The hormonal theory of sexuality holds that, just as exposure to certain hormones plays a role in fetal sex differentiation, such exposure also influences the sexual orientation that emerges later in the individual. Prenatal hormones may be seen as the primary determinant of adult sexual orientation, or a co-factor.
Sex-typed behavior
The hormonal theory of sexuality holds that, just as exposure to certain hormones plays a role in fetal sex differentiation, such exposure also influences the sexual orientation that emerges later in the adult. Differences in brain structure that come about from chemical messengers and genes interacting on developing brain cells are believed to be the basis of sex differences in countless behaviors, including sexual orientation.[1]: 25 Prenatal factors that affect or interfere with the interaction of these hormones on the developing brain can influence later sex-typed behavior in children.[1]: 24 This hypothesis is originated from experimental studies in non-human mammals, yet the argument that similar effects can be seen in human neurobehavioral development is a much debated topic among scholars.[2] Recent studies, however, have provided evidence in support of prenatal androgen exposure influencing childhood sex-typed behavior.[2]
Fetal hormones may be seen as either the primary influence upon adult sexual orientation or as a co-factor interacting with genes.[3] Garcia-Falgueras and Dick Swaab disagree that social conditions influence sexual orientation to a large degree. As seen in young children as well as in vervet and rhesus monkeys, sexually differentiated behavior in toy preference is differing in males versus females, where females prefer dolls and males prefer toy balls and cars; these preferences can be seen as early as 3–8 months in humans.[2] It is impossible to completely rule out the social environment or the child's cognitive understanding of gender when discussing sex typed play in androgen-exposed girls.[2] Conversely, children tend towards objects which have been labelled for their own sex, or toys that they have seen members of their sex playing with previously.[2]
An endocrinology study by Garcia-Falgueras and Swaab postulated that "In humans, the main mechanism responsible of [sic] sexual identity and orientation involves a direct effect of testosterone on the developing brain."[1]: 25 Further, their study puts forward that intrauterine exposure to hormones is largely determinative. Sketching the argument briefly here, the authors say that sexual organs are differentiated first, and then the brain is sexually differentiated "under the influence, mainly, of sex hormones such as testosterone, estrogen and progesterone on the developing brain cells and under the presence of different genes as well ... The changes brought about in this stage are permanent. ... Sexual differentiation of the brain is not caused by hormones alone, even though they are very important for gender identity and sexual orientation."[1]: 24
Organizational aspects
Embryonic gonads develop primarily based on whether there is an SRY gene, normally present on the Y chromosome. If SRY exists, then the gonads develop as testes, and commence the production of androgen hormones, mainly testosterone, dihydrotestosterone (DHT) and androstenedione; production of testosterone and conversion into dihydrotestosterone during weeks 6 to 12 of pregnancy are key factors in the production of a male fetus's penis, scrotum and prostate.[4] In a female, on the other hand, absence of these levels of androgens results in development of typically female genitals.[4] Following this, sexual differentiation of the brain occurs; sex hormones exert organizational effects on the brain that will be activated in puberty.[4] As a result of these two processes occurring separately, the degree of genital masculinization does not necessarily relate to the masculinization of the brain.[1]: 24 [4] Sex differences in the brain have been found in many structures, most notably the hypothalamus and the amygdala.[2] However, few of these have been related to behavioral sex differences, and scientists are still working to establish firm links between early hormones, brain development and behavior.[2] The study of the organizational theory of prenatal hormones can be difficult, as ethically researchers cannot alter hormones in a developing fetus; instead, scholars must rely on naturally occurring abnormalities of development to provide answers.[5]
Most extensively studied in organizational effects of hormones is congenital adrenal hyperplasia (CAH).[6] CAH is a genetic disease that results in exposure to high levels of androgens beginning early in gestation. Girls with CAH are born with masculinized genitalia, which is corrected surgically as soon as possible.[5][6] CAH provides the opportunity for natural experiments, as people with CAH can be compared to people without it. However, "CAH is not a perfect experiment", since, "social responses to masculinized genitalia or factors related to the disease itself" can confound results.[5] Nonetheless several studies have shown that CAH has a clear but not determining influence on sexual orientation; women with CAH are less likely to be exclusively heterosexual than are other women.[6]
Since hormones alone do not determine sexual orientation and differentiation of the brain, the search for other factors that act upon sexual orientation have led genes such as the SRY and ZFY to be implicated.[7]
