Money, pioneer in sexual identity, dies|website=[[NBC News]]|date=9 July 2006 |access-date=16 January 2022|archive-date=16 January 2022|archive-url=https://web.archive.org/web/20220116101434/https://www.nbcnews.com/health/health-news/dr-john-money-pioneer-sexual-identity-dies-flna1c9439208|url-status=live}}</ref><ref>{{cite book | vauthors = Bevan TE |title=The psychobiology of transsexualism and transgenderism: a new view based on scientific evidence |date=2015 |location=Santa Barbara, California |publisher=Bloomsbury |isbn=978-1440831270 |page=40}}</ref><ref>{{cite journal | vauthors = Stoller RJ | title = The Hermaphroditic Identity of Hermaphrodites | journal = The Journal of Nervous and Mental Disease | volume = 139 | issue = 5 | pages = 453–457 | date = November 1964 | pmid = 14227492 | doi = 10.1097/00005053-196411000-00005 | s2cid = 22585295 }}</ref>

In most societies, there is a basic division between gender attributes associated with males and females, a [[gender binary]] to which most people adhere and which includes expectations of [[masculinity]] and [[femininity]] in all aspects of [[sex and gender]]: biological [[sex]], gender identity, gender expression and sexual orientation.<ref name="Carlson">{{cite book |vauthors=Martin GN, Carlson NR, Buskist W |chapter=Psychology and Neuroscience |title=Psychology: The Science of Behaviour |date=2009 |publisher=Pearson |location=Toronto, Canada |isbn=978-0-205-64524-4 |edition=4th |chapter-url=https://books.google.com/books?id=zyMbUZYnWh8C&dq=Psychology%3A+the+science+of+behaviour+2009&pg=PA140 |pages=140–141 |access-date=19 December 2021 |archive-date=19 December 2021 |archive-url=https://web.archive.org/web/20211219122137/https://books.google.com/books?id=zyMbUZYnWh8C&dq=Psychology:+the+science+of+behaviour+2009&pg=PA140 |url-status=live }}</ref><ref>{{cite book | vauthors = Eller JD |title=Culture and diversity in the United States: so many ways to be American |date=2015 |publisher=Routledge |location=Abingdon, Oxon |isbn=978-1-317-57578-8 | page = 137 | quote = most Western societies, including the United States, traditionally operate with a binary notion of sex/gender }}</ref><ref name="AmPsycholAssn-whatis">{{cite web|title=Sexual Orientation & Homosexuality|publisher=[[American Psychological Association]]|date=2020|access-date=February 6, 2020|url=https://www.apa.org/topics/lgbt/orientation|archive-date=February 16, 2019|archive-url=https://web.archive.org/web/20190216213126/https://www.apa.org/topics/lgbt/orientation|url-status=live}}</ref> Some people do not identify with some, or all, of the aspects of gender associated with their biological sex; some of those people are [[transgender]], [[Non-binary gender|non-binary, or genderqueer]]. Some societies have [[third gender]] categories.<ref>{{cite book | vauthors = MacKenzie GO |title=Transgender nation |date=1994 |location=Bowling Green, OH |publisher=Popular Press |isbn=978-0-87972-596-9 | page = 43 | quote = transvestites [who do not identify with the dress assigned to their sex] existed in almost all societies }}; {{cite book | vauthors = Zastrow C | title = Introduction to Social Work and Social Welfare: Empowering People | date = 2013 |isbn=978-1-285-54580-6 | page = 234 | quote = There are records of males and females crossing over throughout history and in virtually every culture. It is simply a naturally occurring part of all societies. (quoting the North Alabama Gender Center) }}</ref>

The 2012 book ''Introduction to Behavioral Science in Medicine'' says that with exceptions, "Gender identity develops surprisingly rapidly in the early childhood years, and in the majority of instances appears to become at least partially irreversible by the age of 3 or 4".<ref name=bukatko/><ref name=IntBehavSciMed/> The [[Endocrine Society]] has stated "Considerable scientific evidence has emerged demonstrating a durable biological element underlying gender identity. Individuals may make choices due to other factors in their lives, but there do not seem to be external forces that genuinely cause individuals to change gender identity."<ref name="endocrine-society-position" /> [[Social constructivists]] argue that gender identity, or [[Gender expression|the way it is expressed]], are [[Social construction of gender|socially constructed]], determined by cultural and social influences. Constructivism of this type is not necessarily incompatible with the existence of an innate gender identity, since it may be the expression of that gender that varies by culture.<ref>{{Cite web |title=Gender identity |url=https://www.britannica.com/topic/gender-identity |access-date=2022-10-13 |website=[[Encyclopædia Britannica]] |language=en |archive-date=12 October 2023 |archive-url=https://web.archive.org/web/20231012085044/https://www.britannica.com/topic/gender-identity |url-status=live }}</ref>

== Age of formation ==

There are several theories about how and when gender identity forms, and studying the subject is difficult because children's immature [[language acquisition]] requires researchers to make assumptions from indirect evidence.<ref name="Boles_2013">{{cite book |vauthors=Solomon K |title=Men in Transition: Theory and Therapy |date=11 November 2013 |publisher=Springer Science & Business Media |isbn=978-1-4684-4211-3 |pages=101–102 |url=https://books.google.com/books?id=xIDjBwAAQBAJ |access-date=10 January 2021 |language=en |quote=Gender identity is the individual's personal and private experience of his/her gender. |archive-date=3 February 2021 |archive-url=https://web.archive.org/web/20210203234347/https://books.google.com/books?id=xIDjBwAAQBAJ |url-status=live }}</ref> John Money suggested children might have awareness of and attach some significance to gender as early as 18 months to 2 years; Lawrence Kohlberg argued that gender identity does not form until age 3.<ref name="Boles_2013"/> It is widely agreed that core gender identity is firmly formed by age 3.<ref name="Boles_2013"/><ref name=bukatko>{{cite book| vauthors = Bukatko D, Daehler MW |url= https://archive.org/details/childdevelopment0000buka |title=Child Development: A Thematic Approach|date=2004|publisher=Houghton Mifflin |isbn=978-0-618-33338-7 |page=[https://archive.org/details/childdevelopment0000buka/page/495 495]|language=en|url-access=registration}}</ref><ref>A few authorities say it forms between ages 3 and 4 rather than precisely at age 3, e.g. {{cite book | vauthors = Bryjak GJ, Soraka MP | title = Sociology: Cultural Diversity in a Changing World | veditors = Hanson K | publisher = Allyn & Bacon | date = 1997 | pages = 209–45 }}</ref> At this point, children can make firm statements about their gender<ref name="Boles_2013"/><ref name="Newmann">{{cite book|vauthors=Newmann B|url=https://books.google.com/books?id=oTY_7osGmqUC|title=Development Through Life: A Psychosocial Approach|date=20 December 2012|publisher=Cengage Learning|isbn=978-1111344665|page=243|access-date=2 July 2015|archive-date=3 February 2021|archive-url=https://web.archive.org/web/20210203231201/https://books.google.com/books?id=oTY_7osGmqUC|url-status=live}}</ref> and tend to choose activities and toys which are considered appropriate for their gender<ref name="Boles_2013"/> (such as dolls and painting for girls, and tools and rough-housing for boys),<ref>Christopher Bates Doob, ''Social Inequality and Social Stratification in US Society''</ref> although they do not yet fully understand the implications of gender.<ref name="Newmann"/> After age three, it is extremely difficult to change gender identity.<ref name="IntBehavSciMed">{{cite book|vauthors=Hine FR, Carson RC, Maddox GL, Thompson Jr RJ, Williams RB|url=https://books.google.com/books?id=0UYyBwAAQBAJ&pg=PA106|title=Introduction to Behavioral Science in Medicine|date=2012|publisher=Springer Science & Business Media|isbn=978-1-4612-5452-2|page=106|language=en|access-date=8 January 2020|archive-date=1 July 2020|archive-url=https://web.archive.org/web/20200701002454/https://books.google.com/books?id=0UYyBwAAQBAJ&pg=PA106|url-status=live}}</ref>

Martin and Ruble conceptualize this process of development as three stages: (1) as toddlers and pre-schoolers, children learn about defined characteristics, which are socialized aspects of gender; (2) around the ages of five to seven years, identity is consolidated and becomes rigid; (3) after this "peak of rigidity", fluidity returns and socially defined gender roles relax somewhat.<ref>{{cite journal| vauthors = Martin C, Ruble D |year=2004|title=Children's Search for Gender Cues Cognitive Perspectives on Gender Development|journal=Current Directions in Psychological Science|volume=13|issue=2|pages=67–70|doi=10.1111/j.0963-7214.2004.00276.x|s2cid=33579865}}</ref> Barbara Newmann breaks it down into four parts: (1) understanding the concept of gender, (2) learning [[gender role]] standards and stereotypes, (3) identifying with parents, and (4) forming gender preference.<ref name="Newmann" />

According to the [[UNESCO|United Nations Educational, Scientific and Cultural Organization]] (UNESCO) comprehensive sexuality education should raise awareness of topics such as gender and gender identity.<ref>{{Cite book|url=http://unesdoc.unesco.org/images/0026/002607/260770e.pdf|title=International technical guidance on sexuality education: An evidence-informed approach|publisher=UNESCO|year=2018|isbn=978-92-3-100259-5|location=Paris|page=18|access-date=23 February 2018|archive-date=13 November 2018|archive-url=https://web.archive.org/web/20181113072101/http://unesdoc.unesco.org/images/0026/002607/260770e.pdf|url-status=live}}</ref>

==Factors influencing formation==

=== Nature versus nurture ===

Although the formation of gender identity is not completely understood, many factors have been suggested as influencing its development. In particular, the extent to which it is determined by nurture (social environmental factors) versus biological factors (which may include non-social environmental factors) is an ongoing debate in psychology, known as "[[nature versus nurture]]".<ref name="ZhongNan">{{cite journal | vauthors = Zhu YS, Cai LQ | title = Effects of male sex hormones on gender identity, sexual behavior, and cognitive function | journal = Zhong Nan da Xue Xue Bao. Yi Xue Ban = Journal of Central South University. Medical Sciences | volume = 31 | issue = 2 | pages = 149–61 | date = April 2006 | pmid = 16706106 }}</ref><ref name=":2">{{Citation |last=Bakker |first=Julie |title=Sex Differentiation: Organizing Effects of Sex Hormones |date=2014 |work=Gender Dysphoria and Disorders of Sex Development: Progress in Care and Knowledge |series=Focus on Sexuality Research |pages=3–23 |editor-last=Kreukels |editor-first=Baudewijntje P.C. |url=https://rdcu.be/dkOR1 |access-date=2024-10-21 |place=Boston, MA |publisher=Springer US |language=en |doi=10.1007/978-1-4614-7441-8_1 |isbn=978-1-4614-7441-8 |editor2-last=Steensma |editor2-first=Thomas D. |editor3-last=de Vries |editor3-first=Annelou L.C.}}</ref> There is increasing evidence that the brain is effected by the organizational role of hormones in utero, circulating sex hormones and the expression of certain genes.<ref name=":2" />

Social factors which may influence gender identity include ideas regarding gender roles conveyed by family, authority figures, mass media, and other influential people in a child's life.<ref name="Henslin">{{cite book| vauthors = Henslin JM |title=Essentials of Sociology|publisher=Taylor & Francis|year=2001|isbn=978-0-536-94185-5|pages=65–67, 240}}</ref>{{Clarification needed|date=October 2024}} The [[social learning theory]] posits that children furthermore develop their gender identity through observing and imitating gender-linked behaviors, and then being rewarded or punished for behaving that way, thus being shaped by the people surrounding them through trying to imitate and follow them.<ref name="myers">{{cite book | vauthors = Myers DG | date = 2008 | title = Psychology | location = New York | publisher = Worth }}</ref><ref name="Cognitive theories of early gender">{{cite journal | vauthors = Martin CL, Ruble DN, Szkrybalo J | title = Cognitive theories of early gender development | journal = Psychological Bulletin | volume = 128 | issue = 6 | pages = 903–933 | date = November 2002 | pmid = 12405137 | doi = 10.1037/0033-2909.128.6.903 | citeseerx = 10.1.1.460.3216 }}</ref> 

