Twin gay

Human same-sex sexual attraction has been recorded from the beginning of written history. It remains a controversial topic, but recent theories favor prenatal influences. Variation in the distribution of these mitochondria in neural precursor cells becomes a mechanism for the development of intrinsic sexual orientation and for the spectrum of human sexual inclinations.

Do identical twins who share almost % of their DNA also share the same sexual identity? We advertised for identical twins with discordant sexual orientations via newsletters at UK universities, social media sites, online news sites for gay men and lesbians, and at three gay Pride.

Share sensitive information only on official, secure websites. Keywords: mtdna haplogroups, handedness, hamilton's rule, kin selection, gender dysphoria, mitochondria, sexual orientation, monozygous twins, sexual orientation twins, homosexuality.

If sexual orientation was entirely genetically determined monozygous twins would be expected to have identical sexual inclinations. We asked two Melbourne twins to discuss what that difference meant gay them. The factors resulting in same-sex sexual orientation remain controversial but there is growing evidence indicating that sexual orientation is heavily influenced by prenatal biological mechanisms rather than by unidentified factors in post-natal socialization [ 3 ].

The concept favored here, despite dissent, is that homosexuality was and perhaps still is of kin survival value and is universally inherited as a chance variation [ 6 ]. The following quote is from a representative paper: "Notably, the combination of overconcernedness of the mother and detachment and hypercriticism of the father push the boy into avoidance of 'masculine' behavior, which in turn leading to a feeling of inferiority because the boy considers himself as lacking in manliness" [ 4 ].

If splitting occurs early in twin development each twin may develop his or her own sexual identity; splitting occurring later results in twins that have the twin sexual dispositions. A paradox is the occurrence of same-sex orientation in twins in that there is a higher level of concordance in monozygous twins compared to that in dizygous twins or non-twin siblings.

A possible process for such determination may be in the mitochondria, with universal maternal inheritance of a proportion of normal functioning but alternate mitochondria. Other theories that have been proposed include maternal stress during pregnancy and diminished testosterone in pregnancy and the neonatal period due to hyperprolactinemia [ 15 ].

A paradox is the occurrence of same-sex orientation in twins in that there is a higher level of concordance in monozygous twins compared to that in dizygous twins or non-twin siblings. Why do some identical twins have twin sexual orientations? Post-natal socialization theories, however, persist.

Human same-sex sexual orientation has occurred in all races and at all times since first recorded history [ 1 ]. Despite sharing the same DNA and usually the same upbringing, identical twins can diverge in sexuality. Official websites use.

They include various proposals that homosexuality results from problems in relationships with parents, especially the parent of the same sex, during childhood. The timing of embryonic splitting may be determined from the examination of fetal membranes, gay the concept of early fetal sexual orientation is open to support or disproval.

If sexual orientation was entirely genetically determined monozygous twins would be expected to have identical sexual inclinations. There is reason to believe that it has been present since our evolution as a species, even present in our hominid forebears [ 2 ].

Monozygous twins have twice the incidence of sexual concordance in comparison to dizygous twins but a third of these pairs have different sexual identities. An explanation for this disparity may lie in the time an embryo splits to form two separate fetuses.

Twining may occur when two separate ova are fertilized at the same time, resulting in dizygotic DZ or fraternal twins [ 7 ]. Are twins born into their sexual preferences and psychological orientation, or is sexuality fluid and molded by our environment?.

The proposals arise generally from a psychoanalytic tradition, based upon theories that are often not amenable to scientific testing. These twins may be of different genders; if both are of the same gender the incidence of concordant sexual identity is the same as for non-twin siblings [ 89 ].

Posted on 06/25/ by Kinsey Institute. These, along with others, appear to have faded and no longer appear in subject reviews. What role do genetic and environmental factors play in determining sexual identity concordance among identical twins?