As of 2006 results from studies in humans had found conflicting evidence regarding the effect of prenatal exposure to hormones and psychosexual outcomes; Gooren noted in 2006 that studies in subprimate mammals are invalid measures of human sexual differentiation, as sex hormones follow a more "on-off" role in sex-typed behavior than is found in primates.[8]
Some studies do suggest that prenatal stress significantly increases the likelihood of homosexuality or bisexuality, although varying evidence exists for which trimester is most important.[1]: 24 Studies of endocrinology have found implications for amphetamines and thyroid-gland hormones to increase homosexuality in female offspring as well, although it has not been examined in conjunction with prenatal stress levels.[1]: 24
Some have postulated that postnatal (e.g., social and environmental factors) development can play a role in the sexual orientation of an individual, yet solid evidence of this has yet to be discovered. Children born through artificial insemination with donor sperm and consequently raised by lesbian couples have typically been heterosexually oriented.[1]: 24 [4] Summed up by Bao and Swaab, "The apparent impossibility of getting someone to change their sexual orientation ... is a major argument against the importance of the social environment in the emergence of homosexuality, as well as against the idea that homosexuality is a lifestyle choice."[4]
According to a multitude of studies over several decades, gay men have more older brothers on average, a phenomenon known as the fraternal birth order effect. It has been suggested that the greater the number of older male siblings the higher the level of androgen fetuses are exposed to. No evidence of birth order effects have been observed in women. The theory holds that the fraternal birth order effect is a result of a maternal immune response that is produced towards a factor of male development over several male pregnancies.[9] Bogaert's hypothesis argues that "the target of the immune response may be male specific molecules on the surface of male fetal brain cells (e.g., including those in the anterior hypothalamus). Anti-male antibodies might bind to these molecules and thus interfere with their role in normal sexual differentiation, leading some later born males to being attracted to men as opposed to women."[9] Garcia-Falgueras and Swaab state that "The ... fraternal birth order effect ... is putatively explained by an immunological response by the mother to a product of the Y chromosome of her sons. The chance of such an immune response to male factors would increase with every pregnancy resulting in the birth of a son."[1]: 24
Maternal antibodies against Y-chromosome neuroligin have been implicated in this effect,[10] among other evidence that favours this theory.[11] Further, while percentages of the likelihood of homosexuality have been estimated to be increased by 15[11]–48% per older brother, these odds really account for only a few percent of the population; thus, this hypothesis cannot be universally applied to the majority of homosexual men.[8] Most,[12] but not all, studies have been able to reproduce the fraternal birth order effect. Some did not find any statistically significant difference in either the sibling composition or rate of older brothers of gay and straight men,[13][14] including large, nationally representative studies in the US and Denmark.[15][16] However, Blanchard reanalyzed Frisch's 2006 Danish study and found the birth order effect was in-fact present.[17]
In conjunction with fraternal birth order, handedness provides further evidence of prenatal effects on sexual orientation, because handedness is regarded by many as a marker of early neurodevelopment. Other correlates to handedness (e.g., cerebral laterality, prenatal hormonal profiles, spatial ability) have been linked to sexual orientation, either empirically and/or theoretically.[9] In right-handed individuals, the number of older brothers increased the odds of homosexual orientation, but this effect was not seen in left-handed individuals.[9] As with other purported marks indicating higher incidence of homosexuality, however, the link with handedness remains ambiguous and several studies have been unable to replicate it.[18][19][20]
A gene of the Rh system has been discussed as a possible candidate for affecting fraternal birth order, as it has been linked to both handedness and immune system functioning.[9] Gene variants in the Rh system are implicated in a maternal response to what is known as hemolytic disease of the newborn. Rh is a factor in blood, and in cases where the mother is absent of this (Rh-) while carrying an Rh+ fetus, an immune response may develop with deleterious effects. The Rh gene hypothesis is a strong candidate because not only does it involve the maternal immune response, but it has been implicated in handedness as well.[9]
Variants of the androgen receptor (AR) gene have also been discussed, in that non-right-handedness in men has been linked with greater CAG repeats in the AR gene, which in turn is associated with lower testosterone. A theory that high prenatal testosterone leads to neuronal and axonal loss in the corpus callosum is supported by this hypothesis.[21]
There is evidence that mutations in NLGN4X and NLGN4Y are linked to autism spectrum conditions[22][23] and such conditions may be elevated in asexual people.[24] Thus, NLGN4X/Y may affect neurological functioning associated with, broadly, the forming of social connections to others, including sexual/romantic ones.