Large-scale [[Twin study|twin studies]] suggest that the development of both transgender and cisgender gender identities is due to genetic factors, with a small potential influence of unique environmental factors.<ref>{{cite journal |display-authors=6 |vauthors=Polderman TJ, Kreukels BP, Irwig MS, Beach L, Chan YM, Derks EM, Esteva I, Ehrenfeld J, Heijer MD, Posthuma D, Raynor L, Tishelman A, Davis LK |date=March 2018 |title=The Biological Contributions to Gender Identity and Gender Diversity: Bringing Data to the Table |journal=Behavior Genetics |volume=48 |issue=2 |pages=95–108 |doi=10.1007/s10519-018-9889-z |pmid=29460079 |hdl=1871.1/acbbef10-1339-495d-8cc6-0d3f02742596}}</ref>

[[John Money]] was instrumental in the early research of gender identity, though he used the term ''gender role''.<ref>{{cite book|vauthors=Zucker KJ|url=https://www.springer.com/gp/book/9781402043130|title=Ethics and Intersex|date=2006|publisher=Springer Netherlands|isbn=978-1-4020-4313-0|veditors=Sytsma SE|page=167|language=en|access-date=14 January 2020|archive-date=8 March 2021|archive-url=https://web.archive.org/web/20210308133040/https://www.springer.com/gp/book/9781402043130|url-status=live}}</ref> He disagreed with the previous school of thought that gender was determined solely by biology. He argued that infants are born a blank slate and a parent could be able to decide their babies' gender.<ref name=":1">{{cite web|title=NOVA {{!}} Transcripts {{!}} Sex: Unknown {{!}} PBS|url=https://www.pbs.org/wgbh/nova/transcripts/2813gender.html|access-date=7 December 2018|website=www.pbs.org|archive-date=11 October 2011|archive-url=https://web.archive.org/web/20111011043248/http://www.pbs.org/wgbh/nova/transcripts/2813gender.html|url-status=live}}</ref> In Money's opinion, if the parent confidently raised their child as the opposite sex from earlier than age two, the child would believe that they were born that sex and act accordingly.<ref name=":0">{{Cite book| vauthors = Colapinto J |title=[[As Nature Made Him: The Boy Who Was Raised as a Girl]]|date=2006|publisher=HarperCollins|isbn=978-0061120565|edition=1st Harper Perennial|location=New York|oclc=71012749|author-link=John Colapinto|pages=19–20}}</ref> Money believed that nurture could override nature.<ref name=":1" />

==== Case of David Reimer and contrasting case ====
{{POV section|talk=Archive_5#Non-neutral_paragraph|date=August 2021}}{{further|Nature versus nurture}}
A well-known example in the nature-versus-nurture debate is the case of [[David Reimer]], born in 1965, otherwise known as "John/Joan". As a baby, Reimer went through a faulty circumcision, losing his male genitalia. John Money advised Reimer's parents to raise him as a girl. Reimer underwent [[sex reassignment surgery]] at seventeen months and grew up as a girl, dressing in girl clothes and surrounded by girl toys. In the early 1970s, Money reported that Reimer's [[Sex assignment|sex reassignment]] to female was a success, influencing the academic consensus toward the nurture hypothesis, and for the following 30 years, it became standard medical practice to reassign [[intersex]] infants and male infants with [[micropenis]]es to female.<ref name="Nova">{{cite episode |year=2001 |title=Sex: Unknown |series=Nova |series-link=Nova (American TV series) |transcript=Transcript |transcript-url=https://www.pbs.org/wgbh/nova/transcripts/2813gender.html |network=PBS}}</ref>

After Reimer tried to commit suicide at age 13, he was told that he had been born with male genitalia. Reimer stopped seeing Money, and underwent surgery to remove his breasts and reconstruct his genitals.<ref>{{cite book |title=Abnormal Psychology |vauthors=Nolen-Hoeksema S |date=2014 |publisher=McGraw-Hill |isbn=978-1-308-21150-3 |edition=6 |page=368}}<!--|access-date=5 December 2014--></ref> In 1997, sexologist [[Milton Diamond]] published a follow-up, revealing that Reimer had rejected his female reassignment, and arguing against the blank slate hypothesis and infant sex reassignment in general.<ref>{{Cite journal |last1=Diamond |first1=Milton |last2=Sigmundson |first2=H. Keith |date=1 March 1997 |title=Sex Reassignment at Birth: Long-term Review and Clinical Implications |journal=Archives of Pediatrics & Adolescent Medicine |volume=151 |issue=3 |pages=298–304 |doi=10.1001/archpedi.1997.02170400084015 |pmid=9080940 }}</ref>

Diamond was a longtime opponent of Money's theories. Diamond had contributed to research involving pregnant rats that showed hormones played a major role in the behavior of different sexes.<ref name=":0" />{{Page needed|date=August 2021}} The researchers in the lab would inject the pregnant rat with testosterone, which would then find its way to the baby's bloodstream.<ref name=":1" /> The females that were born had genitalia that looked like male genitalia. The females in the litter also behaved like male rats and would even try to mount other female rats, proving that biology played a major role in animal behavior.<ref name=":0" />{{Page needed|date=August 2021}}

One criticism of the Reimer case is that Reimer lost his penis at the age of eight months and underwent sex reassignment surgery at seventeen months, which possibly meant that Reimer had already been influenced by his socialization as a boy. Bradley et al. (1998) report the contrasting case of a 26-year-old woman with XY chromosomes whose penis was lost and who underwent sex reassignment surgery between two and seven months of age (substantially earlier than Reimer), whose parents were also more committed to raising their child as a girl than Reimer's, and who remained a woman into adulthood. She reported that she had been somewhat tomboyish during childhood, enjoying stereotypically masculine childhood toys and interests, although her childhood friends were girls. While she was [[bisexual]], having had relationships with both men and women, she found women more sexually attractive and they featured more in her fantasies. Her job at the time of the study was a blue-collar occupation that was practiced almost exclusively by men.<ref>{{cite journal | vauthors = Bradley SJ, Oliver GD, Chernick AB, Zucker KJ | title = Experiment of nurture: ablatio penis at 2 months, sex reassignment at 7 months, and a psychosexual follow-up in young adulthood | journal = Pediatrics | volume = 102 | issue = 1 | pages = e9 | date = July 1998 | pmid = 9651461 | doi = 10.1542/peds.102.1.e9 | quote = The present case report is a long-term psychosexual follow-up on a second case of ablatio penis in a 46 XY male. | doi-access = free }}</ref> Griet Vandermassen argues that since these are the only two cases being documented in scientific literature, this makes it difficult to draw any firm conclusions from them about the origins of gender identity, particularly given the two cases reached different conclusions. However, Vandermassen also argued that transgender people support the idea of gender identity as being biologically rooted, as they do not identify with their anatomical sex despite being raised and their behaviour reinforced according to their anatomical sex.<ref>{{cite book | vauthors = Vandermassen G |title=Who's Afraid of Charles Darwin?: Debating Feminism and Evolutionary Theory. |date=2005 |publisher=Rowman & Littlefield Publishers |location=Lanham |isbn=978-1-4616-4707-2 | pages = 112–113 }}</ref>

==== Other cases ====
One study by Reiner et al. looked at fourteen genetic males who had suffered [[cloacal exstrophy]] and were thus raised as girls. Six of them changed their gender identity to male, five remained female and three had ambiguous gender identities (though two of them had declared they were male). All the subjects had moderate to marked interests and attitudes consistent with that of biological males.<ref name="pmid14736925">{{cite journal | vauthors = Reiner WG, Gearhart JP | title = Discordant sexual identity in some genetic males with cloacal exstrophy assigned to female sex at birth | journal = The New England Journal of Medicine | volume = 350 | issue = 4 | pages = 333–41 | date = January 2004 | pmid = 14736925 | pmc = 1421517 | doi = 10.1056/NEJMoa022236 }}</ref> Another study,<ref>{{cite journal | vauthors = Meyer-Bahlburg HF | title = Gender identity outcome in female-raised 46, XY persons with penile agenesis, cloacal exstrophy of the bladder, or penile ablation. | journal = Archives of Sexual Behavior | date = August 2005 | volume = 34 | issue = 4 | pages = 423–438 | doi = 10.1007/s10508-005-4342-9 | pmid = 16010465 | s2cid = 34971769 }}</ref> using data from a variety of cases from the 1970s to the early 2000s (including Reiner et al.), looked at males raised as females due to a variety of developmental disorders ([[penile agenesis]], cloacal exstrophy or penile ablation). It found that 78% of those males raised as females were living as females.<ref name="pmid25667367">{{cite journal | vauthors = Saraswat A, Weinand JD, Safer JD | title = Evidence supporting the biologic nature of gender identity | journal = Endocrine Practice | volume = 21 | issue = 2 | pages = 199–204 | date = February 2015 | pmid = 25667367 | doi = 10.4158/EP14351.RA }}</ref> A minority of those raised as female later switched to male. However, none of the males raised as male switched their gender identity. Those still living as females still showed marked masculinisation of gender role behaviour and those old enough reported sexual attraction to women. The study's authors caution drawing any strong conclusions from it due to numerous methodological caveats which were a severe problem in studies of this nature. Rebelo et al. argue that the evidence in totality suggests that gender identity is neither determined entirely by childhood rearing nor entirely by biological factors.<ref name="pmid18287184">{{cite journal | vauthors = Rebelo E, Szabo CP, Pitcher G | title = Gender assignment surgery on children with disorders of sex development: a case report and discussion from South Africa | journal = Journal of Child Health Care | volume = 12 | issue = 1 | pages = 49–59 | date = March 2008 | pmid = 18287184 | doi = 10.1177/1367493507085618 | s2cid = 46058150 }}</ref>

===Biological factors===
Several prenatal biological factors, including genes and hormones, may affect gender identity.<ref name="ZhongNan"/><ref name="Ghosh">{{cite web|vauthors=Ghosh S|title=Gender Identity|url=http://emedicine.medscape.com/article/917990-overview|access-date=29 October 2012|publisher=MedScape|archive-date=6 March 2021|archive-url=https://web.archive.org/web/20210306211817/https://emedicine.medscape.com/article/917990-overview|url-status=live}}</ref> It has been suggested that gender identity is controlled by prenatal [[Sex hormone|sex steroids]], but this is hard to test because there is no way to study gender identity in animals.<ref>{{Cite book|vauthors=Balthazart J|url=https://books.google.com/books?id=3fjGjlcVINkC&q=the+biology+of+gender+identity|title=The Biology of Homosexuality|date=2012|publisher=Oxford University Press, USA|isbn=978-0-19-983882-0|page=5|language=en|author-link=Jacques Balthazart|access-date=18 September 2021|archive-date=17 February 2022|archive-url=https://web.archive.org/web/20220217115728/https://books.google.com/books?id=3fjGjlcVINkC&q=the+biology+of+gender+identity|url-status=live}}</ref> According to biologist [[Michael J Ryan (biologist)|Michael J. Ryan]], gender identity is exclusive to humans.<ref>{{Cite book|vauthors=Ryan MJ|url=https://books.google.com/books?id=-mUxDwAAQBAJ&q=Only+humans+have+gender+identity&pg=PA9|title=A Taste for the Beautiful: The Evolution of Attraction|date=16 January 2018|publisher=Princeton University Press|isbn=978-1-4008-8915-0|page=9|language=en|access-date=18 September 2021|archive-date=11 March 2022|archive-url=https://web.archive.org/web/20220311164835/https://books.google.com/books?id=-mUxDwAAQBAJ&q=Only+humans+have+gender+identity&pg=PA9|url-status=live}}</ref>

In a position statement, the [[Endocrine Society]] stated:<ref name="endocrine-society-position">{{Cite web |date=December 16, 2020 |title=Transgender Health |url=https://www.endocrine.org/advocacy/position-statements/transgender-health |access-date=2022-10-13 |website=www.endocrine.org |language=en |archive-date=10 October 2022 |archive-url=https://web.archive.org/web/20221010143844/https://www.endocrine.org/advocacy/position-statements/transgender-health |url-status=live }}</ref>

