Differences in digit ratios between gay men who prefer receptive versus insertive sex roles indicate a role for prenatal androgen

AbstractAmong non-human mammals, exposure to androgens during critical periods of development leads to gynephilia (attraction to females), whereas the absence or low levels of prenatal androgens leads to androphilia (attraction to males). However, in humans, retrospective markers of prenatal androgens have only been associated with gynephilia among women, but not with androphilia among men. Here, we asked whether an indirect indication of prenatal androgen exposure, 2D:4D, differs between subsets of gay men delineated by anal sex role (ASR). ASR was used as a proxy for subgroups because ASR groups tend to differ in other measures affected by brain sexual differentiation, such as gender conformity. First, we replicated the finding that gay men with a receptive ASR preference (bottoms) report greater gender nonconformity (GNC) compared to gay men with an insertive ASR preference (tops). We then found that Tops have a lower (male-typical) average right-hand digit ratio than Bottoms, and that among all gay men the right-hand 2D:4D correlated with GNC, indicating that a higher (female-typical) 2D:4D is associated with increased GNC. Differences were found between non-exclusive and exclusive same-sex attraction and GNC, and ASR group differences on digit ratios do not reach significance when all non-heterosexual men are included in the analyses, suggesting greater heterogeneity in the development of non-exclusive same-sex sexual orientations. Overall, results support a role for prenatal androgens, as approximated by digit ratios, in influencing the sexual orientation and GNC of a subset of gay men.

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EVIDENCE FOR ASSORTATIVE MATING ON DIGIT RATIO (2D:4D), A BIOMARKER FOR PRENATAL ANDROGEN EXPOSURE

Journal of Biosocial Science ◽

10.1017/s0021932006001647 ◽

2007 ◽

Vol 39 (4) ◽

pp. 599-612 ◽

Cited By ~ 32

Author(s):

MARTIN VORACEK ◽

STEFAN G. DRESSLER ◽

JOHN T. MANNING

Keyword(s):

Assortative Mating ◽

Age Differences ◽

Research Programme ◽

Digit Ratio ◽

Left Hand ◽

Right Hand ◽

Androgen Exposure ◽

The Right ◽

Prenatal Androgen ◽

Spousal Similarity

SummaryThe second-to-fourth digit ratio (2D:4D) presents an anatomical sex difference in humans. On average, men tend to have lower 2D:4D compared with women. There is fairly strong evidence for a role of the 2D:4D ratio as a biomarker for the organizational (permanent) effects of prenatal testosterone on the brain and behaviour. Recently, an accumulating research programme has shown 2D:4D to be related to a multitude of sex-dependent, hormonally influenced biosocial traits and phenotypes which reach into the domains of ability, behaviour, fertility, health, personality and sexuality. This study investigated the degree of assortative mating (spousal similarity) in a sample of 239 native Austrian couples of parental or grandparental age, all of them having reproduced. Results included: (i) significant spousal correlations of +0·19 and +0·18 for right-hand and left-hand 2D:4D, respectively, and +0·24 for average 2D:4D; (ii) no assortative mating effect on the right-minus-left difference in 2D:4D; (iii) indications consistent with a possible generational decrease of spousal similarity in 2D:4D; (iv) a prevalence of couples with a lower right-hand 2D:4D observed in the husband compared with his wife; and (v) relations of spousal 2D:4D patterns to spousal age differences, such that matings of men with more male-typical trait expressions (namely, a generally low right-hand 2D:4D or showing a lower right-minus-left 2D:4D difference than their wives) implicated larger male-minus-female age differences, i.e. younger wives. It is argued that assortative mating on 2D:4D operates indirectly and may be mediated through the assortment on other, more perceptible, physical traits and psychological phenotypes that entertain associations with 2D:4D and are relevant for courtship and mate choice.

