Gender Dysphoria or Gender Identity Disorder {GID - the psychiatric classification of such dysphoria} is generally defined as the condition of feeling one's emotional and psychological identity as male or female to be opposite to one's biological sex.
In terms of the history of psychology, gender dysphoria is a relatively new concept being observed and studied. One key perspective is the biosocial one.
The biosocial approach to gender dysphoria suggests that this condition develops because of an interaction between biological and psychological factors, a kind of diathesis-stress approach where a person is born with some biological difference {such as genes} which increases the likelihood of gender dysphoria. However, life events determine whether such a predisposition ultimately develops into dysphoria.
Such a biological predisposition might include brain differences. For example, brain-sex theory is based on the fact that male and female brains are different and perhaps transsexuals' brains do not match their genetic sex. Two Dutch studies found that the number of neurons in the BSTc {located in the thalamus} in MtF transsexuals was similar to that of females. Furthermore, the number of neurons in FtM transsexuals was found to be in the male range.
Biological predisposition might include exposure to pesticides. For example, the insecticide DDT contains oestrogens which may mean that males in the womb that are prenatally exposed to unduly high levels of female hormones may end up with a mismatch between genetic sex and hormone influences.
Psychosocial factors enhance the expression of the underlying biological factors. This might include mental illnesses - for example, Coates et al proposed that a boy {his case study} who developed Gender Identity Disorder did so as a defensive reaction to his mother's depression following an abortion. They suggested that the trauma may have led to a cross-gender fantasy as a means of resolving the ensuing anxiety.
Support for brain-sex theory comes from Rametti et al who studied the brains of FtM transsexuals before they started transgender hormone therapy. They found that these individuals had more similar white matter patterns to people who shared their genetic identity {males} than those who shared their biological sex {females}. This shows that the biology of the brain must have some significance in the development of gender dysphoria.
Further support for the biological aspect of the biosocial approach comes from Vreugdenhil et al who found that boys born to mothers who were exposed to dioxins {which promote oestrogen} displayed feminised play. This shows that exposure to chemicals may prenatally predispose certain individuals to be gender dysphoric and suggests that external biological factors may also influence the development of gender dysphoria.
However, a criticism of the biosocial approach comes from Cole et al who found that the range of psychiatric conditions displayed in 435 dysphoric individuals was no greater than a "normal" population. This shows that psychological conditions may not be important in the development of gender dysphoria and suggests that such dysphoria is generally unrelated to trauma or pathological families.
Further criticism of the biosocial approach comes from recent research carried out by neuroscientists {Tel Aviv University, 2015} who have found that there is actually no difference between a "male" and "female" brain. They looked at the differences between 1400 brain scans from people of both genders aged 13-85 and found that very few people had all of the brain features they might be expected to have based on their sex - across the sample, between 0 and 8% had "all-male" or "all-female" brains. This research shows that gender is non-binary and so decreases support for the biological part of the biosocial approach as it suggests that biology doesn't influence sex-typed behaviour as much as we traditionally thought - and perhaps gender dysphoria is just socially constructed. It's also worth noting the increase in dysphoria-related incidents for nonbinary identities, which research doesn't account for.
Furthermore, research on gender dysphoria is ethically socially sensitive because it has potential social consequences for the transsexuals represented by the research, which raises the question of whether these people would be better of without this research. For example, if a biological cause for gender dysphoria is identifies, it may lead to society becoming more accepting of transsexuals as it is "not their fault" that they are dysphoric, but this identification may also lead to people thinking that transsexualism is inevitable which has the potential to harm such people. Evidence of this comes from Congenital Adrenal Hypoplasia {CAH} cases, which prove that a simple cause and effect relationship is unlikely. This suggests that research concerning the biosocial approach has to be conducted carefully to make the implications beneficial to those who are more vulnerable to developing gender dysphoria.
It is safe to say that acceptance of transgender identities, within the binary, has indeed become more common in society, with the majority of people supporting such individuals - but there still is a long way to go. Celebrity cases such as Caitlyn Jenner warrant much-needed media attention, but some people find it hard to change or mould their beliefs, particularly from a cultural perspective. We hope to help change that.
Although this is an area that is starting to get more psychological attention, it is still massively understudied and there is lots we don't know. It's time people understood the complexity of gender and more work should be done by academic disciplines to help society do so.