Prenatal Thyroid Theory of Homosexuality/Gender Dysphoria
Prenatal thyroid theory of same-sex attraction/gender dysphoria has been based on clinical and developmental observations of youngsters presenting to child psychiatry clinics in Istanbul/Turkey. The report of 12 cases with same-sex attraction/gender dysphoria born to mothers with thyroid diseases was first presented in EPA Congress, Vienna (2015) and published as an article in the same year.[25][26] The extremely significant relationship between the two conditions suggested an independent model, named as Prenatal Thyroid Model of Homosexuality. According to Turkish child & adolescent psychiatrist Osman Sabuncuoglu, who generated the theory, maternal thyroid dysfunction may lead to abnormal deviations from gender-specific development in the offspring. Autoimmune destructive process as seen in Hashimoto thyroiditis, diminished supply of thyroid hormones and impacts on prenatal androgen system were all considered as contributing mechanisms. In a follow-up theoretical paper,[27] previous research findings indicating higher rates of polycystic ovary syndrome (PCOS) in female-to-male transsexuals and lesbian women were conceived as an indication of Prenatal Thyroid Model since PCOS and autoimmune thyroiditis are frequently comorbid diseases. Likewise, increased rates of autism spectrum disorder in children born to mothers with thyroid dysfunction and overrepresentation of ASD individuals in gender dysphoria populations suggest such an association. A second group of young children with this pattern were presented in IACAPAP Congress, Prague (2018).[28] Furthermore, 9 additional cases were reported in IACAPAP Congress, Rio de Janeiro (Sabuncuoglu, 2024).[1]
The findings from previous research in LGBT populations had called for attention to be paid to thyroid system.[29][30] A commentary by Jeffrey Mullen, published shortly after the 2015 article, underlined the importance of Prenatal Thyroid Model and supported developments in this field.[31] Afterwards, several authors have emphasized the role of thyroid system in sexuality while citing the Prenatal Thyroid Model.[32][33][34][35] Among them, Carosa et al. concluded that thyroid hormones, affecting the human sexual function strongly, the thyroid gland must be considered, along with the genitals and the brain, a sexual organ.[32] As a tertiary source, an authoritative book on the subject of interplay between endocrinology, brain and behavior has also cited the thyroid-homosexuality proposal article in the latest edition.[36] Most importantly, a genome-wide genetic association study on male homosexuals identified a significant region on Chromosome 14 which is related to autoimmune thyroid dysfunction in human beings.[37] This is apparently a big support to the Prenatal Thyroid Model.
There is evidence of a correlation between sexual orientation and traits that are determined in utero.[3][page needed] A study by McFadden in 1998 found that auditory systems in the brain, another physical trait influenced by prenatal hormones is different in those of differing orientations; likewise the suprachiasmatic nucleus (SCN) was found by Swaab and Hofman to be larger in homosexual men than in heterosexual men.[38] The suprachiasmatic nucleus is also known to be larger in men than in women.[39] An analysis of the hypothalamus by Swaab and Hofman (1990;2007) found that the volume of the SCN in homosexual men was 1.7 times larger than a reference group of male subjects, and contained 2.1 times as many cells.[8][40] During development, the volume of the SCN and the cell counts reach peak value at approximately 13 to 16 months after birth; at this age, the SCN contains the same number of cells as was found in adult male homosexuals, yet in a reference group of heterosexual males the cell numbers begin to decline to the adult value of 35% of the peak value.[8] These results were replicated and confirmed the findings.[41] However; there also has yet to be a meaningful interpretation of these results provided in the context of human sexual orientation.[8] Some highly disputed studies suggest gay men have also been shown to have higher levels of circulating androgens[42][43][44] and larger penises,[45] on average, than heterosexual men.
In a 1991 study, Simon LeVay demonstrated that a tiny clump of neurons of the anterior hypothalamus—which is believed to control sexual behavior and linked to prenatal hormones—known as the interstitial nuclei of the anterior was, on average, more than twice the size in heterosexual men when contrasted to homosexual men. Due to this area also being nearly twice the size in heterosexual men than in heterosexual women, the implication is that the sexual differentiation of the hypothalamus in homosexuals is in a female direction.[8] In 2003 scientists at Oregon State University announced that they had replicated his findings in sheep.