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Neuroendocrine Influences on Human Sexuality

Oxford Research Encyclopedia of Neuroscience ◽

10.1093/acrefore/9780190264086.013.250 ◽

2019 ◽

Cited By ~ 1

Author(s):

Ashlyn Swift-Gallant ◽

S. Marc Breedlove

Keyword(s):

Sexual Orientation ◽

Gay Men ◽

Sexual Partners ◽

Anal Sex ◽

Gender Nonconforming ◽

Androgen Exposure ◽

Prenatal Androgens ◽

Prenatal Androgen Exposure ◽

Prenatal Androgen ◽

Neuroendocrine Factors

While prenatal sex hormones guide the development of sex-typical reproductive structures, they also act on the developing brain, resulting in sex differences in brain and behavior in animal models. Stemming from this literature is the prominent hypothesis that prenatal neuroendocrine factors underlie sex differences in human sexual orientation, to explain why most males have a preference for female sexual partners (gynephilia), whereas most females display a preference for male sexual partners (androphilia). Convergent evidence from experiments of nature and indirect markers of prenatal hormones strongly support a role for prenatal androgens in same-same sexual orientations in women, although this finding is specific to a subset of lesbians who are also gender nonconforming (“butch”). More gender-conforming lesbians (“femmes”) do not show evidence of increased prenatal androgens. The literature has been more mixed for male sexual orientation: some report evidence of low prenatal androgen exposure, while others report evidence of high androgen levels and many other studies find no support for a role of prenatal androgen exposure in the development of androphilia in males. Recent evidence suggests there may be subgroups of gay men who owe their sexual orientation to distinct biodevelopmental mechanisms, which could account for these mixed findings. Although this research is young, it is similar to findings from lesbian populations, because gay men who are more gender nonconforming, and report a preference for receptive anal sex, differ on markers of prenatal development from gay men who are more gender conforming and report a preference for insertive anal sex. This chapter concludes with future research avenues including assessing whether multiple biodevelopmental pathways underlie sexual orientation and whether neuroendocrine factors and other biological mechanisms (e.g., immunology, genetics) interact to promote a same-sex sexual orientation.

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Gender Nonconformity and Birth Order in Relation to Anal Sex Role Among Gay Men

Archives of Sexual Behavior ◽

10.1007/s10508-017-0980-y ◽

2017 ◽

Vol 47 (4) ◽

pp. 1041-1052 ◽

Cited By ~ 10

Author(s):

Ashlyn Swift-Gallant ◽

Lindsay A. Coome ◽

D. Ashley Monks ◽

Doug P. VanderLaan

Keyword(s):

Birth Order ◽

Gay Men ◽

Sex Role ◽

Gender Nonconformity ◽

Anal Sex

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Handedness is a biomarker of variation in anal sex role behavior and Recalled Childhood Gender Nonconformity among gay men

PLoS ONE ◽

10.1371/journal.pone.0170241 ◽

2017 ◽

Vol 12 (2) ◽

pp. e0170241 ◽

Cited By ~ 7

Author(s):

Ashlyn Swift-Gallant ◽

Lindsay A. Coome ◽

D. Ashley Monks ◽

Doug P. VanderLaan

Keyword(s):

Gay Men ◽

Sex Role ◽

Gender Nonconformity ◽

Anal Sex ◽

Role Behavior ◽

Childhood Gender ◽

Childhood Gender Nonconformity

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Minireview: Organizational Hypothesis: Instances of the Fingerpost

Endocrinology ◽

10.1210/en.2010-0041 ◽

2010 ◽

Vol 151 (9) ◽

pp. 4116-4122 ◽

Cited By ~ 139

Author(s):

S. Marc Breedlove

Keyword(s):

