Over time various theories have
been put forward attempting to explain the
origin of transsexualism in terms of nature,
nurture or a combination of both.
The most compelling evidence points to a
biological multifactorial cause based in the
development of the brain where a human
being’s sexual identity develops in brain
differentiation to male or female sex, in the
same way as the other sexually differentiated
features of the body, being fixed and
unalterable by the completion of infancy at the
latest (Zhou et al., 1995; Kruijver et al.,
2000).
Professor Louis Gooren, an endocrinologist
and Chair of the only Faculty of Transsexualism
in the world, a part of the Free University of
Amsterdam and its teaching hospital, said in
1993:
"It has always been
assumed that the sexual differentiation was
completed with the formation of the external
genitalia. But it is NOT.
Since the beginning of
this century we have known that the brain, too,
undergoes a sexual differentiation… It is
likely from the available evidence that in
transsexuals the pattern of sexual
differentiation of the brain has not followed
the pattern typical of that sex: in other words,
the nature of the chromosomes, the gonadal and
genital development are in contradiction with
the brain sex."
Causes for transsexualism