Other evidence pointed to the contrary: the SCN of homosexual males has been demonstrated to be larger (both the volume and the number of neurons are twice as many as in heterosexual males), contradicting the hypothesis that homosexual males have a "female hypothalamus".[46][41] William Byne and colleagues also weighed and counted numbers of neurons in INAH3 tests not carried out by LeVay. The results for INAH3 weight were similar to those for INAH3 size; that is, the INAH3 weight for the heterosexual male brains was significantly larger than for the heterosexual female brains, while the results for the gay male group were between those of the other two groups but not quite significantly different from either.[47] Finally, the same research has found that the INAH3 is smaller in volume in homosexual men than in heterosexual men because homosexual men have a higher neuronal packing density in the INAH3 than heterosexual men; there is no difference in the number or cross-sectional area of neurons in the INAH3 of homosexual versus heterosexual men.[48]
Female homosexuality
Most empirical or theoretical research into women's sexual orientation has, historically, been guided by the idea of lesbians as essentially masculine and heterosexual women as essentially feminine.[49] Typically, this belief is traced to the early "inversion theory" of sex researchers who state that homosexuality is a result of biological abnormalities that "invert" sexual attraction and personality.[49] Handedness research has provided implications; because more men than women present a preference for their left hand, the higher proportion of non-right handedness that has been discovered among lesbians when compared to heterosexual women demonstrates a possible link of prenatal masculinization and sexual orientation.[49] Backing this up are reports that lesbians display more masculinized 2D;4D digit ratios than heterosexual women, based on data gathered from at least six different laboratories.[50] This effect has not yet been observed between homosexual and heterosexual males.[50] However, the validity of this measure of digit ratios remains controversial as a predictor of prenatal androgen, as many other prenatal factors may play roles in bone growth in prenatal stages of development.[8] While many studies have found results confirming this hypothesis, others have failed to replicate
these findings,[8] leaving the validity of this measure unconfirmed.
Diethylstilbestrol (DES), a drug that has been in the past prescribed to prevent miscarriages, has also been studied in relation to women's sexual orientation. It has been observed to exert a masculinizing/defeminizing effect on the developing brain of the fetus.[49] When compared to controls, higher percentages of DES-exposed women (17% vs 0%) reported that they had engaged in same-sex relations; however, the great majority of DES women stated an exclusively heterosexual orientation.[49]
Girls with congenital adrenal hyperplasia (an autosomal recessive condition which results in high androgen levels during fetal development) have more masculinized sex role identities and are more likely to have a homosexual sexual orientation as adults than controls.[51][52][53][54][55] An alternative explanation for this effect is the fact that girls with this condition are born with masculinized external genitalia, which leads their parents to raise them in a more masculine manner, thus influencing their sexual orientation as adults. However, the degree to which the girls' genitals are masculinized does not correlate with their sexual orientation, suggesting that prenatal hormones are a stronger causal factor, not parental influence.
Together with congenital adrenal hyperplasia, DES studies have provided little support of the prenatal hormone theory of sexual orientation; they do, however, provide the framework for possible pathways to a homosexual orientation for a small number of women.[49]
In individuals with gender dysphoria, previously known as gender identity disorder (GID), prenatal exposure to testosterone has been hypothesized to have an effect on gender identity differentiation. The 2D;4D finger ratio, or relative lengths of the 2nd "index" and 4th "ring" fingers, has become a popular measure of prenatal androgen because of accumulated evidence suggesting the 2D;4D ratios are related to prenatal exposure to testosterone.[56] Many children with gender dysphoria differentiate a homosexual orientation during adolescence, but not all of them; adults with "early onset", or a childhood history of cross-gender behavior, often have a homosexual orientation. Adults with "late onset", or those without a childhood history of said behavior, are more likely to have a non-homosexual orientation.[56]
Prenatal androgen exposure has been associated with an increased chance of patient-initiated gender reassignment to male after being initially raised as female in early childhood or infancy.[8][57] Gooren found that organizational effects of prenatal androgens are more prevalent in gender role behavior than in gender identity, and that there are preliminary findings that suggest evidence of a male gender identity being more frequent in patients with fully male-typical prenatal androgenization.[8]
Individuals with complete androgen insensitivity syndrome are almost always brought up as females, and the differentiation of gender identity/role is feminine.[8] This example is important in demonstrating that chromosomes and gonads alone do not dictate gender identity and role.[8]
Because organ differentiation and brain differentiation occur at different times, in rare cases transsexualism can result.[1]: 24
Drawing on some transsexualism cases, Garcia-Falgueras and Swaab state that "[f]rom these examples it appears that the direct action of testosterone on the developing brain in boys and the lack of such action on the developing brain in girls are crucial factors in the development of male and female gender identity and sexual orientation".[1]: 26 Countless studies have been run on peripheral levels of sex steroids in male and female homosexuals, a considerable number of which claimed to find "less 'male hormone' and/or more 'female hormone' in male homosexuals and vice versa in female homosexuals".[8] However, these findings have been reviewed and have subsequently been dismissed by Gooren as suffering from faulty design and interpretation.[8]
Factors implicated in the development of transsexuality include chromosomal abnormalities, polymorphisms of certain genes, and variations in aromatase (cytochrome P450 CYP19) and CYP17.[8] Girls with congenital adrenal hyperplasia show an increase in probability of transsexuality later in life; however, this probability is still only 1–3% in CAH.[8] Although historically abnormal sexual differentiation has pointed to androgens as a causal factor, there are codeterminants of gender identity and sexual orientation.[8] These factors are currently unknown, and thus no clear cut answer for the cause of transsexualism and homosexuality exists.[8]
Due to relatively small population sizes, generalizability of studies on transsexuality cannot be assumed.