{{quote|The medical consensus in the late 20th century was that transgender and gender incongruent individuals suffered a mental health disorder termed "gender identity disorder." Gender identity was considered malleable and subject to external influences. Today, however, this attitude is no longer considered valid. Considerable scientific evidence has emerged demonstrating a durable biological element underlying gender identity. Individuals may make choices due to other factors in their lives, but there do not seem to be external forces that genuinely cause individuals to change gender identity.}}

====Transgender and transsexuality====
{{anchor|Biological causes of transgender and transsexuality}}
{{See also|Causes of transsexuality}}

Some studies have investigated whether there is a link between biological variables and [[transgender]] or [[transsexual]] identity.<ref>{{cite journal | vauthors = Vilain E | title = Genetics of intersexuality. | journal = Journal of Gay & Lesbian Psychotherapy | date = July 2006 | volume = 10 | issue = 2 | pages = 9–26 | doi = 10.1300/J236v10n02_02 | s2cid = 142998821 }}</ref><ref name="pmid15617542">{{cite journal | vauthors = Fleming A, Vilain E | title = The endless quest for sex determination genes | journal = Clinical Genetics | volume = 67 | issue = 1 | pages = 15–25 | date = January 2005 | pmid = 15617542 | doi = 10.1111/j.1399-0004.2004.00376.x | s2cid = 7595544 }}</ref><ref>{{cite journal | vauthors = Savic I, Arver S | title = Sex dimorphism of the brain in male-to-female transsexuals | journal = Cerebral Cortex | volume = 21 | issue = 11 | pages = 2525–2533 | date = November 2011 | pmid = 21467211 | doi = 10.1093/cercor/bhr032 | doi-access = free }} Concluded that gynephilic trans women had brains like men's, but in a few areas, trans women's brains were different from both men's and women's brains.</ref> Several studies have shown that [[Sexual dimorphism|sexually dimorphic]] brain structures in transsexuals are shifted away from what is associated with their birth sex and towards what is associated with their preferred sex.<ref>{{cite journal | vauthors = Gizewski ER, Krause E, Schlamann M, Happich F, Ladd ME, Forsting M, Senf W | title = Specific cerebral activation due to visual erotic stimuli in male-to-female transsexuals compared with male and female controls: an fMRI study | journal = The Journal of Sexual Medicine | volume = 6 | issue = 2 | pages = 440–448 | date = February 2009 | pmid = 18761592 | doi = 10.1111/j.1743-6109.2008.00981.x }} Found that a sample of androphilic trans women was shifted towards the female direction in brain responses.</ref><ref>{{cite journal | vauthors = Rametti G, Carrillo B, Gómez-Gil E, Junque C, Segovia S, Gomez Á, Guillamon A | title = White matter microstructure in female to male transsexuals before cross-sex hormonal treatment. A diffusion tensor imaging study | journal = Journal of Psychiatric Research | volume = 45 | issue = 2 | pages = 199–204 | date = February 2011 | pmid = 20562024 | doi = 10.1016/j.jpsychires.2010.05.006 }} Found that the white matter pattern in gynephilic trans men was shifted in the direction of biological males even before the female-to-male transsexuals started taking male hormones.</ref> The volume of the central subdivision of the [[stria terminalis#Bed nucleus of the stria terminalis|bed nucleus of a stria terminalis]] or BSTc (a constituent of the [[basal ganglia]] of the brain which is affected by [[Prenatal androgen transfer|prenatal androgens]]) of transsexual women has been suggested to be similar to women's and unlike men's,<ref>{{cite book | vauthors = Carlsson NR |title=Psychology: The Science of Behavior |date=2010 |publisher=Allyn & Bacon |location=Boston |isbn=978-0-205-54786-9 |edition=7th | page =418 }}</ref><ref>{{cite journal | vauthors = Zhou JN, Hofman MA, Gooren LJ, Swaab DF | title = A sex difference in the human brain and its relation to transsexuality | journal = Nature | volume = 378 | issue = 6552 | pages = 68–70 | date = November 1995 | pmid = 7477289 | doi = 10.1038/378068a0 | bibcode = 1995Natur.378...68Z | hdl-access = free | type = Submitted manuscript | s2cid = 4344570 | hdl = 20.500.11755/9da6a0a1-f622-44f3-ac4f-fec297a7c6c2 | url = https://pure.knaw.nl/portal/en/publications/a-sex-difference-in-the-human-brain-and-its-relation-to-transsexuality(9da6a0a1-f622-44f3-ac4f-fec297a7c6c2).html | access-date = 6 September 2018 | archive-date = 29 August 2017 | archive-url = https://web.archive.org/web/20170829164452/https://pure.knaw.nl/portal/en/publications/a-sex-difference-in-the-human-brain-and-its-relation-to-transsexuality(9da6a0a1-f622-44f3-ac4f-fec297a7c6c2).html | url-status = live }}</ref> but the relationship between BSTc volume and gender identity is still unclear.<ref>{{cite journal | vauthors = Rosenthal SM | title = Approach to the patient: transgender youth: endocrine considerations | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 99 | issue = 12 | pages = 4379–4389 | date = December 2014 | pmid = 25140398 | doi = 10.1210/jc.2014-1919 | quote = the sexually dimorphic differentiation of the BSTc in humans is not present until puberty, in contrast to rats, where such differences in the BST occur in the early postnatal period and apparently require perinatal differences in T levels (44, 45). Given that many transgender adolescents experience significant gender dysphoria before puberty (and before sex differences in BSTc volume emerge), the relationship between BSTc volume and gender identity would appear to be unclear. | doi-access = free }}</ref> Similar [[Biology and sexual orientation#Studies of brain structure|brain structure differences]] have been noted between gay and heterosexual men, and between lesbian and heterosexual women.<ref name="LeVay 1991">{{cite journal | vauthors = LeVay S | title = A difference in hypothalamic structure between heterosexual and homosexual men | journal = Science | volume = 253 | issue = 5023 | pages = 1034–1037 | date = August 1991 | pmid = 1887219 | doi = 10.1126/science.1887219 | bibcode = 1991Sci...253.1034L | s2cid = 1674111 }}</ref><ref name="Byne 2001">{{cite journal | vauthors = Byne W, Tobet S, Mattiace LA, Lasco MS, Kemether E, Edgar MA, Morgello S, Buchsbaum MS, Jones LB | display-authors = 6 | title = The interstitial nuclei of the human anterior hypothalamus: an investigation of variation with sex, sexual orientation, and HIV status | journal = Hormones and Behavior | volume = 40 | issue = 2 | pages = 86–92 | date = September 2001 | pmid = 11534967 | doi = 10.1006/hbeh.2001.1680 | s2cid = 3175414 }}</ref> Transsexuality has a genetic component.<ref>{{cite book | last1= Klink | first1= Daniel | title= Gender Dysphoria and Disorders of Sex Development |date=2013 | chapter=Genetic Aspects of Gender Identity Development and Gender Dysphoria | series= Focus on Sexuality Research |pages=25–51 |chapter-url=https://rdcu.be/dkOSo |publisher=Springer| doi= 10.1007/978-1-4614-7441-8_2 | isbn= 978-1-4614-7440-1 }}</ref>

Research suggests that the same hormones that promote the differentiation of sex organs in utero also elicit puberty and influence the development of gender identity. Different amounts of these male or female sex hormones can result in behavior and external genitalia that do not match the norm of their sex assigned at birth, and in acting and looking like their identified gender.<ref name="Oswalt">{{cite web| vauthors = Oswalt A |title=Factors Influencing Gender Identity|url=http://www.sevencounties.org/poc/view_doc.php?type=doc&id=37697&cn=1272|url-status=dead|archive-url=https://web.archive.org/web/20101218130452/https://sevencounties.org/poc/view_doc.php?type=doc&id=37697&cn=1272|archive-date=18 December 2010|access-date=29 October 2012|publisher=Seven Countries Services, Inc.}}</ref>

===Social and environmental factors===

Social scientists tend to assume that gender identities arise from social factors.<ref name="Kiecolt">{{cite book|vauthors=Kiecolt KJ, Hughes M, Momplaisir H|title=Identities in Everyday Life|date=2019|publisher=Oxford University Press|isbn=978-0-1908-7306-6|veditors=Stets JE, Serpe RT|page=195|chapter=Gender Identity Among U.S. Adults|chapter-url=https://books.google.com/books?id=iCSQDwAAQBAJ&q=%22rooted+in+social+structure%22|access-date=7 June 2020|archive-date=3 February 2021|archive-url=https://web.archive.org/web/20210203231513/https://books.google.com/books?id=iCSQDwAAQBAJ&q=%22rooted+in+social+structure%22|url-status=live}}</ref> In 1955, John Money proposed that gender identity was malleable and determined by whether a child was raised as male or female in early childhood.<ref name="pmid13260820">{{cite journal | vauthors = Money J, Hampson JG, Hampson JL | title = An examination of some basic sexual concepts: the evidence of human hermaphroditism | journal = Bulletin of the Johns Hopkins Hospital | volume = 97 | issue = 4 | pages = 301–19 | date = October 1955 | pmid = 13260820 | url = https://books.google.com/books?id=7-IaAQAAMAAJ&pg=PA301 | access-date = 6 December 2022 | archive-date = 6 December 2022 | archive-url = https://web.archive.org/web/20221206034531/https://books.google.com/books?id=7-IaAQAAMAAJ&pg=PA301 | url-status = live }}</ref><ref name="GDDSD">{{cite book | vauthors = Kreukels BP, Steensma TD, de Vries AL |title=Gender dysphoria and disorders of sex development: progress in care and knowledge |date=2014 |publisher=Springer |location=New York |isbn=978-1-4614-7441-8}}</ref> Money's hypothesis has since been discredited,<ref name="GDDSD"/><ref>{{cite book | vauthors = Fausto-Sterling A |title=Sexing the body: gender politics and the construction of sexuality |date=2000 |publisher=Basic Books |location=New York, NY |isbn=978-0-465-07713-7 |edition=1st}}</ref> but scholars have continued to study the effect of social factors on gender identity formation.<ref name="GDDSD"/> In the 1960s and 1970s, factors such as the absence of a father, a mother's wish for a daughter, or parental reinforcement patterns were suggested as influences; more recent theories suggesting that parental [[psychopathology]] might partly influence gender identity formation have received only minimal empirical evidence,<ref name="GDDSD"/> with a 2004 article noting that "solid evidence for the importance of postnatal social factors is lacking."<ref name="pmid15724806">{{cite journal | vauthors = Swaab DF | title = Sexual differentiation of the human brain: relevance for gender identity, transsexualism and sexual orientation | journal = Gynecological Endocrinology | volume = 19 | issue = 6 | pages = 301–12 | date = December 2004 | pmid = 15724806 | doi = 10.1080/09513590400018231 | s2cid = 1410435 | quote = "...direct effects of testosterone on the developing fetal brain are of major importance for the development of male gender identity and male heterosexual orientation. Solid evidence for the importance of postnatal social factors is lacking." }}</ref> A 2008 study found that the parents of [[Gender dysphoria|gender-dysphoric]] children showed no signs of psychopathological issues aside from mild depression in the mothers.<ref name="pmid18981931">{{cite journal | vauthors = Wallien MS, Cohen-Kettenis PT | title = Psychosexual outcome of gender-dysphoric children | journal = Journal of the American Academy of Child and Adolescent Psychiatry | volume = 47 | issue = 12 | pages = 1413–23 | date = December 2008 | pmid = 18981931 | doi = 10.1097/CHI.0b013e31818956b9 }}</ref> It has also been suggested that the attitudes of the child's parents may affect the child's gender identity, although evidence is minimal.<ref name="pmid6488962">{{cite journal | vauthors = Weinraub M, Clemens LP, Sockloff A, Ethridge T, Gracely E, Myers B | title = The development of sex role stereotypes in the third year: relationships to gender labeling, gender identity, sex-typed toy preference, and family characteristics | journal = Child Development | volume = 55 | issue = 4 | pages = 1493–503 | date = August 1984 | pmid = 6488962 | doi = 10.2307/1130019| jstor = 1130019 | quote = Previous investigators have failed to observe a relationship between parental attitudes and children's early sex role acquisition... }}</ref>

