(Original post by brightonlad89)
Sex (and the determiniation of) has come some
way in these past few decades (babies are no longer not sexed as male if their penis is not considered to be large enough for future copulation), however it still is very phallic-centric (a boy is a baby with a penis, a girl is a baby with the absence of a penis), when actually, the primary sex determination is that of the brain.
Of course, science is not advanced for us to cross-check all sex identifiers in babies before announcing their sex and so genital determination is still necessary. However, anomolies do occur (more often than one would think) due to sex identifiers such as chromosomes, genitalia, internal sexual organs, brain sex etc. not complementing each other.
The brain is the primary sex identifier (refer to the Joan/John case of the boy who had his penis accidentally destroyed during a circumcision and was raised as a girl. Unaware of his circumstances, he still strongly identified in the male sex role. Similar to transsexual male children.)
Genitals have, effectively, no influence on one's sex role (other than heavily influencing how one is raised as a child). This complements most children, but for those whose brain sex differs from what their genitalia imply, this causes confusion but, their brain sex is still dominant even if in a repressed state. For example, if a woman lost her clitoris and vagina in some freak accident, she would still be a woman. Although the majority of the time the genitals are a good indicator of sex, the brain ultimately is primary with the body as secondary.
You are right that is is likely to be the brain that developed as the 'wrong' sex than the body (as chromsomes and genitals in transsexual people usually are complementary), because the brain is the primary indicator I believe it is more appropriate to view the genitals and social role as the issue and therefore treat it as other biological/physical conditions.
The stigma attached to mental illness is severe, and this is part of the problem in the case of G.I.D. You are also right that transsexual people often appear to use negative terminology towards mental disorders and this is likely due to a desire to distance themselves from it as much as possible. Stigma towards mental illness does need to be addressed and I hope one day it will diminish completely. But, even in an ideal world where mental illness was not stigmatised, I still believe the connotations of transsexuality would still cause misconceptions about the condition and therefore is not an appropriate classification for the well-being of the service users.