Endocrine disruptors
Endocrine disrupting chemicals (EDCs) are chemicals that, at certain doses, can interfere with the endocrine system in mammals.[58] Work on possible neurotoxic effects of endocrine disruptors, and their possible effects on sexual orientation when a fetus is exposed to them, is in its infancy: "we mostly know about the relationship between EDC exposure and neurobehavioral function through an examination of outcomes within a limited sphere of questions."[59][better source needed] While studies have found that xenoestrogens and xenoandrogens can alter the brain's sexual differentiation in a number of species used as animal models,[60][better source needed] from the data in hand to date, it is "misleading ...to expect EDCs to produce profiles of effects, such as sexually dimorphic behaviors, as literal copies of those produced by native hormones. Such agents are not hormones. They should not be expected to act precisely as hormones."[59][better source needed]
^ abcdefghijkGarcia-Falgueras A, Swaab DF (2010). "Sexual hormones and the brain: an essential alliance for sexual identity and sexual orientation". Pediatric Neuroendocrinology. Endocrine Development. Vol. 17. pp. 22–35. doi:10.1159/000262525. ISBN978-3-8055-9302-1. PMID19955753.
^ abWilson, G., & Q. Rahman, Born Gay: The Psychobiology of Human Sex Orientation, Peter Owen Publishers; 2nd edition (May 1, 2008) ISBN9780720613094
^ abcdefBao AM, Swaab DF (April 2011). "Sexual differentiation of the human brain: relation to gender identity, sexual orientation and neuropsychiatric disorders". Frontiers in Neuroendocrinology. 32 (2): 214–226. doi:10.1016/j.yfrne.2011.02.007. PMID21334362. S2CID8735185.
^ abcBerenbaum SA, Beltz AM (April 2011). "Sexual differentiation of human behavior: effects of prenatal and pubertal organizational hormones". Frontiers in Neuroendocrinology. 32 (2): 183–200. doi:10.1016/j.yfrne.2011.03.001. PMID21397624. S2CID205776417.
^ abcdefBogaert AF, Blanchard R, Crosthwait LE (October 2007). "Interaction of birth order, handedness, and sexual orientation in the Kinsey interview data". Behavioral Neuroscience. 121 (5): 845–853. doi:10.1037/0735-7044.121.5.845. PMID17907817.
^ abBlanchard R, Lippa RA (April 2007). "Birth order, sibling sex ratio, handedness, and sexual orientation of male and female participants in a BBC internet research project". Archives of Sexual Behavior. 36 (2): 163–176. doi:10.1007/s10508-006-9159-7. PMID17345165. S2CID18868548.
^Blanchard R (January 2018). "Fraternal Birth Order, Family Size, and Male Homosexuality: Meta-Analysis of Studies Spanning 25 Years". Archives of Sexual Behavior. 47 (1): 1–15. doi:10.1007/s10508-017-1007-4. PMID28608293. S2CID10517373.
^Kishida M, Rahman Q (July 2015). "Fraternal Birth Order and Extreme Right-Handedness as Predictors of Sexual Orientation and Gender Nonconformity in Men". Archives of Sexual Behavior. 44 (5): 1493–1501. doi:10.1007/s10508-014-0474-0. PMID25663238. S2CID30678785.
^Francis AM (2008). "Family and sexual orientation: the family-demographic correlates of homosexuality in men and women". Journal of Sex Research. 45 (4): 371–377. doi:10.1080/00224490802398357. PMID18937128. S2CID20471773.
^Frisch M, Hviid A (October 2006). "Childhood family correlates of heterosexual and homosexual marriages: a national cohort study of two million Danes". Archives of Sexual Behavior. 35 (5): 533–547. doi:10.1007/s10508-006-9062-2. PMID17039403. S2CID21908113.
^Frisch M, Hviid A (2007-12-01). "Reply to Blanchard's (2007) "Older-Sibling and Younger-Sibling Sex Ratios in Frisch and Hviid's (2006) National Cohort Study of Two Million Danes"". Archives of Sexual Behavior. 36 (6): 864–867. doi:10.1007/s10508-007-9169-0. ISSN1573-2800. S2CID143749001.
^Mustanski BS, Bailey JM, Kaspar S (February 2002). "Dermatoglyphics, handedness, sex, and sexual orientation". Archives of Sexual Behavior. 31 (1): 113–122. doi:10.1023/A:1014039403752. PMID11910784. S2CID29217315.
^Rahman Q, Clarke K, Morera T (April 2009). "Hair whorl direction and sexual orientation in human males". Behavioral Neuroscience. 123 (2): 252–256. doi:10.1037/a0014816. PMID19331448. S2CID46164333.