====Parental establishment of gender roles====
Parents who do not support gender nonconformity are more likely to have children with firmer and stricter views on gender identity and gender roles.<ref name="Oswalt"/> Recent literature suggests a trend towards less well-defined gender roles and identities, as studies of the parental association ("coding") of toys as masculine, feminine, or neutral indicate that parents increasingly code kitchens and in some cases dolls as neutral rather than exclusively feminine.<ref name="Kane">{{cite book| vauthors = Spade J |url= https://archive.org/details/kaleidoscopeofge0000unse_c1n2/page/177 |title=The Kaleidoscope of Gender|date=2010|publisher=Sage|isbn=978-1-4129-7906-1|location=London|pages=[https://archive.org/details/kaleidoscopeofge0000unse_c1n2/page/177 177–84]}}</ref> However, Emily Kane found that many parents still showed negative responses to items, activities, or attributes that were considered feminine, such as domestic skills, nurturance, and empathy.<ref name=Kane /> Research has indicated that many parents attempt to define gender for their sons in a manner that distances the sons from femininity,<ref name=Kane /> with Kane stating that "the parental boundary maintenance work evident for sons represents a crucial obstacle limiting boys' options, separating boys from girls, devaluing activities marked as feminine for both boys and girls, and thus bolstering gender inequality and heteronormativity."<ref name=Kane />

Many parents form gendered expectations for their child before it is even born, after determining the child's sex through technology such as [[ultrasound]]. The child thus is born to a gender-specific name, games, and even ambitions.<ref name="Ghosh"/> Once the child's sex is determined, most children are raised to in accordance with it, fitting a male or female gender role defined partly by the parents.

When considering the parents' social class, lower-class families typically hold traditional gender roles, where the father works and the mother, who may only work out of financial necessity, still takes care of the household. However, middle-class "professional" couples typically negotiate the division of labor and hold an egalitarian ideology. These different views on gender can shape the child's understanding of gender as well as the child's development of gender.<ref name="Halpern">{{cite journal | vauthors = Halpern HP, Perry-Jenkins M | title = Parents' Gender Ideology and Gendered Behavior as Predictors of Children's Gender-Role Attitudes: A Longitudinal Exploration | journal = Sex Roles | volume = 74 | issue = 11 | pages = 527–542 | date = May 2016 | pmid = 27445431 | pmc = 4945126 | doi = 10.1007/s11199-015-0539-0 }}</ref>

A study conducted by Hillary Halpern<ref name="Halpern" /> demonstrated that parental gender behaviors, rather than beliefs, are better predictors of a child's attitude on gender. A mother's behavior was especially influential on a child's assumptions of the child's own gender. For example, mothers who practiced more traditional behaviors around their children resulted in the son displaying fewer stereotypes of male roles while the daughter displayed more stereotypes of female roles. No correlation was found between a father's behavior and his children's knowledge of stereotypes of their own gender. Fathers who held the belief of equality between the sexes had children, especially sons, who displayed fewer preconceptions of their opposite gender.

==Intersex people==
{{Main|Intersex}}
Estimates of the number of people who are [[intersex]] range from 0.018% to 1.7%, depending on which conditions are counted as intersex.<ref>{{cite journal | vauthors = Blackless M, Charuvastra A, Derryck A, Fausto-Sterling A, Lauzanne K, Lee E | title = How sexually dimorphic are we? Review and synthesis | journal = American Journal of Human Biology | volume = 12 | issue = 2 | pages = 151–166 | date = March 2000 | pmid = 11534012 | doi = 10.1002/(SICI)1520-6300(200003/04)12:2<151::AID-AJHB1>3.0.CO;2-F | s2cid = 453278 }}</ref><ref>{{cite journal | vauthors = Sax L | title = How common is intersex? a response to Anne Fausto-Sterling | journal = Journal of Sex Research | volume = 39 | issue = 3 | pages = 174–178 | date = August 2002 | pmid = 12476264 | doi = 10.1080/00224490209552139 | s2cid = 33795209 }}</ref> An intersex person is one possessing any of several variations in [[sex]] characteristics including [[chromosome]]s, [[gonad]]s, [[sex hormones]], or [[genital]]s that, according to the United Nations [[Office of the High Commissioner for Human Rights]], "do not fit typical binary notions of male or female bodies".<ref name="unfe-fact">{{cite web|author=<!--Staff writer(s); no by-line.-->|date=2015|title=Free & Equal Campaign Fact Sheet: Intersex|url=https://unfe.org/system/unfe-65-Intersex_Factsheet_ENGLISH.pdf|access-date=28 March 2016|publisher=United Nations [[Office of the High Commissioner for Human Rights]]|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304071043/https://unfe.org/system/unfe-65-Intersex_Factsheet_ENGLISH.pdf|url-status=live}}</ref> An intersex variation may complicate initial [[sex assignment]]<ref name="Mieszczak2009">{{cite journal | vauthors = Mieszczak J, Houk CP, Lee PA | title = Assignment of the sex of rearing in the neonate with a disorder of sex development | journal = Current Opinion in Pediatrics | volume = 21 | issue = 4 | pages = 541–547 | date = August 2009 | pmid = 19444113 | pmc = 4104182 | doi = 10.1097/mop.0b013e32832c6d2c }}</ref> and that assignment may not be consistent with the child's future gender identity.<ref name="coe">{{Citation|last1=Council of Europe|title=Human rights and intersex people, Issue Paper|date=April 2015|url=https://wcd.coe.int/ViewDoc.jsp?Ref=CommDH/IssuePaper(2015)1&Language=lanEnglish&Ver=original|last2=Commissioner for Human Rights|author1-link=Council of Europe|access-date=11 March 2022|archive-date=6 January 2016|archive-url=https://web.archive.org/web/20160106203349/https://wcd.coe.int/ViewDoc.jsp?Ref=CommDH%2FIssuePaper%282015%291&Language=lanEnglish&Ver=original|url-status=live}}</ref> Reinforcing sex assignments through surgical and hormonal means may violate the individual's [[Intersex human rights|rights]].<ref name="swissnek">{{Cite book|publisher =Swiss National Advisory Commission on Biomedical Ethics NEK-CNE|url=http://www.nek-cne.ch/fileadmin/nek-cne-dateien/Themen/Stellungnahmen/en/NEK_Intersexualitaet_En.pdf|title=On the management of differences of sex development. Ethical issues relating to "intersexuality".Opinion No. 20/2012|date=November 2012|location=Berne|access-date=6 October 2016|archive-url=https://web.archive.org/web/20150423213245/http://www.nek-cne.ch/fileadmin/nek-cne-dateien/Themen/Stellungnahmen/en/NEK_Intersexualitaet_En.pdf|archive-date=23 April 2015|url-status=dead}}</ref><ref name="who2015">{{Cite book|last=[[World Health Organization]]|title=Sexual health, human rights and the law|date=2015|publisher=World Health Organization|isbn=978-9241564984|location=Geneva}}</ref>

A 2005 study on the gender identity outcomes of female-raised [[46,XY]] persons with [[penile agenesis]], [[cloacal exstrophy]] of the bladder, or penile [[ablation]], found that 78% of the study subjects were living as female, as opposed to 22% who decided to initiate a sex change to male in line with their genetic sex.<ref>{{cite journal | vauthors = Meyer-Bahlburg HF | title = Gender identity outcome in female-raised 46,XY persons with penile agenesis, cloacal exstrophy of the bladder, or penile ablation | journal = Archives of Sexual Behavior | volume = 34 | issue = 4 | pages = 423–438 | date = August 2005 | pmid = 16010465 | doi = 10.1007/s10508-005-4342-9 | s2cid = 34971769 }}</ref> The study concludes: "The findings clearly indicate an increased risk of later patient-initiated gender re-assignment to male after female assignment in infancy or early childhood, but are nevertheless incompatible with the notion of a full determination of core gender identity by prenatal androgens."

A 2012 clinical review paper found that between 8.5% and 20% of people with intersex variations experienced [[gender dysphoria]].<ref name="furtado">{{cite journal | vauthors = Furtado PS, Moraes F, Lago R, Barros LO, Toralles MB, Barroso U | title = Gender dysphoria associated with disorders of sex development | journal = Nature Reviews. Urology | volume = 9 | issue = 11 | pages = 620–627 | date = November 2012 | pmid = 23045263 | doi = 10.1038/nrurol.2012.182 | s2cid = 22294512 }}</ref> Sociological research in Australia, a country with a third 'X' sex classification, shows that 19% of people born with atypical sex characteristics selected an "X" or "other" option, while 52% are women, 23% men, and 6% unsure. At birth, 52% of persons in the study were assigned female, and 41% were assigned male.<ref name="oiijones">{{cite web|date=3 February 2016|title=New publication "Intersex: Stories and Statistics from Australia"|url=https://oii.org.au/30313/intersex-stories-statistics-australia/|url-status=dead|archive-url=https://web.archive.org/web/20160829033933/https://oii.org.au/30313/intersex-stories-statistics-australia/|archive-date=29 August 2016|access-date=18 August 2016|website=[[Organisation Intersex International Australia]]}}</ref><ref name="jones2016">{{Cite book| vauthors = Jones T, Hart B, Carpenter M, Ansara G, Leonard W, Lucke J |url=http://oii.org.au/wp-content/uploads/key/Intersex-Stories-Statistics-Australia.pdf|title=Intersex: Stories and Statistics from Australia|date=2016|publisher=Open Book Publishers|isbn=978-1-78374-208-0|location=Cambridge, UK|access-date=2 February 2016|archive-url=https://web.archive.org/web/20160914152729/http://oii.org.au/wp-content/uploads/key/Intersex-Stories-Statistics-Australia.pdf|archive-date=14 September 2016|url-status=dead}}</ref>

A study by Reiner & Gearhart provides some insight into what can happen when genetically male children with cloacal exstrophy are sexually assigned female and raised as girls,<ref name="Rosario">{{cite web|vauthors=Rosario V|author-link=Vernon Rosario|title=Reiner & Gearhart's NEJM Study on Cloacal Exstrophy – Review by Vernon Rosario, M.D., Ph.D|url=http://www.isna.org/node/564|website=[[Intersex Society of North America]]|access-date=4 April 2011|archive-date=19 February 2013|archive-url=https://web.archive.org/web/20130219025939/http://www.isna.org/node/564|url-status=live}}</ref> according to an 'optimal gender policy' developed by [[John Money]]:<ref name="swissnek" /> in a sample of 14 children, follow-up between the ages of 5 and 12 showed that 8 of them identified as boys, and all of the subjects had at least moderately male-typical attitudes and interests,<ref name="Rosario" /> providing support for the argument that genetic variables affect gender identity and behavior independent of socialization.

