The Central Issue
There are a number of important issues that underlie the modern understanding of transgenderism and how society
deals with it. These include causes of the condition, how we distinguish "male" from "female" and the
nature of congenital intersex conditions in which the usual male-female "rules" are broken.
The causes of transgenderism are not fully understood. However there is growing evidence that the
transgendered conditions is due to a person's nature
rather than the nurture
early in life. The early environment of transgendered people are just as varied as the wider population.
There are no significant causal links relating conditions of early environment, such as absent fathers, with
the transgender condition. Instead biological conditions appear to hold the key to the later onset of the condition.
- Pre-natal evidence.
An important clue to its biological origin is given by a recent study of the ratio of finger lengths.
The study found that in transwomen the ratio of the lengths of the second and fourth fingers is
comparable to that of genetic women and higher than that of genetic males .
This ratio is known to be directly related to prenatal hormone exposure and so it appears that
transwomen had a lower exposure to androgens as fetuses.
- Other biological links. Other studies find brain physiology is related
to the target gender in transgendered people.
A study in 1995 examined the brains of many individuals including six transwomen .
The study found that a tiny part of the brain known as the central subdivision of the bed nucleus
of the stria terminalis (BSTc) is larger in men than in women. They also found that the BSTc of
the six transwomen was as
small as that of women generally. It is not known if the size of the BSTc is altered by hormone therapy.
Nevertheless, this study does provide evidence the brains of the transwomen appear to coincide with their
conviction that they are women, at least after transitioning.
A more-recent study measured the total brain and the hypothalamus volumes of transgendered people before and during
hormonal therapy . The study found that the brain volumes are changed by the hormone therapy towards the
proportions of the targeted gender.
 H.J. Schneider, J. Pickel, G.K. Stalla, Typical female 2nd-4th finger length (2D:4D)
ratios in male-to-female transsexuals-possible implications for prenatal androgen exposure,
International Society of Psychoneuroendocrinology 31 265-269 (2006).
 J.N. Zhou, M.A. Hofman, L.J. Gooren and D.F.A. Swaab, Sex difference in the human brain and
its relation to transsexuality, Nature 378, 68-70 (1995).
 H.E. Hulshoff Pol, P.T. Cohen-Kettenis1, N.E.M Van Haren,
J.S. Peper, R.G.H. Brans, W. Cahn, H.G. Schnack, L.J. Gooren and R.S. Kahn
Changing your sex changes your brain: influences of
testosterone and estrogen on adult human brain structure, European Journal of
Endocrinology 155 107-114 (2006)].
Indicators of "male" and "female"
There are three quite different properties that indicate if a person is male or female.
- The sex chromosomes indicate whether a person is
genetically male or female. Genetic males have XY chromosomes
and genetic females have XX chromosomes.
- The anatomical sex characteristics of the body are also used as an indicator.
Anatomical males have male
genitalia and anatomical females have female genitalia.
- The gender identity of a person is also another indicator of
whether the person is male or female.
Usually all three indicators are in agreement. For example, a person with XX chromosomes will usually have female
genitalia and a female gender identity. However, this correspondence between the three indicators is not
always the case. People with intersexuality
can have ambiguous genitalia and genitalia that does not
match their sex chromosomes.
There are a number of intersex conditions where the sex chromosome
does not match the anatomical
of the person. The following two illustrate how nature can sometimes deviate from the rule
- Androgen insensitivity syndrome - genetic XY with female
Androgens is the generic name of the male hormones which includes testosterone.
People with androgen insensitivity syndrome (AIS) are genetically male (with a XY chromosome) but have
female genitalia and a feminine appearance. The insensitivity to androgens means that their body doesn't develop
in a typically
masculine way. AIS people have a vagina but lack a uterus and ovaries and they have undescended testes.
A person with complete AIS typically identifies as female. She may be unaware of her AIS condition.
- Congenital adrenal hyperplasia - genetic XX with male anatomy
This condition is the like AIS but for genetic females (with a XX chromosome). It is a genetic disorder in which
the adrenal glands produce a high level of masculinizing hormones instead of cortisone. Typically the person
develops male characteristics including a deep voice and dense body hair
and has male genitalia, although in some cases the genitalia is ambiguous.
Summing up the Central Issue
In intersexuality the genetic and anatomical male-female indicators disagree. This leaves intersexed
people with the question of which social gender role they should follow. Ultimately, however, it is
their inherent gender identity that is the deciding factor in the decision. It is only by
following a role in accord with their gender identity can they hope to achieve contentment. The
male-female ambiguity in intersexuality allows an intersexed person to justify either gender identity
and thus living in either gender role. In cases where their anatomy is not in sufficient accord with
their gender identity intersexed people are given the opportunity to make appropriate changes.
In people who are transgendered, the absence of anatomical abnormalities does not lesson the status of
the person's gender identity as being central to deciding the appropriate social gender role.
In this context, transgendered people are no different from people with intersexuality. It follows that
transgendered people should also be given the option of altering their anatomy to match their identity.