^Witelson SF, Nowakowski RS (1991). "Left out axons make men right: a hypothesis for the origin of handedness and functional asymmetry". Neuropsychologia. 29 (4): 327–333. doi:10.1016/0028-3932(91)90046-B. PMID1857504. S2CID23754055.
^Sabuncuoglu O (March 2015). "Maternal Thyroid Dysfunction During Pregnancy May Lead to Same-sex Attraction/gender Nonconformity in the Offspring: Proposal of Prenatal Thyroid Model". European Psychiatry. 30: 374. doi:10.1016/s0924-9338(15)30294-7. ISSN0924-9338. S2CID143359069.
^Panzica GC, Aste N, Viglietti-Panzica C, Ottinger MA (March 1995). "Structural sex differences in the brain: influence of gonadal steroids and behavioral correlates". Journal of Endocrinological Investigation. 18 (3): 232–252. doi:10.1007/BF03347808. PMID7615911. S2CID10435075.
^Swaab DF, Zhou JN, Ehlhart T, Hofman MA (June 1994). "Development of vasoactive intestinal polypeptide neurons in the human suprachiasmatic nucleus in relation to birth and sex". Brain Research. Developmental Brain Research. 79 (2): 249–259. doi:10.1016/0165-3806(94)90129-5. PMID7955323.
^Brodie HK, Gartrell N, Doering C, Rhue T (January 1974). "Plasma testosterone levels in heterosexual and homosexual men". The American Journal of Psychiatry. 131 (1): 82–83. doi:10.1176/ajp.131.1.82. PMID4808435.
^Doerr P, Pirke KM, Kockott G, Dittmar F (May 1976). "Further studies on sex hormones in male homosexuals". Archives of General Psychiatry. 33 (5): 611–614. doi:10.1001/archpsyc.1976.01770050063010. PMID1267577.
^Neave N, Menaged M, Weightman DR (December 1999). "Sex differences in cognition: the role of testosterone and sexual orientation". Brain and Cognition. 41 (3): 245–262. doi:10.1006/brcg.1999.1125. PMID10585237. S2CID44831103.
^Byne W, Tobet S, Mattiace LA, Lasco MS, Kemether E, Edgar MA, et al. (September 2001). "The interstitial nuclei of the human anterior hypothalamus: an investigation of variation with sex, sexual orientation, and HIV status". Hormones and Behavior. 40 (2): 86–92. doi:10.1006/hbeh.2001.1680. PMID11534967. S2CID3175414. [permanent dead link]
^Byne W, Tobet S, Mattiace LA, Lasco MS, Kemether E, Edgar MA, et al. (September 2001). "The interstitial nuclei of the human anterior hypothalamus: an investigation of variation with sex, sexual orientation, and HIV status". Hormones and Behavior. 40 (2): 86–92. doi:10.1006/hbeh.2001.1680. PMID11534967. S2CID3175414.
^ abcdefPeplau L, Huppin M (October 2008). "Masculinity, Femininity and the Development of Sexual Orientation in Women". Journal of Gay & Lesbian Mental Health. 12 (1–2): 145–165. doi:10.1300/J529v12n01_09. S2CID142691272.
^ abGobrogge KL, Breedlove SM, Klump KL (February 2008). "Genetic and environmental influences on 2D:4D finger length ratios: a study of monozygotic and dizygotic male and female twins". Archives of Sexual Behavior. 37 (1): 112–118. doi:10.1007/s10508-007-9272-2. PMID18074216. S2CID41921265.
^Dittmann V, Dilling H (June 1990). "Chapter V (F) of ICD-10: mental, behavioural and developmental disorders--introduction and overview". Pharmacopsychiatry. 23 (suppl 4): 137–141. doi:10.1055/s-2007-1014552. PMID2197637. S2CID34081785.
^Dittmann V, von Cranach M, Eckermann G (June 1990). "Abnormalities of adult personality and behaviour (section F 6)--results of the ICD-10 field trial". Pharmacopsychiatry. 23 (Suppl 4): 170–172. doi:10.1055/s-2007-1014559. PMID2197643. S2CID24696932.
^Dittmann V (August 1992). "[ICD-10 in psychiatric diagnosis. The concept and initial practical experiences]". Versicherungsmedizin (in German). 44 (4): 114–119. PMID1509643.
^Zucker KJ, Bradley SJ, Oliver G, Blake J, Fleming S, Hood J (December 1996). "Psychosexual development of women with congenital adrenal hyperplasia". Hormones and Behavior. 30 (4): 300–318. doi:10.1006/hbeh.1996.0038. PMID9047259. S2CID20206538.