==Gender variance and non-conformance==
{{Main|Gender variance|Transgender|Transsexual|Non-binary gender}}
{{See also|Cisgender}}
Gender identity can lead to [[societal security]] issues among individuals that do not fit on a binary scale.<ref>{{Cite journal| vauthors = Hoogensen G, Rottem SB |date=29 June 2016|title=Gender Identity and the Subject of Security|journal=Security Dialogue|language=en|volume=35|issue=2|pages=155–71|doi=10.1177/0967010604044974 |doi-access=free |s2cid=55600340 |s2cid-access=free }}</ref> As of 2022, only 23 states plus Washington D.C. currently have state laws that explicitly prohibit discrimination based on sexual orientation and gender identity. Moreover, only "53% of [the] LGBTQ population live in states prohibiting housing discrimination based on sexual orientation and gender identity", while "17% of [the] LGBTQ population lives in states explicitly interpreting existing prohibition on sex discrimination to include sexual orientation and/or gender identity".<ref>{{cite web | url=https://www.lgbtmap.org/equality-maps/non_discrimination_laws | website=Movement Advancement Project |title=Nondiscrimination Laws |url-status=live |archive-url=https://web.archive.org/web/20231227153852/https://www.lgbtmap.org/equality-maps/non_discrimination_laws |archive-date= Dec 27, 2023 }}</ref>
In some cases, a person's gender identity is inconsistent with their biological sex characteristics (genitals and [[secondary sex characteristics]]), resulting in individuals dressing and/or behaving in a way which is perceived by others as outside cultural gender norms. These gender expressions may be described as [[gender variant]], transgender, or genderqueer (or [[non-binary gender|non-binary]])<ref>{{Cite journal| vauthors = Besser M, Carr S, Cohen-Kettenis PT, Connolly P, De Sutter P, Diamond M, Di Ceglie D, Higashi Y, Jones L, Kruijver FP, Martin J | display-authors = 6 |year=2003|title=Atypical Gender Development – A Review|url=http://www.gires.org.uk/genderdev.php|url-status=dead|journal=International Journal of Transgenderism|volume=9|pages=29–44|doi=10.1300/J485v09n01_04|archive-url=https://web.archive.org/web/20081007055838/http://www.gires.org.uk/genderdev.php|archive-date=7 October 2008|access-date=28 September 2008 |s2cid=216148638}}</ref> (there is an emerging vocabulary for those who defy traditional gender identity),<ref>{{cite news|date=27 May 2011|title=Toronto couple defend move to keep baby's sex secret|work=BBC News|url=https://www.bbc.co.uk/news/world-us-canada-13581835|access-date=21 July 2018|archive-date=11 March 2018|archive-url=https://web.archive.org/web/20180311210348/http://www.bbc.co.uk/news/world-us-canada-13581835|url-status=live}}</ref> and people who have such expressions may experience [[#Gender dysphoria and gender identity disorder|gender dysphoria]] (traditionally called gender identity disorder or GID). Transgender individuals are often greatly affected by language and gender pronouns before, during, and after their [[Transitioning (transgender)|transition]].<ref>{{cite web|date=18 May 2016|title=Words Matter: Affirming Gender Identity Through Language|url=http://www.insightintodiversity.com/words-matter-affirming-gender-identity-through-language/|access-date=24 October 2016|archive-date=1 August 2017|archive-url=https://web.archive.org/web/20170801082447/http://www.insightintodiversity.com/words-matter-affirming-gender-identity-through-language/|url-status=live}}</ref><ref>{{cite journal | vauthors = Vance SR | title = The Importance of Getting the Name Right for Transgender and Other Gender Expansive Youth | journal = The Journal of Adolescent Health | volume = 63 | issue = 4 | pages = 379–380 | date = October 2018 | pmid = 30286897 | doi = 10.1016/j.jadohealth.2018.07.022 | s2cid = 52921901 }}</ref>

In recent decades it has become possible to provide [[sex reassignment surgery]]. Some people who experience gender dysphoria seek such medical intervention to have their physiological sex match their gender identity; others retain the genitalia they were born with (see [[transsexual]] for some of the possible reasons) but adopt a gender role that is consistent with their gender identity.<ref name="Maizes">{{cite book | vauthors = Maizes V |title=Integrative women's health |date=2015 |location=Oxford |publisher=Oxford University Press |isbn=978-0-19-021480-7 |edition=Second | page = 745 | quote = Many transgender people experience gender dysphoria{{snd}}distress that results from the discordance of biological sex and experienced gender (American Psychiatric Association, 2013). Treatment for gender dysphoria, considered to be highly effective, includes physical, medical, and/or surgical treatments [...] some [transgender people] may not choose to transition at all. }}</ref> Within recent years modern society has made strides towards the acknowledgement and destigmatization of those who identify as non-binary or a gender variant, with sex reassignment surgery expected to grow by an annual rate of about 11% from the years 2022 to 2030.<ref>{{cite web | url=https://www.grandviewresearch.com/industry-analysis/us-sex-reassignment-surgery-market | title=U.S. Sex Reassignment Surgery Market Report, 2022-2030 | access-date=4 December 2022 | archive-date=4 December 2022 | archive-url=https://web.archive.org/web/20221204004841/https://www.grandviewresearch.com/industry-analysis/us-sex-reassignment-surgery-market | url-status=live }}</ref> Although sex reassignment surgery is expected to become more popular, the surgery is still not destigmatized in a lot of countries, including the United States. Such stigmatization has been shown to have adverse health effects on LGBTQ+ individuals, especially during the COVID-19 pandemic.<ref>{{cite journal |last1=Wallach |first1=Sara |last2=Garner |first2=Alex |last3=Howell |first3=Sean |last4=Adamson |first4=Tyler |last5=Baral |first5=Stefan |last6=Beyrer |first6=Chris |title=Address Exacerbated Health Disparities and Risks to LGBTQ+ Individuals during COVID-19 |journal=Health and Human Rights |date=December 2020 |volume=22 |issue=2 |pages=313–316 |pmid=33390717 |pmc=7762918 }}</ref>

==History and definitions==

===Definitions===
The terms ''gender identity'' and ''core gender identity'' were first used with their current meaning—one's personal experience of one's own gender<ref name="MorrowMessinger"/><ref name="Boles_2013" />—sometime in the 1960s.<ref name="GID">"The term 'gender identity' was used in a press release, November 21, 1966, to announce the new clinic for transsexuals at The Johns Hopkins Hospital. It was disseminated in the media worldwide, and soon entered the vernacular. ... gender identity is your own sense or conviction of maleness or femaleness." {{cite journal | vauthors = Money J | title = The concept of gender identity disorder in childhood and adolescence after 39 years | journal = Journal of Sex & Marital Therapy | volume = 20 | issue = 3 | pages = 163–177 | year = 1994 | pmid = 7996589 | doi = 10.1080/00926239408403428 | author-link = John Money }}</ref><ref>{{cite book | vauthors = Unge RK |title=Handbook of the psychology of women and gender |date=2001 |publisher=Wiley |location=New York |isbn=978-0-471-65357-8 | page = 102 | quote = ''Gender identity'' was introduced into the professional lexicon by Hooker and Stoller almost simultaneously in the early 1960s (see Money, 1985). For example, Stoller (1964) used the slightly different term ''core gender identity''... }}</ref> To this day they are usually used in that sense,<ref name="Carlson"/> though a few scholars additionally use the term to refer to the [[sexual orientation]] and [[sexual identity]] categories ''[[gay]]'', ''[[lesbian]]'' and ''[[Bisexuality|bisexual]]''.<ref>{{cite book | vauthors = Brym RJ, Lie J, Roberts LW, Rytina S |title=Sociology: Your Compass for a New World |date=2012 |publisher=Nelson Education |location=Toronto |isbn=978-0-17-650386-4 |edition=4th Canadian}}</ref> Gender expression is distinct from gender identity in that gender expression is how one chooses to outwardly express their gender through one's "name, pronouns, clothing, hair style, behavior, voice or body features."<ref>{{cite web | url=https://myhealth.alberta.ca/Alberta/Pages/gender-ID-expression-LGBTQ.aspx | title=Gender, gender identity, and gender expression | access-date=4 December 2022 | archive-date=13 April 2021 | archive-url=https://web.archive.org/web/20210413152257/https://myhealth.alberta.ca/Alberta/Pages/gender-ID-expression-LGBTQ.aspx | url-status=live }}</ref> It is thus distinct from gender identity in that it is the external expression of gender but may not necessarily portray a person's gender identity and may vary "according to racial/ethnic background, socio-economic status and place of residence."<ref>{{cite journal |last1=White Hughto |first1=Jaclyn M. |last2=Reisner |first2=Sari L. |last3=Pachankis |first3=John E. |title=Transgender Stigma and Health: A Critical Review of Stigma Determinants, Mechanisms, and Interventions |journal=Social Science & Medicine |date=December 2015 |volume=147 |pages=222–231 |doi=10.1016/j.socscimed.2015.11.010 |pmid=26599625 |pmc=4689648 }}</ref>

===Early medical literature===
In late-19th-century medical literature, women who chose not to conform to their expected gender roles were called "inverts", and they were portrayed as having an interest in knowledge and learning, and a "dislike and sometimes incapacity for needlework".<ref name="Padawer">{{cite news |last1=Padawer |first1=Ruth |title=What's So Bad About a Boy Who Wants to Wear a Dress? |url=https://www.nytimes.com/2012/08/12/magazine/whats-so-bad-about-a-boy-who-wants-to-wear-a-dress.html |work=The New York Times |date=8 August 2012 |access-date=27 February 2017 |archive-date=25 October 2012 |archive-url=https://web.archive.org/web/20121025213240/http://www.nytimes.com/2012/08/12/magazine/whats-so-bad-about-a-boy-who-wants-to-wear-a-dress.html |url-status=live }}</ref> During the mid-1900s, doctors pushed for corrective therapy on such women and children, which meant that gender behaviors that were not part of the norm would be punished and changed.<ref name="Khan2016">{{cite web |last1=Khan |first1=Farah Naz |title=A History of Transgender Health Care |url=https://blogs.scientificamerican.com/guest-blog/a-history-of-transgender-health-care/ |work=[[Scientific American]] |date=16 November 2016 |access-date=16 December 2023 |archive-date=8 December 2023 |archive-url=https://web.archive.org/web/20231208003936/https://blogs.scientificamerican.com/guest-blog/a-history-of-transgender-health-care/ |url-status=live }}</ref><ref name="Standards of Care">{{cite journal |title=Liberating sex, knowing desire: ''scientia sexualis'' and epistemic turning points in the history of sexuality |last=Chiang |first=Howard H. |journal=[[History of the Human Sciences]] |volume=25 |issue=5| pages=42–69 |doi=10.1177/0952695110378947 |date=18 November 2010|pmid=21322413 |s2cid=26766140 }}</ref> The aim of this therapy was to push children back to their "correct" gender roles and thereby limit the number of children who became transgender.<ref name="Padawer" />

===Freud and Jung's views===
In 1905, [[Sigmund Freud]] presented his theory of [[psychosexual development]] in ''[[Three Essays on the Theory of Sexuality]]'', giving evidence that in the pregenital phase children do not distinguish between sexes, but assume both parents have the same genitalia and reproductive powers. On this basis, he argued that bisexuality was the original sexual orientation and that heterosexuality was resultant of repression during the [[phallic stage]], at which point gender identity became ascertainable.<ref name="Ruse1988">{{citation |last=Ruse |first=Michael |title=Homosexuality: A Philosophical Inquiry |year=1988 |publisher=Basil Blackwell |location=New York |isbn=0-631-15275-X}}</ref> According to Freud, during this stage, children developed an [[Oedipus complex]] where they had sexual fantasies for the parent ascribed the opposite gender and hatred for the parent ascribed the same gender, and this hatred transformed into (unconscious) transference and (conscious) identification with the hated parent who both exemplified a model to appease sexual impulses and threatened to castrate the child's power to appease sexual impulses.<ref name=myers/> In 1913, [[Carl Jung]] proposed the [[Electra complex]] as he both believed that bisexuality did not lie at the origin of psychic life, and that Freud did not give adequate description to the female child (Freud rejected this suggestion).<ref>{{cite book | vauthors = Freud S |year=1931|chapter=Female Sexuality|title=The Standard Edition of the Complete Psychological Works of Sigmund Freud|volume=21|page=229}}</ref>

