Sexual orientation and the 2nd to 4th finger length ratio: evidence for organising effects of sex hormones or developmental instability?

Rahman, Qazi; Wilson, Glenn D.

doi:10.1016/s0306-4530(02)00022-7

Cited by 125 publications

(119 citation statements)

References 42 publications

Supporting

Mentioning

106

Contrasting

Unclassified

Order By: Relevance

“…The 2D:4D of gay males has been described as hypermasculinized (lower) in some reports or hypomasculinized (higher) in other studies (Lippa, 2003;Manning et al, 2007;McFadden et al, 2005;McFadden & Shubel, 2002;Rahman & Wilson, 2003;Robinson & Manning, 2000;Voracek, Manning, & Ponocny, 2005;Williams et al, 2000). The correlation between sexual orientation and 2D:4D in women seems more consistent.…”

Section: Introductionmentioning

confidence: 84%

“…The correlation between sexual orientation and 2D:4D in women seems more consistent. In most studies, lesbians exhibited a more masculinized (lower) 2D:4D than heterosexual women (Kraemer et al, 2006;McFadden & Shubel, 2002;Rahman & Wilson, 2003;Williams et al, 2000) compared to heterosexuals. It is perhaps worth noting that Lippa (2003) and Manning et al (2007) could not confirm this finding.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Finger Length Ratio (2D:4D) in Adults with Gender Identity Disorder

et al. 2007

View full text Add to dashboard Cite

From early childhood, gender identity and the 2nd to 4th finger length ratio (2D:4D) are discriminative characteristics between sexes. Both the human brain and 2D:4D may be influenced by prenatal testosterone levels. This calls for an examination of 2D:4D in patients with gender identity disorder (GID) to study the possible influence of prenatal testosterone on gender identity. Until now, the only study carried out on this issue suggests lower prenatal testosterone levels in right-handed male-to-female GID patients (MtF). We compared 2D:4D of 56 GID patients (39 MtF; 17 female-to-male GID patients, FtM) with data from a control sample of 176 men and 190 women. Bivariate group comparisons showed that right hand 2D:4D in MtF was significantly higher (feminized) than in male controls, but similar to female controls. The comparison of 2D:4D ratios of biological women revealed significantly higher (feminized) values for right hands of right handed FtM. Analysis of variance confirmed significant effects for sex and for gender identity on 2D:4D ratios but not for sexual orientation or for the interaction among variables. Our results indirectly point to the possibility of a weak influence of reduced prenatal testosterone as an etiological factor in the multifactorially influenced development of MtF GID. The development of FtM GID seems even more unlikely to be notably influenced by prenatal testosterone. Analysis of variance confirmed significant effects for sex and for gender identity on 2D:4D ratios but not for sexual orientation or for the interaction among variables. Our results indirectly point to the possibility of a weak influence of reduced prenatal testosterone as an etiological factor in the multifactorially influenced development of MtF GID. The development of FtM GID seems even more unlikely to be notably influenced by prenatal testosterone.

show abstract

Section: Introductionmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Finger Length Ratio (2D:4D) in Adults with Gender Identity Disorder

et al. 2007

View full text Add to dashboard Cite

show abstract

“…On the one hand, homosexual men were hypothesized to be exposed to high levels of testosterone in utero, which would be associated with a lower 2D:4D ratio than that found in heterosexual men. Two studies found this to be the case [241,242], but one did not [243]. On the other hand, homosexual men have been hypothesized to have low prenatal testosterone exposure, and data from two studies are consistent with that hypothesis [244,245], showing homosexual men to have a higher finger ratio (on both hands) than heterosexual men; one study was large and considered effects of ethnicity [244].…”

Section: Sexual Orientationmentioning

confidence: 96%

Prenatal sex hormone effects on child and adult sex-typed behavior: methods and findings

Cohen-Bendahan

Beek

Berenbaum

2005

Neuroscience & Biobehavioral Reviews

480

400

View full text Add to dashboard Cite

There is now good evidence that human sex-typed behavior is influenced by sex hormones that are present during prenatal development, confirming studies in other mammalian species. Most of the evidence comes from clinical populations, in which prenatal hormone exposure is atypical for a person's sex, but there is increasing evidence from the normal population for the importance of prenatal hormones. In this paper, we briefly review the evidence, focusing attention on the methods used to study behavioral effects of prenatal hormones. We discuss the promises and pitfalls of various types of studies, including those using clinical populations (concentrating on those most commonly studied, congenital adrenal hyperplasia, androgen insensitivity syndrome, ablatio penis, and cloacal exstrophy), direct measures of hormones in the general population (assayed through umbilical cord blood, amniotic fluid, and maternal serum during pregnancy), and indirect measures of hormones in the general population (inferred from intrauterine position and biomarkers such as otoacoustic emissions, finger length ratios, and dermatoglyphic asymmetries). We conclude with suggestions for interpreting and conducting studies of the behavioral effects of prenatal hormones. q

show abstract

“…musical abilities (Robinson and Manning, 2000;Williams et al, 2000;Manning and Taylor, 2001;Austin et al, 2002;McFadden and Shubel, 2002;Csathò et al, 2003;Neave et al, 2003;Rahman and Wilson, 2003;Putz et al, 2004;Bailey and Hurd, 2005). Positive correlations with 2D:4D have been observed for verbal semantic fluency and traits such as age of onset of myocardial infarction in men or breast cancer in women .…”

mentioning

confidence: 99%

Sexual dimorphism in metapodial and phalanges length ratios in the wood mouse

2005

View full text Add to dashboard Cite

Relative length of metapodials and digits is sexually dimorphic in most primates and one rodent and one bird species studied so far. Recently, interest in digit ratios has increased because of their correlation with diverse physiological, psychological, and performance traits in humans. These correlations may reflect the effect of androgens during early ontogeny on digit development and their long-term organizational effects on extragenital organs. Inter-and intrasexual variation in digit ratios may be ultimately controlled by modulation of the expression of Hoxa and Hoxd genes. Since Hox genes are conserved in vertebrates, similar patterns of sex-related variation in length ratios may be expected across taxa. In fact, sexual dimorphism in length ratios has been documented for metapodials or digit bones in nonhuman vertebrates, but the specific pattern of sex-related variation varies considerably. However, no study has investigated sexual dimorphism in length ratios between all ray segments (metapodials plus phalanges) using osteometrical measures. In an outbred wild population of wood mice (Apodemus sylvaticus), we found extensive sex-related variation in ratios between osteometrical length of the phalanges, but not metatarsals, similar to that recorded on undissected digits of humans and laboratory mice. Most sexually dimorphic ratios involved the second digit. We found very weak evidence for directional asymmetry in length ratios. The present study shows that sex-related variation in length ratios between digit segments observed in mammals may actually depend on relative bone length. Hence, other species may be used to investigate the causal and semeiotic implications of variation in human digit ratios.

show abstract

Sexual orientation and the 2nd to 4th finger length ratio: evidence for organising effects of sex hormones or developmental instability?

Cited by 125 publications

References 42 publications

Finger Length Ratio (2D:4D) in Adults with Gender Identity Disorder

Finger Length Ratio (2D:4D) in Adults with Gender Identity Disorder

Prenatal sex hormone effects on child and adult sex-typed behavior: methods and findings

Sexual dimorphism in metapodial and phalanges length ratios in the wood mouse

Contact Info

Product

Resources

About