Attention Deficit Disorder ◽

Receptor Gene ◽

Androgen Receptor Gene ◽

Androgen Insensitivity Syndrome ◽

Fetal Life ◽

Human Behaviors ◽

Digit Ratios ◽

Prenatal Androgens ◽

Valid Test ◽

Prenatal Androgen

There is now compelling evidence that the ratio of the length of the second digit divided by the length of the fourth digit (2D:4D) is affected by prenatal androgens in humans. This ratio is greater in females than males from fetal life through adulthood, correlates with polymorphism in the androgen receptor gene in men, is feminine in XY androgen insensitivity syndrome, and masculinized in congenital adrenal hyperplasia. Using 2D:4D as a correlate, researchers have found evidence that prenatal androgens affect many sexually differentiated human behaviors, including sexual orientation in women (but not in men), attention deficit disorder, autism, eating disorders, aggression, and risk-taking. In each case, lower 2D:4D, indicative of greater prenatal androgen stimulation, is associated with behavior more commonly displayed by males than females. The correlation between 2D:4D and prenatal androgen stimulation is too imperfect to accurately predict the phenotype of a particular individual, even in terms of sex. However, digit ratio is the best available retrospective marker of average differences in prenatal androgen stimulation between groups of people, and/or correlations of prenatal androgen stimulation with particular behaviors and characteristics within a group. Thus digit ratios offer a valid test of the organizational hypothesis that androgens act early in life to masculinize various human behaviors.

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Editorial Note

Journal of Speech Disorders ◽

10.1044/jshd.1101.02 ◽

1946 ◽

Vol 11 (1) ◽

pp. 2-2

Keyword(s):

Editorial Note ◽

Speech Sounds ◽

Left Hand ◽

Hand Column ◽

Right Hand ◽

Infant Speech ◽

The Right

In the article “Infant Speech Sounds and Intelligence” by Orvis C. Irwin and Han Piao Chen, in the December 1945 issue of the Journal, the paragraph which begins at the bottom of the left hand column on page 295 should have been placed immediately below the first paragraph at the top of the right hand column on page 296. To the authors we express our sincere apologies.

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Eosinophilic vasculitis: an inhabitual and resistant manifestation of a vasculitis

VASA ◽

10.1024/0301-1526/a000060 ◽

2010 ◽

Vol 39 (4) ◽

pp. 344-348 ◽

Cited By ~ 3

Author(s):

Jandus ◽

Bianda ◽

Alerci ◽

Gallino ◽

Marone

Keyword(s):

Skin Biopsy ◽

Intravenous Iron ◽

Small Vessel Vasculitis ◽

High Dose ◽

Raynaud Phenomenon ◽

The Third ◽

Left Elbow ◽

Right Hand ◽

The Right ◽

Trunk Skin

A 55-year-old woman was referred because of diffuse pruritic erythematous lesions and an ischemic process of the third finger of her right hand. She was known to have anaemia secondary to hypermenorrhea. She presented six months before admission with a cutaneous infiltration on the left cubital cavity after a paravenous leakage of intravenous iron substitution. She then reported a progressive pruritic erythematous swelling of her left arm and lower extremities and trunk. Skin biopsy of a lesion on the right leg revealed a fibrillar, small-vessel vasculitis containing many eosinophils.Two months later she reported Raynaud symptoms in both hands, with a persistent violaceous coloration of the skin and cold sensation of her third digit of the right hand. A round 1.5 cm well-delimited swelling on the medial site of the left elbow was noted. The third digit of her right hand was cold and of violet colour. Eosinophilia (19 % of total leucocytes) was present. Doppler-duplex arterial examination of the upper extremities showed an occlusion of the cubital artery down to the palmar arcade on the right arm. Selective angiography of the right subclavian and brachial arteries showed diffuse alteration of the blood flow in the cubital artery and hand, with fine collateral circulation in the carpal region. Neither secondary causes of hypereosinophilia nor a myeloproliferative process was found. Considering the skin biopsy results and having excluded other causes of eosinophilia, we assumed the diagnosis of an eosinophilic vasculitis. Treatment with tacrolimus and high dose steroids was started, the latter tapered within 12 months and then stopped, but a dramatic flare-up of the vasculitis with Raynaud phenomenon occurred. A new immunosupressive approach with steroids and methotrexate was then introduced. This case of aggressive eosinophilic vasculitis is difficult to classify into the usual forms of vasculitis and constitutes a therapeutic challenge given the resistance to current immunosuppressive regimens.

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