===1950s and 1960s===
During the 1950s and '60s, psychologists began studying gender development in young children, partially in an effort to understand the origins of [[homosexuality]] (which was viewed as a [[mental disorder]] at the time). In 1958, the Gender Identity Research Project was established at the [[UCLA Medical Center]] for the study of [[intersex]] and transsexual individuals. Psychoanalyst [[Robert Stoller]] generalized many of the findings of the project in his book ''Sex and Gender: On the Development of Masculinity and Femininity'' (1968). He is also credited with introducing the term ''gender identity'' to the International Psychoanalytic Congress in [[Stockholm, Sweden]], in 1963.<ref>{{cite book | last1 = Parker | first1 = Richard Guy | last2 = Aggleton | first2 = Peter | title = Culture, Society and Sexuality: A Reader | publisher = [[Psychology Press]] | url = https://books.google.com/books?id=MlZbFt6421gC&pg=PA80 | page = 80 | date = 1999 | isbn = 9781857288117 | access-date = 18 December 2023 | archive-date = 22 February 2024 | archive-url = https://web.archive.org/web/20240222035325/https://books.google.com/books?id=MlZbFt6421gC&pg=PA80#v=onepage&q&f=false | url-status = live }}</ref> Behavioral psychologist [[John Money]] was also instrumental in the development of early theories of gender identity. His work at [[Johns Hopkins University|Johns Hopkins Medical School]]'s Gender Identity Clinic (established in 1965) popularized an [[interactionist]] theory of gender identity, suggesting that, up to a certain age, gender identity is relatively fluid and subject to constant negotiation. His book ''Man and Woman, Boy and Girl'' (1972) became widely used as a [[college textbook]], although many of Money's ideas have since been challenged.<ref>{{cite book| vauthors = Haraway D |title=Simians, Cyborgs, and Women: The Reinvention of Nature |publisher=[[Free Association Books]]|year=1991|isbn=978-0-415-90386-8|location=London|page=133|author-link=Donna Haraway}}</ref><ref>{{cite book | vauthors = Karkazis K | title = [[Fixing Sex|Fixing Sex: Intersex, Medical Authority, and Lived Experience]] | publisher = Duke University Press | date = November 2008 | isbn = 978-0-8223-4318-9 }}</ref>

===Butler's views===
In the late 1980s, gender studies scholar [[Judith Butler]] began lecturing regularly on the topic of gender identity, and in 1990, they published ''[[Gender Trouble|Gender Trouble: Feminism and the Subversion of Identity]]'', introducing the concept of [[gender performativity]].<ref>{{cite book| vauthors = Butler J |title=Gender Trouble: Feminism and the Subversion of Identity|publisher=Routledge|year=1990|isbn=978-0415389556|location=London|pages=front/backmatter|author-link=Judith Butler}}</ref> Butler argues that the traditional view of gender is limiting in that it adheres to the dominant societal constraints that label gender as binary. In scrutinizing gender, Butler introduces a nuanced perception in which they unite the concepts of performativity and gender.<ref>{{cite encyclopedia |title=Feminist Perspectives on Sex and Gender |encyclopedia=The [[Stanford Encyclopedia of Philosophy]] |year=2023 |last=Mikkola |first=Mari |publisher=[[Metaphysics Research Lab (Stanford University)]] |url=https://plato.stanford.edu/entries/feminism-gender/ |edition=Fall 2023 |access-date=17 December 2023 |archive-date=1 June 2022 |archive-url=https://web.archive.org/web/20220601002408/https://plato.stanford.edu/entries/feminism-gender/ |url-status=live }}</ref>

==Present views==
===Medical field===
[[Transgender]] people sometimes wish to undergo physical surgery to refashion their [[primary sexual characteristics]], secondary characteristics, or both, because they feel they will be more comfortable with different genitalia. This may involve removal of penis, testicles or breasts, or the fashioning of a penis, vagina or breasts.<ref>{{cite journal |last1=Tristani-Firouzi |first1=Bita |last2=Veith |first2=Jacob |last3=Simpson |first3=Andrew |last4=Hoerger |first4=Kelly |last5=Rivera |first5=Andy |last6=Agarwalb |first6=Cori A. |title=Preferences for and barriers to gender affirming surgeries in transgender and non-binary individuals |journal=[[International Journal of Transgender Health]] |date=12 August 2021 |volume=23 |issue=4 |pages=458–471 |doi=10.1080/26895269.2021.1926391 |pmid=36324882 |pmc=9621289 }}</ref> In the past, sex assignment surgery has been performed on infants who are born with ambiguous genitalia. However, current medical opinion is strongly against this procedure on infants, and recommends that the procedure be only conducted when medically necessary.<ref>{{cite journal |last1=Behrens |first1=Kevin G. |title=A principled ethical approach to intersex paediatric surgeries |journal=BMC Medical Ethics |date=December 2020 |volume=21 |issue=1 |pages=108 |doi=10.1186/s12910-020-00550-x |pmid=33121480 |pmc=7597036 |doi-access=free }}</ref> Today, [[gender-affirming surgery]] is performed on people who choose to [[Gender transitioning|transition]] so that their external sexual organs will match their gender identity.<ref>{{cite journal |last1=Diamond |first1=Milton |title=Sex and Gender are Different: Sexual Identity and Gender Identity are Different |journal=Clinical Child Psychology and Psychiatry |date=July 2002 |volume=7 |issue=3 |pages=320–334 |doi=10.1177/1359104502007003002 |s2cid=144721800 }}</ref>

In the United States, the [[Affordable Care Act]] provided that [[health insurance exchange]]s would have the ability to collect demographic information on gender identity and sexual identity through optional questions, to help policymakers better recognize the needs of the [[LGBTQ]] community.<ref>{{cite web|vauthors=Baker K|title=FAQ: Collecting Sexual Orientation and Gender Identity Data|date=16 October 2012 |url=http://www.americanprogress.org/issues/lgbt/report/2012/10/16/41620/faq-collecting-sexual-orientation-and-gender-identity-data/|access-date=29 October 2012|publisher=Center for American Progress|archive-date=25 October 2012|archive-url=https://web.archive.org/web/20121025223111/http://www.americanprogress.org/issues/lgbt/report/2012/10/16/41620/faq-collecting-sexual-orientation-and-gender-identity-data/|url-status=live}}</ref> In 2020, however, the [[First presidency of Donald Trump|Trump administration]] finalized a rule that "would remove nondiscrimination protections for LGBTQ people when it comes to health care and health insurance" in the Affordable Care Act and extends to "regulations pertaining to access to health insurance."<ref name="npr.org">{{cite web | url=https://www.npr.org/sections/health-shots/2020/06/12/868073068/transgender-health-protections-reversed-by-trump-administration | title=Transgender Health Protections Reversed by Trump Administration | website=NPR | date=12 June 2020 | last1=Simmons-Duffin | first1=Selena | access-date=4 December 2022 | archive-date=23 June 2020 | archive-url=https://web.archive.org/web/20200623172448/https://www.npr.org/sections/health-shots/2020/06/12/868073068/transgender-health-protections-reversed-by-trump-administration | url-status=live }}</ref> This rule "is one of the many rules and regulations put forward by the Trump administration that defines "sex discrimination" as only applying when someone faces discrimination for being male or female, and does not protect people from discrimination on the basis of sexual orientation or gender identity."<ref name="npr.org"/>

===Gender dysphoria and gender identity disorder===

{{main article|Gender dysphoria}}

[[Gender dysphoria]] (previously called "gender identity disorder" or GID in the [[Diagnostic and Statistical Manual of Mental Disorders]] or DSM) is the formal diagnosis of people who experience significant [[dysphoria]] (discontent) with the sex they were assigned at birth and/or the gender roles associated with that sex:<ref>{{cite web | title = Gender Identity Disorder | work = Psychology Today | date = 24 October 2005 | url = http://www.psychologytoday.com/conditions/gender-identity-disorder | access-date = 16 December 2010 | archive-date = 6 March 2021 | archive-url = https://web.archive.org/web/20210306161912/https://www.psychologytoday.com/intl/conditions/gender-dysphoria | url-status = live }}</ref><ref>{{cite web |date=6 March 2010 |title=Gender Dysphoria Organization Research and Education - About Gender Dysphoria |url=http://www.genderdysphoria.org/genderdysphoria_medical.html |access-date=13 May 2021 | archive-url= https://web.archive.org/web/20100306075726/http://www.genderdysphoria.org/genderdysphoria_medical.html|archive-date=6 March 2010}}</ref> "In gender identity disorder, there is discordance between the natal sex of one's external genitalia and the brain coding of one's gender as masculine or feminine."<ref name="GID" /> The DSM (302.85) has five criteria that must be met before a diagnosis of gender identity disorder can be made, and the disorder is further subdivided into specific diagnoses based on age, for example [[gender identity disorder in children]] (for children who experience gender dysphoria).

The concept of gender identity appeared in the third edition of the DSM, [[DSM-III]] (1980), in the form of two [[mental disorder|psychiatric diagnoses]] of gender dysphoria: gender identity disorder of childhood (GIDC), and transsexualism (for adolescents and adults). The 1987 revision of the manual, [[DSM-III-R]], added a third diagnosis: gender identity disorder of adolescence and adulthood, nontranssexual type. This latter diagnosis was removed in the subsequent revision, DSM-IV (1994), which also collapsed GIDC and transsexualism into a new diagnosis of gender identity disorder.<ref name="Historical Note">{{cite journal | vauthors = Zucker KJ, Spitzer RL | title = Was the gender identity disorder of childhood diagnosis introduced into DSM-III as a backdoor maneuver to replace homosexuality? A historical note | journal = Journal of Sex & Marital Therapy | volume = 31 | issue = 1 | pages = 31–42 | date = Jan–Feb 2005 | pmid = 15841704 | doi = 10.1080/00926230590475251 | s2cid = 22589255 }}</ref> In 2013, the [[DSM-5]] renamed the diagnosis ''gender dysphoria'' and revised its definition.<ref>{{cite web|vauthors=Parry W|date=4 June 2013|title=DSM-5 Reflects Shift In Perspective On Gender Identity|url=http://www.huffingtonpost.com/2013/06/04/gender-dysphoria-dsm-5_n_3385287.html|access-date=23 October 2015|website=The Huffington Post|archive-date=8 May 2016|archive-url=https://web.archive.org/web/20160508073004/http://www.huffingtonpost.com/2013/06/04/gender-dysphoria-dsm-5_n_3385287.html|url-status=live}}</ref>

The authors of a 2005 academic paper questioned the classification of gender identity problems as a [[mental disorder]], speculating that certain DSM revisions may have been made on a tit-for-tat basis when certain groups were pushing for the removal of homosexuality as a disorder. This remains controversial,<ref name="Historical Note"/> although the vast majority of today's mental health professionals follow and agree with the current DSM classifications. In recent years, however, there has been a "growing chorus of voices contesting the pathologization of transgender lives and the dominance of medical-scientific narratives about trans experience."<ref>{{cite book |doi=10.1093/OBO/9780199791231-0215 |chapter=Transgender Children |title=Childhood Studies |year=2019 |last1=Kennedy |first1=RM |last2=Farley |first2=Lisa |isbn=978-0-19-979123-1 }}</ref> As such, in 2019, the [[World Health Organization]] removed gender dysphoria from the mental illness chapter and moved it instead to the sexual health chapter, changing the term "Gender Dysphoria" to "Gender Incongruence," thereby removing gender dysphoria as a pathological mental illness.<ref>{{cite web | url=https://icd.who.int/browse11/l-m/en#/http%3a%2f%2fid.who.int%2ficd%2fentity%2f90875286 | title=ICD-11 for Mortality and Morbidity Statistics | access-date=4 December 2022 | archive-date=1 August 2018 | archive-url=https://archive.today/20180801205234/https://icd.who.int/browse11/l-m/en%23/http://id.who.int/icd/entity/294762853#/http%3a%2f%2fid.who.int%2ficd%2fentity%2f90875286 | url-status=live }}</ref>