^Hines M, Brook C, Conway GS (February 2004). "Androgen and psychosexual development: core gender identity, sexual orientation and recalled childhood gender role behavior in women and men with congenital adrenal hyperplasia (CAH)". Journal of Sex Research. 41 (1): 75–81. doi:10.1080/00224490409552215. PMID15216426. S2CID33519930.
^ abWallien MS, Zucker KJ, Steensma TD, Cohen-Kettenis PT (August 2008). "2D:4D finger-length ratios in children and adults with gender identity disorder". Hormones and Behavior. 54 (3): 450–454. doi:10.1016/j.yhbeh.2008.05.002. PMID18585715. S2CID6324765.
^Meyer-Bahlburg HF (August 2005). "Gender identity outcome in female-raised 46,XY persons with penile agenesis, cloacal exstrophy of the bladder, or penile ablation". Archives of Sexual Behavior. 34 (4): 423–438. doi:10.1007/s10508-005-4342-9. PMID16010465. S2CID34971769.
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Ekonomi Ekonomi menurut kawasan Afrika · Amerika Amerika Selatan · Asia Eropa · Oseania Kategori umum Ekonomi mikro · Ekonomi makro Sejarah pemikiran ekonomi Metodologi · Pendekatan heterodoks Bidang dan subbidang Perilaku · Budaya · Evolusi Pertumbuhan · Pengembangan · Sejarah Internasional · Sistem ekonomi Keuangan dan Ekonomi keuangan Masyarakat dan Ekonomi ke...
Гонконгский международный аэропорт Основная программа аэропорта (Airport Core Programme, 香港機場核心計劃) представляет собой серию инфраструктурных проектов, реализованных в 1990-х годах в связи с постройкой нового Гонконгского международного аэропорта. Программа была частью бол...
Anne Elizabeth ApplebaumLahir25 Juli 1964 (umur 59)[1]Washington, D.C.Kebangsaan Amerika SerikatPendidikanB.A. 1986 (summa cum laude, Phi Beta Kappa)M.Sc., 1987AlmamaterYaleLondon School of EconomicsPekerjaanjurnalispenulisDikenal atasKarya pemenang penghargaan tentang bekas Uni Soviet dan negara satelitnyaKota asalWashington, D.C.Suami/istriRadosław Sikorski sejak 27 Juni 1992AnakAlexander, TadeuszOrang tuaHarvey M. ApplebaumElizabeth (Bloom) ApplebaumSitus webAnne A...
Head of VA before it was a Department The Administrator of Veterans Affairs was the head of the Veterans Administration, a United States Government agency responsible for military veterans benefits. The administrator was appointed by the President. In 1989, the Veterans Administration was replaced by the United States Department of Veterans Affairs, with the Secretary of Veterans Affairs (a member of the cabinet) as its head. The last VA administrator, Derwinski, went on to become the first S...
Lophophorata BryozoaBrachiopodTaksonomiKerajaanAnimaliaTanpa nilaiLophophorata Klad †Tommotiida (paraphyletic) Brachiozoa Bryozoa s.l. lbs Lophophorata atau Tentaculata adalah sebuah klad lophotrochozoa yang terdiri dari Brachiozoa dan Bryozoa,[1][2][3][4] yang ditandai dengan adanya lofofor. Analisis filogenetika molekuler menyarankan bahwa Lophophorata merupakan protostomia, namun secara morfologi, mereka diklasifikasikan sebagai deuterostomia.[5] C...
Three person research deep-submergence vehicles History United States NamePisces IV and Pisces V OwnerNational Oceanic and Atmospheric Administration OperatorHawaii Undersea Research Laboratory BuilderHyco International Hydrodynamics, North Vancouver CompletedEarly 1970s General characteristics Displacement13,000kg Length6.10 m (20 ft 0 in) Beam3.20 m (10 ft 6 in) Height3.35 m (11 ft 0 in) Propulsion2 × side-mounted reversible thrusters tiltable t...
Ini adalah nama Melayu; nama Ramli merupakan patronimik, bukan nama keluarga, dan tokoh ini dipanggil menggunakan nama depannya, Rafizi. Kata bin (b.) atau binti (bt.), jika digunakan, berarti putra dari atau putri dari. Yang Berhormat TuanRafizi Ramliرافيزي رمليRafizi, c. 2023 Menteri Ekonomi MalaysiaPetahanaMulai menjabat 3 Desember 2022Perdana MenteriAnwar IbrahimWakilHanifah Hajar TaibPendahuluMustapa Mohamed sebagai Menteri di Sekretariat Perdana MenteriPenggantiPetahanaDep...
