"A major issue of debate in our country is whether a man who says he is a woman can use the ladies bathroom or not "
We should limit it to men whose doctors say they are women, and vice versa.
"When the DNA says you are male then you are a male. When the DNA says you are female then you are a female. "
The study of the causes of transsexuality investigates gender identity formation of transgender people, especially those who are transsexual. Transsexual people have a gender identity that does not match their assigned sex, often resulting in gender dysphoria. [1] The causes of transsexuality have been studied for decades.
The most studied factors are biological. Studies beginning with Zhou in 1995 have found that trans women's brain structure (volume and density of neurons) is similar to cisgender (cis) women's and unlike cis men's, and trans men's is similar to cis men's, even when controlling for hormone use. A 2002 study by Chung suggested significant sexual dimorphism in the BSTc did not become established until adulthood, theorizing that either changes in fetal hormone levels produce changes in BSTc synaptic density and other factors which later lead to the observed differences in BSTc, or the differences are affected by the generation of a gender identity inconsistent with assigned sex. Studies in 2004 (Swaab), 2006 (Gooran), 2008 (Garcia-Falgueras), and 2010 (Rametti) confirmed earlier research finding that gender identity is influenced by brain structure. (Brain structure differences have also been noted between gay and heterosexual men, and lesbian and heterosexual women as part of extensive research on biology and sexual orientation.) Studies have also found that both androphilic and gynephilic trans women's brain function and responses are like cis women's and unlike cis men's, or are intermediate between the two. Likewise, studies such as Rametti's have found that trans men have male-like white matter patterns (even before using hormones), regardless of sexual orientation.
With regard to genetic factors, a study by Hare reported that trans women have a longer androgen receptor gene than cis men, which is less effective at binding testosterone, potentially preventing complete masculinization of the brain. (Prenatal androgen exposure or sensitivity, or lack thereof, is an often cited mechanism to explain observed brain-structure differences.) A study by Bentz found that trans men have a CYP17 allele distribution like cis men and unlike cis women. [2] A twin study found that 33% of pairs of identical twins were both trans, compared to only 2.6% of non-identical twins who were raised in the same family at the same time, but were not genetically identical. [3]
Psychological factors have also been proposed. The failure of an attempt to raise David Reimer from infancy through adolescence as a girl after his genitals were accidentally mutilated is cited as disproving the theory that gender identity is determined by parenting. Ray Blanchard developed a taxonomy of male-to-female transsexuality that assumes transsexuals are either homosexual or autogynephilic, but it is controversial; J. Michael Bailey, Anne Lawrence, James Cantor and others support it, but Charles Allen Moser, Larry Nuttbrock, Julia Serano, the World Professional Association for Transgender Health and others argue it is poorly representative, non-instructive, and lacks empirical evidence, because the experiments behind it are poorly controlled and/or contradicted by other data.
The study of the causes of transsexuality investigates gender identity formation of transgender people, especially those who are transsexual. Transsexual people have a gender identity that does not match their assigned sex, often resulting in gender dysphoria. [1] The causes of transsexuality have been studied for decades.
The most studied factors are biological. Studies beginning with Zhou in 1995 have found that trans women's brain structure (volume and density of neurons) is similar to cisgender (cis) women's and unlike cis men's, and trans men's is similar to cis men's, even when controlling for hormone use. A 2002 study by Chung suggested significant sexual dimorphism in the BSTc did not become established until adulthood, theorizing that either changes in fetal hormone levels produce changes in BSTc synaptic density and other factors which later lead to the observed differences in BSTc, or the differences are affected by the generation of a gender identity inconsistent with assigned sex. Studies in 2004 (Swaab), 2006 (Gooran), 2008 (Garcia-Falgueras), and 2010 (Rametti) confirmed earlier research finding that gender identity is influenced by brain structure. (Brain structure differences have also been noted between gay and heterosexual men, and lesbian and heterosexual women as part of extensive research on biology and sexual orientation.) Studies have also found that both androphilic and gynephilic trans women's brain function and responses are like cis women's and unlike cis men's, or are intermediate between the two. Likewise, studies such as Rametti's have found that trans men have male-like white matter patterns (even before using hormones), regardless of sexual orientation.
With regard to genetic factors, a study by Hare reported that trans women have a longer androgen receptor gene than cis men, which is less effective at binding testosterone, potentially preventing complete masculinization of the brain. (Prenatal androgen exposure or sensitivity, or lack thereof, is an often cited mechanism to explain observed brain-structure differences.) A study by Bentz found that trans men have a CYP17 allele distribution like cis men and unlike cis women. [2] A twin study found that 33% of pairs of identical twins were both trans, compared to only 2.6% of non-identical twins who were raised in the same family at the same time, but were not genetically identical. [3]
Psychological factors have also been proposed. The failure of an attempt to raise David Reimer from infancy through adolescence as a girl after his genitals were accidentally mutilated is cited as disproving the theory that gender identity is determined by parenting. Ray Blanchard developed a taxonomy of male-to-female transsexuality that assumes transsexuals are either homosexual or autogynephilic, but it is controversial; J. Michael Bailey, Anne Lawrence, James Cantor and others support it, but Charles Allen Moser, Larry Nuttbrock, Julia Serano, the World Professional Association for Transgender Health and others argue it is poorly representative, non-instructive, and lacks empirical evidence, because the experiments behind it are poorly controlled and/or contradicted by other data. |