===International human rights law===
[[The Yogyakarta Principles]], a document on the application of [[international human rights law]], provide in the preamble a definition of gender identity as each person's deeply felt internal and individual [[experience]] of gender, which may not correspond with the sex assigned at birth, including the person's sense of the body (which may involve, if freely chosen, modification of bodily appearance or function by medical, surgical or other means) and other experience of gender, including dress, speech and mannerism. Principle 3 states that "Each person's self-defined [...] gender identity is integral to their personality and is one of the most basic aspects of self-determination, dignity and freedom. No one shall be forced to undergo medical procedures, including sex reassignment surgery, sterilisation or hormonal therapy, as a requirement for legal recognition of their gender identity."<ref>[[The Yogyakarta Principles]], ''Principle 3. The Right to recognition before the law''</ref> Principle 18 states that "Notwithstanding any classifications to the contrary, a person's sexual orientation and gender identity are not, in and of themselves, medical conditions and are not to be treated, cured or suppressed."<ref>The Yogyakarta Principles, ''Principle 18. Protection from medical abuse''</ref> Relating to this principle, the "Jurisprudential Annotations to the Yogyakarta Principles" observed that "Gender identity differing from that assigned at birth, or socially rejected [[gender expression]], have been treated as a form of [[mental illness]]. The pathologization of difference has led to gender-transgressive children and adolescents being confined in psychiatric institutions, and subjected to aversion techniques – including [[electroshock therapy]] – as a 'cure'."<ref>{{cite web | vauthors = O'Flaherty M, Williams G | title = Jurisprudential Annotations to the Yogyakarta Principles. | publisher = University of Nottingham. | work = Human Rights Law Centre | date = 2007 | page = 43 | url = http://www.yogyakartaprinciples.org/yogyakarta-principles-jurisprudential-annotations.pdf | archive-url = https://web.archive.org/web/20101122035344/http://www.yogyakartaprinciples.org/yogyakarta-principles-jurisprudential-annotations.pdf | archive-date = 22 November 2010 }}</ref> The "Yogyakarta Principles in Action" says "it is important to note that while 'sexual orientation' has been declassified as a mental illness in many countries, 'gender identity' or 'gender identity disorder' often remains in consideration."<ref>{{cite book | vauthors = Quinn S | title = An activist's guide to the yogyakarta principles on the application of international human rights law in relation to sexual orientation and gender identity. | publisher = Nicholson & Bass Limited | date = 2010 | url=http://www.ypinaction.org/wp/wp-content/uploads/2016/10/Activists_Guide_English_nov_14_2010.pdf |url-status=dead |archive-url= https://web.archive.org/web/20170104093608/http://www.ypinaction.org/wp/wp-content/uploads/2016/10/Activists_Guide_English_nov_14_2010.pdf |archive-date=4 January 2017 |access-date=14 February 2018 | page = 100 }}</ref> These Principles influenced the [[LGBT rights at the United Nations|UN declaration on sexual orientation and gender identity]]. In 2015, gender identity was part of the [[United States Supreme Court]] case ''[[Obergefell v. Hodges]]'' in which marriage was no longer legally restricted to be only between man and woman.<ref>{{cite court |litigants= Obergefell et al. V. Hodges, Director, Ohio Department of Health, et al. |court= U.S. Supreme Court |date= 26 June 2015 |url= https://www.supremecourt.gov/opinions/14pdf/14-556_3204.pdf }}</ref>

==Measurement==
No objective measurement or imaging of the human body exists for gender identity, as it is part of one's subjective experience.<ref>{{cite journal | vauthors = Dahlen S | title = De-sexing the Medical Record? An Examination of Sex Versus Gender Identity in the General Medical Council's Trans Healthcare Ethical Advice | journal = The New Bioethics | volume = 26 | issue = 1 | pages = 38–52 | date = March 2020 | pmid = 32011214 | doi = 10.1080/20502877.2020.1720429 | quote = No genetic marker, biochemical test, brain imaging, or objective measurement exists in medical practice for gender identity, which is itself of an unknown aetiology (NHS 2016, Bizic et al. 2018, Gerritse et al. 2018, Bewley et al. 2019). The central claim rests on a consistent declarative statement of the trans patient's subjective experience of self-hood. Therefore, we cannot prove or disprove a gender identity. Gender identity is a deeply held, spiritually significant, personal belief that can neither be confirmed nor rebutted by external evidence and biological data. | doi-access = free }}</ref><ref>{{cite journal | vauthors = Griffin L, Clyde K, Byng R, Bewley S | title = Sex, gender and gender identity: a re-evaluation of the evidence | journal = BJPsych Bulletin | volume = 45 | issue = 5 | pages = 291–299 | date = October 2021 | pmid = 32690121 | pmc = 8596152 | doi = 10.1192/bjb.2020.73 | quote = As a pure subjective experience, it may be overwhelming and powerful but is also unverifiable and unfalsifiable. | doi-access = free }}</ref> Numerous clinical measurements for assessing gender identity exist, including questionnaire-based, interview-based and task-based assessments. These have varying effect sizes among a number of specific sub-populations.<ref>{{cite journal | vauthors = Zucker KJ | title = Measurement of psychosexual differentiation | journal = Archives of Sexual Behavior | volume = 34 | issue = 4 | pages = 375–388 | date = August 2005 | pmid = 16010461 | doi = 10.1007/s10508-005-4336-7 | s2cid = 18953324 }}</ref> Gender identity measures have been applied in clinical assessment studies of people with [[gender dysphoria]] or [[intersex]] conditions.

==Terminology==
{{Further|Gender|Sex and gender distinction}}

Before the {{slink||1950s and 1960s}}, the term ''gender'' was [[Gender#As a grammatical category|used exclusively as a grammatical category]].<ref name="Udry-1994">{{cite journal |doi=10.2307/2061790 |first1=J. Richard |last1=Udry |date=November 1994 |title=The Nature of Gender |journal=Demography |volume=31 |issue=4 |pages=561–573 |jstor=2061790 |pmid=7890091 |doi-access=free }}</ref><ref name="Haig-2004">{{cite journal|first1=David |last1=Haig |author-link1=David Haig (biologist) |date=April 2004 |title=The Inexorable Rise of Gender and the Decline of Sex: Social Change in Academic Titles, 1945–2001 |journal=Archives of Sexual Behavior |volume=33 |issue=2 |pages=87–96 |pmid=15146141 |doi=10.1023/B:ASEB.0000014323.56281.0d |citeseerx=10.1.1.359.9143 |s2cid=7005542 }}</ref> The terms ''male'' and ''man'', or ''female'' and ''woman'', were used more or less interchangeably when referring to people of one sex or the other. As the term ''gender'' took on new meaning following the work of [[John Money]]<ref name="pmid13260820"/>{{additional citation needed|reason=This is the original coinage, but it doesn't verify the assertion about the evolution in the meaning afterward; a separate citation is needed for that.|date=July 2022}}, [[Robert Stoller]], and others, a [[Sex and gender distinction|distinction began to be drawn]] between the terms ''sex'' and ''gender''. As a result of the new understanding of gender, academic usage of the term ''sex'' began to be more restricted to biological aspects, and associated with the choices ''male'' and ''female'', while the term ''gender'' was associated initially with ''man'' or ''boy'', ''girl'' or ''woman''.<ref name="Haig-2004" />

===Binary gender identities===
{{Further|Man|Woman}}
{{expand section|find=gender identity|find2=binary man woman|small=no|date=July 2022}}

While academic usage of terms ''man'' and ''woman'' began to diverge at the same time, and become more restricted to concepts related to gender,<ref name="Haig-2004" /> this distinction was not universal (and still is not) even in academic usage, and even less so in more informal writing or in speech, which often conflate the two.<ref name="Stuhlsatz-2020">{{cite journal |last1=Stuhlsatz |first1=Molly A. M. |last2=Buck Bracey |first2=Zoë E. |last3=Donovan |first3=Brian M. |title=Investigating Conflation of Sex and Gender Language in Student Writing About Genetics |journal=Science & Education |date=December 2020 |volume=29 |issue=6 |pages=1567–1594 |doi=10.1007/s11191-020-00177-9 |bibcode=2020Sc&Ed..29.1567S |s2cid=229490367 |quote=<!--p.1587-->However, 40% of the students in the genetics of human sex condition and 16% in the genetics of plant sex condition used gender language in their responses. The patterns associated with students who use gender language in their responses in the genetics of plant or human sex conditions are indicative of conflation. ...<!--p.1589-->Conflation of biological sex and gender has been shown to engender unscientific essentialist beliefs about the nature of human difference that could manifest in sexism and transphobia.}}</ref><ref name="Hall-2021">{{cite journal |last1=Hall |first1=Jennifer |last2=Jao |first2=Limin |last3=Di Placido |first3=Cinzia |last4=Manikis |first4=Rebecca |date=July 2021 |title='Deep questions for a Saturday morning': An investigation of the Australian and Canadian general public's definitions of gender |journal=Social Science Quarterly |publisher=Wiley-Blackwell |volume=102 |issue=4 |pages=1866–1881 |doi=10.1111/ssqu.13021 |s2cid=238679176 |url=https://escholarship.mcgill.ca/concern/articles/db78th94f |quote=<!--p.1873-->The next most common response category pertained to responses in which participants simply provided the terms male and female, without any further description or explanation. Examples of such responses included: 'Gender would be male/female' (A2P45) and 'Male or female' (C3P48). ... <!--p.1874-->As shown, similar proportions of Australian and Canadian participants provided responses that were coded as Feelings/Identification or that were coded as Biology. The stark difference in response patterns by country pertained to responses that were coded as Male/Female: This was the modal category for the Australian participants, with nearly one‐third of participants providing such a response, whereas Male/Female was not even in the top three response categories for the Canadian participants. |access-date=13 January 2024 |archive-date=4 December 2023 |archive-url=https://web.archive.org/web/20231204141418/https://escholarship.mcgill.ca/concern/articles/db78th94f |url-status=live }}</ref>

===Non-binary gender identities===
{{See also|Gender binary|Non-binary gender|Third gender}}
Some people, and some societies, do not construct gender as a [[gender binary|binary]] in which everyone is either a boy or a girl, or a man or a woman. Those who exist outside the binary fall under the umbrella terms ''[[non-binary gender|non-binary]]'' or ''genderqueer''. Some cultures have specific gender roles that are distinct from "man" and "woman." These are often referred to as ''[[third gender]]s''.

====Fa'afafine====
{{Main|Fa'afafine}}
In [[Samoan culture]], or [[Fa'asamoa|Faʻa Samoa]], [[fa'afafine]] are considered to be a third gender. They are anatomically male but dress and behave in a manner considered typically feminine. According to Tamasailau Sua'ali'i (''see references''), fa'afafine in [[Samoa]] at least are often physiologically unable to reproduce. Fa'afafine are accepted as a natural gender, and neither looked down upon nor discriminated against.<ref>{{cite book | vauthors = Sua'ali'i T | chapter = [[Samoa]]ns and Gender: Some Reflections on Male, Female and Fa'afafine Gender Identities |title=Tangata o te moana nui: the evolving identities of Pacific peoples in Aotearoa /New Zealand |date=2001 |publisher=Dunmore Press |location=Palmerston North, N.Z. |isbn=978-0-86469-369-3}}</ref> Fa'afafine also reinforce their femininity with the fact that they are only attracted to and receive sexual attention from straight masculine men. They have been and generally still are initially identified in terms of labour preferences, as they perform typically feminine household tasks.<ref>{{cite journal| vauthors = Schmidt J |date=May 2003|title=Paradise Lost? Social Change and Fa'afafine in Samoa|journal=Current Sociology|volume=51|issue=3|pages=417–32|doi=10.1177/0011392103051003014|s2cid=145438114}}</ref> The [[Prime Minister of Samoa|Samoan Prime Minister]] is patron of the [[Samoa Fa'afafine Association]].<ref name="Stuff.co.nz_5233232">{{cite web|vauthors=Field M|date=5 July 2011|title=Transsexuals hailed by Samoan PM|url=http://www.stuff.co.nz/world/south-pacific/5233232/Transsexuals-hailed-by-Samoan-PM|access-date=1 October 2011|website=[[Stuff.co.nz]]|archive-date=10 October 2018|archive-url=https://web.archive.org/web/20181010060835/http://www.stuff.co.nz/world/south-pacific/5233232/Transsexuals-hailed-by-Samoan-PM|url-status=live}}</ref> Translated literally, fa'afafine means "in the manner of a woman."<ref name="pmid17951883">{{cite journal | vauthors = Vasey PL, Bartlett NH | title = What can the Samoan "Fa'afafine" teach us about the Western concept of gender identity disorder in childhood? | journal = Perspectives in Biology and Medicine | volume = 50 | issue = 4 | pages = 481–90 | date = 2007 | pmid = 17951883 | doi = 10.1353/pbm.2007.0056 | s2cid = 37437172 }}</ref>

