The second to fourth digit ratio (2D: 4D) in a Japanese twin sample: Heritability, prenatal hormone transfer, and association with sexual orientation

Kai Hiraishi, Shoko Sasaki, Chizuru Shikishima, Jyukou Andou

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

The second to fourth digit ratio has been argued to reflect prenatal hormonal influences and is reportedly associated with various psychological and behavioral traits, such as sexual orientation, cognitive abilities, andpersonality.We examined geneticandenvironmental influencesonthe secondto fourth digit ratio (2D:4D)using a Japanese twin sample (N=300).The genetic analysis showed substantial additive genetic influences for both right and left hand 2D:4D. The rest of the variancewas explainedmainly by environmental influences not shared within twin pairs.Thesefindings were,ingeneral, inaccordancewithpreceding studies with primarilyCaucasiantwinsamples. Thebivariate genetic analysis revealed that the additive genetic influences were largely shared between the right and left hand, while the non-shared environmental influences were largely unique to each hand. Results from a comparison of opposite-sex and same-sex twins were not significant, although they were in the predicted direction according to the prenatal hormone transfer hypothesis. Female monozygotic twin pairs discordant in sexual orientation showed significant within-pair differences in left hand 2D:4D, where non-heterosexual twins had lower (more masculinized) 2D:4D. In addition, we found that non-heterosexual male MZ twinshadlarger (morefeminized)2D:4Dthantheir heterosexual co-Twins. These results suggest the existence of non-shared environmental influences that affect both 2D:4D and sexual orientation.

Original languageEnglish
Pages (from-to)711-724
Number of pages14
JournalArchives of Sexual Behavior
Volume41
Issue number3
DOIs
Publication statusPublished - 2012 Jun

Fingerprint

Sexual Behavior
Hormones
Hand
Aptitude
Monozygotic Twins
Heterosexuality
Sexual Orientation
Heritability
Psychology
Environmental Influences
Sexual Minorities

Keywords

  • 2D:4D
  • Finger-length ratios
  • Heritability
  • Prenatal hormone transfer
  • Sexual orientation
  • Twins

ASJC Scopus subject areas

  • Psychology(all)
  • Arts and Humanities (miscellaneous)

Cite this

@article{68bf03c570364506bb773390232b047f,
title = "The second to fourth digit ratio (2D: 4D) in a Japanese twin sample: Heritability, prenatal hormone transfer, and association with sexual orientation",
abstract = "The second to fourth digit ratio has been argued to reflect prenatal hormonal influences and is reportedly associated with various psychological and behavioral traits, such as sexual orientation, cognitive abilities, andpersonality.We examined geneticandenvironmental influencesonthe secondto fourth digit ratio (2D:4D)using a Japanese twin sample (N=300).The genetic analysis showed substantial additive genetic influences for both right and left hand 2D:4D. The rest of the variancewas explainedmainly by environmental influences not shared within twin pairs.Thesefindings were,ingeneral, inaccordancewithpreceding studies with primarilyCaucasiantwinsamples. Thebivariate genetic analysis revealed that the additive genetic influences were largely shared between the right and left hand, while the non-shared environmental influences were largely unique to each hand. Results from a comparison of opposite-sex and same-sex twins were not significant, although they were in the predicted direction according to the prenatal hormone transfer hypothesis. Female monozygotic twin pairs discordant in sexual orientation showed significant within-pair differences in left hand 2D:4D, where non-heterosexual twins had lower (more masculinized) 2D:4D. In addition, we found that non-heterosexual male MZ twinshadlarger (morefeminized)2D:4Dthantheir heterosexual co-Twins. These results suggest the existence of non-shared environmental influences that affect both 2D:4D and sexual orientation.",
keywords = "2D:4D, Finger-length ratios, Heritability, Prenatal hormone transfer, Sexual orientation, Twins",
author = "Kai Hiraishi and Shoko Sasaki and Chizuru Shikishima and Jyukou Andou",
year = "2012",
month = "6",
doi = "10.1007/s10508-011-9889-z",
language = "English",
volume = "41",
pages = "711--724",
journal = "Archives of Sexual Behavior",
issn = "0004-0002",
publisher = "Springer New York",
number = "3",

