Finger-Length Ratios in Female Monozygotic Twins Discordant for Sexual Orientation

@article{Hall2003FingerLengthRI,
  title={Finger-Length Ratios in Female Monozygotic Twins Discordant for Sexual Orientation},
  author={Lynn S. Hall and Craig T. Love},
  journal={Archives of Sexual Behavior},
  year={2003},
  volume={32},
  pages={23-28}
}
The second to fourth finger digit ratio (2D:4D ratio) is a sex-dimorphic characteristic in humans that may reflect relative levels of first trimester prenatal sex hormones. Low interdigital ratio has been associated with high levels of androgens. It has been reported in unrelated women that low 2D:4D ratio is associated with lesbian sexual orientation, but because of the nature of those samples, it was not possible to conclude whether lower ratio (and hypothetically, higher androgen levels) in… 
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72 Citations
Highly Influential Citations
3
Background Citations
21
Methods Citations
3
Results Citations
3

72 Citations

Prenatal Influences on Sexual Orientation: Digit Ratio (2D:4D) and Number of Older Siblings
Prenatal androgen levels are suggested to influence sexual orientation in both sexes. The 2D:4D digit ratio has been found to associate with sexual orientation, but published findings have often been…
Sexual orientation and the second to fourth finger length ratio: a meta-analysis in men and women.
TLDR
It is found that heterosexual women had higher (more feminine) left- and right-hand 2D:4D than did lesbians, but there was no difference between heterosexual and gay men.
Genetic and Environmental Influences on 2D:4D Finger Length Ratios: A Study of Monozygotic and Dizygotic Male and Female Twins
TLDR
Biometric model-fitting analyses indicated significant additive genetic and nonshared environmental influences on digit ratios in twins, and suggest greater similarity between 2D:4D ratios in MZ relative to DZ twins that can be accounted for by genetic and nontraditional environmental factors.
Intrauterine Position Effects on Anogenital Distance and Digit Ratio in Male and Female Mice
TLDR
The lack of correlation between 2D:4D and AGDs in this mouse strain suggests that these two measures do not reflect a common influence of androgen exposure, and the possible roles of temporal and localized effects of masculinization are discussed.
The Discordant Development of Sexual Orientation in Identical Twins
TLDR
Results suggested that these twins differed in many (but not in all) correlates of their sexual orientation, suggesting non-genetic influences, however, there were also subtle similarities within pairs that pointed to potential familial influences.
Finger-length ratios show evidence of prenatal hormone-transfer between opposite-sex twins
Sex dimorphism in digital formulae of children.
TLDR
Test for a sex difference in the relative lengths of the finger bones, including the second-to-fourth digit ratio (2D:4D), using left-hand radiographs taken in young children indicate that relative digit lengths are sex-dimorphic in children, and suggests that 3D: 4D may be a better marker of perinatal sex differentiation.
The Second to Fourth Digit Ratio (2D:4D) in a Japanese Twin Sample: Heritability, Prenatal Hormone Transfer, and Association with Sexual Orientation
TLDR
The existence of non-shared environmental influences that affect both 2D:4D and sexual orientation are suggested, which are in the predicted direction according to the prenatal hormone transfer hypothesis.
Testing the prenatal androgen hypothesis: measuring digit ratios, sexual orientation, and spatial abilities in adults
Through a glass, darkly: Human digit ratios reflect prenatal androgens, imperfectly
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