====Hijras====
{{Main|Hijra (South Asia)}}

''Hijras'' are officially recognized as [[third gender]] in the Indian subcontinent,<ref>{{cite book |veditors=Shaw SM, Barbour NS, Duncan P, Freehling-Burton K, Nichols J |title=Women's Lives around the World: A Global Encyclopedia [4 volumes] |date=2017 |publisher=ABC-CLIO |isbn=978-1-61069-712-5 |url=https://books.google.com/books?id=jgRCDwAAQBAJ&pg=RA2-PA87 |access-date=19 December 2021 |archive-date=19 December 2021 |archive-url=https://web.archive.org/web/20211219135849/https://books.google.com/books?id=jgRCDwAAQBAJ&pg=RA2-PA87 |url-status=live }}</ref><ref>{{cite book |vauthors=Bevan TE |title=Being Transgender: What You Should Know |date=2016 |publisher=ABC-CLIO |isbn=9781440845253 |url=https://books.google.com/books?id=uMJHDQAAQBAJ&q=hijra%20third%20gender&pg=PA70 |page=70 |access-date=19 December 2021 |archive-date=19 December 2021 |archive-url=https://web.archive.org/web/20211219135853/https://books.google.com/books?id=uMJHDQAAQBAJ&q=hijra%20third%20gender&pg=PA70 |url-status=live }}</ref><ref>{{cite web|vauthors=Pasquesoone V|date=9 April 2014|url=http://mic.com/articles/87149/7-countries-giving-transgender-people-fundamental-rights-the-u-s-still-won-t|title=7 Countries Giving Transgender People Fundamental Rights the U.S. Still Won't|work=mic.com|access-date=17 June 2016|archive-date=3 March 2015|archive-url=https://archive.today/20150303002515/http://mic.com/articles/87149/7-countries-giving-transgender-people-fundamental-rights-the-u-s-still-won-t|url-status=live}}</ref><ref>{{cite web |url= http://pandeia.eu/region/inter/hijras-and-bangladesh-the-creation-of-a-third-gender/ |title=Hijras and Bangladesh: The creation of a third gender|date=2 December 2013|work=pandeia.eu|access-date=17 June 2016 |archive-url= https://web.archive.org/web/20160705033013/http://pandeia.eu/region/inter/hijras-and-bangladesh-the-creation-of-a-third-gender/ |archive-date=5 July 2016|url-status=dead}}</ref> being considered neither completely male nor female. Hijras have a recorded history in the Indian subcontinent since antiquity, as suggested by the [[Kama Sutra]]. Many hijras live in well-defined and organised all-hijra communities, led by a [[guru]].<ref>{{cite journal | vauthors = Nanda S | title = The hijras of India: cultural and individual dimensions of an institutionalized third gender role | journal = Journal of Homosexuality | volume = 11 | issue = 3–4 | pages = 35–54 | date = 1985 | pmid = 4093603 | doi = 10.1300/J082v11n03_03 | author-link = Serena Nanda | quote = The most significant relationship in the hijra community is that of the ''guru'' (master, teacher) and ''chela'' (disciple). }}</ref><ref>{{cite book |vauthors=Cohen L |veditors=Abramson PR, Pinkerton SD |title=Sexual Nature/Sexual Culture |date=1995 |publisher=University of Chicago Press |isbn=978-0-226-00182-1 |chapter-url=https://books.google.com/books?id=yl7gQ18B93cC |chapter=The Pleasures of Castration: the postoperative status of hijras, jankhas and academics |quote=Hijras are organized into households with a hijra guru as head, into territories delimiting where each household can dance and demand money from merchants |access-date=19 December 2021 |archive-date=19 December 2021 |archive-url=https://web.archive.org/web/20211219135854/https://books.google.com/books?id=yl7gQ18B93cC |url-status=live }}</ref> These communities have consisted over generations of those who are in abject poverty or who have been rejected by or fled their family of origin.<ref name = "Nanda_1999">{{cite book |vauthors=Nanda S |title=Neither Man Nor Woman: The Hijras of India |date=1999 |publisher=Wadsworth Publishing Company |isbn=978-0-534-50903-3 |url=https://books.google.com/books?id=K1sbAAAAYAAJ&q=0534509037 |page=116 |quote=None of the hijra narratives I recorded supports the widespread belief in India that hijras recruit their membership by making successful claims on intersex infants. Instead, it appears that most hijras join the community in their youth, either out of a desire to more fully express their feminine gender identity, under the pressure of poverty, because of ill-treatment by parents and peers for feminine behavior, after a period of homosexual prostitution or for a combination of these reasons. |access-date=19 December 2021 |archive-date=19 December 2021 |archive-url=https://web.archive.org/web/20211219135851/https://books.google.com/books?id=K1sbAAAAYAAJ&q=0534509037 |url-status=live }}</ref> Many work as [[prostitution|sex workers]] for survival.<ref name="Nanda_1996">{{cite book |vauthors=Nanda S |veditors=Herdt GH |title=Third sex, third gender: beyond sexual dimorphism in culture and history |date=1996 |publisher=Zone Books |isbn=978-0-942299-82-3 |chapter-url=https://books.google.com/books?id=dlI91F_FHSYC |chapter=Hijras: An Alternative Sex and Gender Role in India |access-date=19 December 2021 |archive-date=11 March 2022 |archive-url=https://web.archive.org/web/20220311164833/https://books.google.com/books?id=dlI91F_FHSYC |url-status=live }}</ref>

The word "hijra" is a [[Hindustani language|Hindustani]] word.<ref>{{cite book |vauthors=Reddy G |title=With Respect to Sex: Negotiating Hijra Identity in South India |date=2010 |publisher=University of Chicago Press |isbn=978-0-226-70754-9 |url=https://books.google.com/books?id=SyqTnL9jTFoC&q=Criminal%20Tribes%20Act&pg=PA26 |page=243 |quote=By and large, the Hindi/Urdu term ''hijra'' is used more often in the north of the country, whereas the Telugu term ''kojja'' is more specific to the state of Andhra Pradesh, of which Hyderabad is the capital. |access-date=19 December 2021 |archive-date=19 December 2021 |archive-url=https://web.archive.org/web/20211219135854/https://books.google.com/books?id=SyqTnL9jTFoC&q=Criminal%20Tribes%20Act&pg=PA26 |url-status=live }}</ref> It has traditionally been translated into English as "eunuch" or "[[hermaphrodite]]", where "the irregularity of the male genitalia is central to the definition".<ref name = "Nanda_1999" /> However, in general hijras are born male, only a few having been born with intersex variations.<ref>{{cite book |vauthors=Nanda S |veditors=Freilich M, Raybeck D, Savishinsky JS |title=Deviance: Anthropological Perspectives |date=1991 |publisher=Bergin & Garvey |isbn=978-0-89789-204-9 |chapter-url=https://books.google.com/books?id=Q0BE1WOXVD8C |chapter=chpt. 7. Deviant careers: the hijras of India |quote=Among thirty of my informants, only one appeared to have been born intersexed. |access-date=19 December 2021 |archive-date=19 December 2021 |archive-url=https://web.archive.org/web/20211219135850/https://books.google.com/books?id=Q0BE1WOXVD8C |url-status=live }}</ref> Some hijras undergo an initiation rite into the hijra community called nirvaan, which involves the [[Emasculation|removal of the penis, scrotum, and testicles]].<ref name="Nanda_1996" />

====Khanith====
{{Main|Khanith}}
The [[khanith]] form an accepted third gender in [[Oman]]. The khanith are [[male]] [[homosexual]] [[prostitute]]s whose dressing is male, featuring pastel colors (rather than white, worn by men), but their mannerisms are female. Khanith can mingle with women, and they often do at [[wedding]]s or other formal events. Khaniths have their own households, performing all tasks (both male and female). However, similar to men in their [[society]], khaniths can marry women, proving their [[masculinity]] by consummating the [[marriage]]. Should a [[divorce]] or death take place, these men can revert to their status as khaniths at the next wedding.<ref>{{cite book |url=https://archive.org/details/paradoxesofgende00lorb/page/94/mode/2up |title=Paradoxes of Gender |vauthors=Lorber J |date=1994 |publisher=Yale University Press |isbn=978-0-300-06497-1 |pages=94–95 |url-access=registration}}</ref>

====Two-spirit identities====
{{Main|Two-Spirit}}
<!--section needs slight expansion-->
Many [[Indigenous peoples of the Americas|indigenous North American Nations]] had more than two gender roles. Those who belong to the additional gender categories, beyond [[cisgender]] man and woman, are now often collectively termed "two-spirit" or "two-spirited". There are parts of the community that take "two-spirit" as a category over an identity itself, preferring to identify with culture or Nation-specific gender terms.<ref>{{Cite journal| vauthors = Hunt S |year=2016|title=An Introduction to the Health of Two-Spirit People: Historical, contemporary and emergent issues|url=http://www.nccah-ccnsa.ca/Publications/Lists/Publications/Attachments/156/2016-05-10-RPT-HealthTwoSpirit-Hunt-EN-Web.pdf|url-status=dead|journal=National Collaborative Centre Aboriginal Health|archive-url=https://web.archive.org/web/20170202004508/http://www.nccah-ccnsa.ca/Publications/Lists/Publications/Attachments/156/2016-05-10-RPT-HealthTwoSpirit-Hunt-EN-Web.pdf|archive-date=2 February 2017}}</ref>

== See also ==
* [[List of gender identities]]
* [[Social construction of gender]]
* [[Identity (social science)]]
* [[Sex and gender distinction]]
* [[Neuroscience of sex differences]]
* [[Queer heterosexuality]]
* [[Queer studies]]
* [[Queer theory]]

== References ==
{{reflist}}

== Further reading ==
* {{cite journal|doi=10.1111/jcc4.12081|title=Living the VirtuReal: Negotiating Transgender Identity in Cyberspace|journal=[[Journal of Computer-Mediated Communication]]|volume=19|issue=4|pages=824–838|year=2014| vauthors = Marciano A |doi-access=free}}

== External links ==
{{Library resources box|onlinebooks=yes}}
*{{Commons category inline}}
*[https://www.britannica.com/topic/gender-identity "Gender identity"] – ''[[Encyclopædia Britannica Online]]''
*''[http://documentarystorm.com/dr-money-and-the-boy-with-no-penis/ Dr. Money And The Boy With No Penis]''
*[http://www.ifge.org/ International Foundation for Gender Education]
*[http://transequality.org National Center for Transgender Equality]
*[https://web.archive.org/web/20110209002411/http://www.gpac.org/ Gender PAC] (archived 9 February 2011)
*[http://www.genderspectrum.org/ Gender Spectrum]
*[http://www.transgenderlawcenter.org/ Transgender Law Center]
*[https://web.archive.org/web/20080517084227/http://www.hrc.org/workplace/transgender Human Rights Campaign Foundation], Transgender Resources for the Workplace (archived 17 May 2008)
*[http://www.wpath.org/ World Professional Association for Transgender Health]
*[https://web.archive.org/web/20041209201347/http://www.genderology.org/ Genderology Directory Project], International listing of service providers for those affected by GID (archived 9 December 2004)
*[http://www.gires.org.uk/ Gender Identity Research and Education Society (GIRES)], British Charity encouraging and reporting on research into gender variance
*[http://www.ameliamarzec.com/genderanarchy/ Gender Anarchy Project]
*[https://web.archive.org/web/20120318004549/http://www.transfemmebutch.co.uk/forum.php TransFemmeButch] A forum and discussion board for trans men, femmes, and butches (archived 18 March 2012)
*[http://www.ohchr.org/Documents/Publications/BornFreeAndEqualLowRes.pdf Born Free and Equal – Sexual orientation and gender identity in international human rights law] ([[Office of the United Nations High Commissioner for Human Rights|OHCHR]])

{{LGBTQ}}
{{Transgender}}
{{Gender and sexual identities}}
{{Gender studies}}
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[[Category:Gender identity| ]]
[[Category:1960s neologisms]]
[[Category:LGBTQ]]