}

TY - JOUR

T1 - The second to fourth digit ratio (2D

T2 - 4D) in a Japanese twin sample: Heritability, prenatal hormone transfer, and association with sexual orientation

AU - Hiraishi, Kai

AU - Sasaki, Shoko

AU - Shikishima, Chizuru

AU - Andou, Jyukou

PY - 2012/6

Y1 - 2012/6

N2 - The second to fourth digit ratio has been argued to reflect prenatal hormonal influences and is reportedly associated with various psychological and behavioral traits, such as sexual orientation, cognitive abilities, andpersonality.We examined geneticandenvironmental influencesonthe secondto fourth digit ratio (2D:4D)using a Japanese twin sample (N=300).The genetic analysis showed substantial additive genetic influences for both right and left hand 2D:4D. The rest of the variancewas explainedmainly by environmental influences not shared within twin pairs.Thesefindings were,ingeneral, inaccordancewithpreceding studies with primarilyCaucasiantwinsamples. Thebivariate genetic analysis revealed that the additive genetic influences were largely shared between the right and left hand, while the non-shared environmental influences were largely unique to each hand. Results from a comparison of opposite-sex and same-sex twins were not significant, although they were in the predicted direction according to the prenatal hormone transfer hypothesis. Female monozygotic twin pairs discordant in sexual orientation showed significant within-pair differences in left hand 2D:4D, where non-heterosexual twins had lower (more masculinized) 2D:4D. In addition, we found that non-heterosexual male MZ twinshadlarger (morefeminized)2D:4Dthantheir heterosexual co-Twins. These results suggest the existence of non-shared environmental influences that affect both 2D:4D and sexual orientation.

AB - The second to fourth digit ratio has been argued to reflect prenatal hormonal influences and is reportedly associated with various psychological and behavioral traits, such as sexual orientation, cognitive abilities, andpersonality.We examined geneticandenvironmental influencesonthe secondto fourth digit ratio (2D:4D)using a Japanese twin sample (N=300).The genetic analysis showed substantial additive genetic influences for both right and left hand 2D:4D. The rest of the variancewas explainedmainly by environmental influences not shared within twin pairs.Thesefindings were,ingeneral, inaccordancewithpreceding studies with primarilyCaucasiantwinsamples. Thebivariate genetic analysis revealed that the additive genetic influences were largely shared between the right and left hand, while the non-shared environmental influences were largely unique to each hand. Results from a comparison of opposite-sex and same-sex twins were not significant, although they were in the predicted direction according to the prenatal hormone transfer hypothesis. Female monozygotic twin pairs discordant in sexual orientation showed significant within-pair differences in left hand 2D:4D, where non-heterosexual twins had lower (more masculinized) 2D:4D. In addition, we found that non-heterosexual male MZ twinshadlarger (morefeminized)2D:4Dthantheir heterosexual co-Twins. These results suggest the existence of non-shared environmental influences that affect both 2D:4D and sexual orientation.

KW - 2D:4D

KW - Finger-length ratios

KW - Heritability

KW - Prenatal hormone transfer

KW - Sexual orientation

KW - Twins

UR - http://www.scopus.com/inward/record.url?scp=84864036861&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84864036861&partnerID=8YFLogxK

U2 - 10.1007/s10508-011-9889-z

DO - 10.1007/s10508-011-9889-z

M3 - Article

C2 - 22270254

AN - SCOPUS:84864036861

VL - 41

SP - 711

EP - 724

JO - Archives of Sexual Behavior

JF - Archives of Sexual Behavior

SN - 0004-0002

IS - 3

ER -