У этого термина существуют и другие значения, см. Чайки (значения). Чайки Доминиканская чайкаЗападная чайкаКалифорнийская чайкаМорская чайка Научная классификация Домен:ЭукариотыЦарство:ЖивотныеПодцарство:ЭуметазоиБез ранга:Двусторонне-симметричныеБез ранга:Вторич...
Partai Sosial Liberal Partido Social LiberalPresidenLuciano BivarDibentuk30 Oktober 1994 (1994-10-30) (didirikan)2 Juni 1998 (1998-06-02) (terdaftar)Kantor pusatSHN, Quadra 02, Bloco F, Ed. Executive Office Tower, Sala 1.122 - Brasília (DF)Keanggotaan (Juli 2018)241.439[1]IdeologiKonservatisme nasionalKonservatsisme fiskalLiberalisme ekonomiNasionalisme BrasilPopulisme sayap kananMiliterisme[2]Antikomunisme[3]Minoritas:Monarkisme[4][5][6&...
هذه قائمة بالأفلام والمسلسلات التلفزيونية من وجهة نظر إسلامية، والمتعلقة بالحضارة الإسلامية، أي الإسلام والتاريخ الإسلامي والثقافة الإسلامية، تميل أغلب الأفلام والمسلسلات إلى تصوير المرأة بالحجاب، وتتوفر معظمها مع ترجمات ودبلجة بلغات متعددة.[1][2][3] مسلسلات...
The HonourableMoses Veerasammy NagamootooAPமோசஸ் வீராசாமி நாகமுத்துcode: ta is deprecated (Tamil) Perdana Menteri ke-8 dan Wakil Presiden GuyanaMasa jabatan20 Mei 2015 – 2 Agustus 2020 Menjabat bersama dengan Carl Barrington Greenidge, Khemraj Ramjattan dan Sydney AllicockPresidenDavid A. GrangerPendahuluSam HindsPenggantiMark Phillips Informasi pribadiLahir30 November 1947 (umur 76)Whim, Berbice, Guiana Britania (saat in...
American politician from Illinois (1927–2014) For the English cricketer, see Alan Dixon (cricketer). Alan J. DixonUnited States Senatorfrom IllinoisIn officeJanuary 3, 1981 – January 3, 1993Preceded byAdlai Stevenson IIISucceeded byCarol Moseley Braun34th Secretary of State of IllinoisIn officeJanuary 10, 1977 – January 12, 1981GovernorJames R. ThompsonPreceded byMichael HowlettSucceeded byJim Edgar65th Treasurer of IllinoisIn officeJanuary 11, 1971 – Januar...
State park in Virginia, USA First Landing State ParkIUCN category III (natural monument or feature)Cypress swamp at First Landing State ParkLocation of First Landing State ParkShow map of VirginiaFirst Landing State Park (the United States)Show map of the United StatesLocationVirginia Beach, Virginia, USACoordinates36°54′22″N 76°0′55″W / 36.90611°N 76.01528°W / 36.90611; -76.01528Area2,888 acres (11.69 km2)Visitors1,000,000+ (in 2004)Governing...
Olga EnglLahir(1871-05-30)30 Mei 1871Prague, Austria-HungariaMeninggal21 September 1946(1946-09-21) (umur 75)Berlin, JermanPekerjaanAktorTahun aktif1887–1945 Olga Engl (30 Mei 1871; Prague – 21 September 1946; Berlin) merupakan seorang Artis film Austria yang muncul hampir 200 film selama kariernya di industri film. Olga Engl adalah pribadi yang berpendidikan di sebuah biara tunggal-seks dan memulai karier aktingnya di Praha Konservatori. Pada Agustus 1887 ia membuat debut pang...
Highest court of authority of Zambia for non-consistutional law Supreme Court of ZambiaJurisdictionZambiaAuthorized byArticle 124, Constitution of ZambiaAppeals fromCourt of AppealNumber of positionsnot less than 13Websitejudiciaryzambia.com/supreme-court/Chief JusticeCurrentlyMumba MalilaSince2021Deputy Chief JusticeCurrentlyMichael MusondaSince2019 Politics of Zambia Constitution Human rights Government President Hakainde Hichilema Vice-President Mutale Nalumango Cabinet Legislature Nationa...
For the former municipality of Aldingen am Neckar, see Remseck. Municipality in Baden-Württemberg, GermanyAldingen Municipality FlagCoat of armsLocation of Aldingen within Tuttlingen district Aldingen Show map of GermanyAldingen Show map of Baden-WürttembergCoordinates: 48°05′40″N 08°42′21″E / 48.09444°N 8.70583°E / 48.09444; 8.70583CountryGermanyStateBaden-WürttembergAdmin. regionFreiburg DistrictTuttlingen Government • Mayor (2021–29)...
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