Editing Gender dysphoria (section)

== Causes ==
{{See also|Causes of gender incongruence}}

In a 2020 position statement, the [[Endocrine Society]] stated that in the late 20th century, transgender and gender incongruent people were thought to suffer a mental health disorder and gender identity was considered malleable and subject to external influences. But that this was no longer considered valid as "Considerable scientific evidence has emerged demonstrating a durable biological element underlying gender identity. Individuals may make choices due to other factors in their lives, but there do not seem to be external forces that genuinely cause individuals to change gender identity".<ref name="endocrine-society-2020"/>

The cited evidence includes that attempts to change the gender identity of intersex patients to match their genitalia or chromosomes are generally unsuccessful, that there is evidence that higher levels of exposure to androgens in utero causes higher rates of male gender identity among those with female chromosomes, that those with [[complete androgen insensitivity syndrome]] among those with male chromosomes typically have a female gender identity, that identical twins are more likely to both be transgender than non-identical twins, and that brain scans have shown associations with gender identity rather than genitalia or chromosomes.<ref name="endocrine-society-2020"/>

Their 2017 clinical practice guidelines stated "Results of studies from a variety of biomedical disciplines—genetic, endocrine, and neuroanatomic—support the concept that gender identity and/or gender expression likely reflect a complex interplay of biological, environmental, and cultural factors" and noted research pointing to unique brain phenotype associated with gender dysphoria and gender incongruence, heritability of the conditions, the role of pre- and post-natal androgens in gender development, and gender identities among intersex people.<ref name="Hembree"/>