Brain sex theory suggests that GID is caused by specific brain structures that are incompatible with a person’s biological sex. Particular attention has been paid to those areas of the brain that are dimorphic, in other words, take a different form in males and females. Zhou et al (1955) studied the bed nucleus of the stria terminalis (BSTc) which is around 40% larger in males than it is in females. Post mortem studies of 6 male to female transgender individuals found that the BSTc was found to be a similar size to what would be expected in a typical female brain.
There is evidence that there may be a genetic basis to GID. Heylens et al (2002) compared 23 MZ twin pairs with 21 DZ twin pairs, where one of each pair had been diagnosed with GID. They found that 9 of the MZ twins (39%) were concordant (i.e. both twins with diagnosed with GID), whereas none of the DZ twins were, supporting the view that there is a genetic basis to GID
Evaluation of the biological explanation of GID
It is claimed that the BSTc is fully formed at the age of 5, and therefore cannot be affected by hormone treatment that the transgender person may be given as part of their transgender therapy. If this is true, then it would support the view that the BSTc plays a causal role in GID. However, Pol et al (2006) found that transgender hormone therapy did affect the size of the BSTc. This means that we cannot rule out the possibility that the size of the BSTc is a result of treatment, rather than being the cause of the condition.
Validity of the research
Twin studies only partially support a genetic link in GID. This is because the concordance rate is much below 100% for MZ twins (39% in Heylens’ study), therefore it suggests that even if there is a genetic element to GID, there must be other environmental factors involved for the condition to be triggered. Also, the research typically involves very small samples, so generalisation is an issue
The explanation attempts to reduce GID to simple biological factors, which is probably too simplistic a view to allow us to fully understand the origins of GID. There is no account taken of how environmental, social or cultural factors may play a part. The fact that incidence of GID has increased in recent years would suggest a social/cultural element. Therefore, the interactionist approach (considering a range of different factors) is probably a more realistic
Social psychological explanations The psychoanalytic explanation argues that GID in males is caused by extreme separation anxiety before gender identity has been established. The child fantasises about a symbiotic fusion with his mother to relieve the anxiety, and thus the danger of separation is removed. The consequence is that the child becomes his mother, and in doing so, adopts a female gender identity.
Social explanations would suggest that GID is learned in the environment through, for example, operant conditioning. This would suggest that GID individuals have been positively reinforced for cross-gender behaviour. Many young children experiment with gender roles, e.g. a young boy dressing up in his mum’s clothes, and learning theory argues that parents of gender dysphorics may have reinforced the condition by encouraging and complimenting their children for such behaviour. Social learning theory could also play a part, as children may imitate cross-gender behaviour they observe in the environment, which then becomes internalised and incorporated into the child’s identity.
Evaluation of social psychological theories of GID
Stoller (1973) reported that in interviews with GID males, they were seen to display overly close mother-son relationships that would lead to greater levels of female identification and confused gender identity, supporting the psychoanalytical explanation.
Rekers (1995) reported that in 70 gender dysphoric boys there was more evidence of social than biological factors, and there was a common factor of a lack of stereotypica male role model, supporting the view that social learning factors play a role in the condition
Zucker et al (2008) performed a longitudinal study on gender-dysphoric females between two and three years of age who had been referred to a clinic. Only 12% were still gender dysphoric at age 18. An equivalent study on males found that only 20% were still gender dysphoric as adults. This supports a social environmental basis to GID, as if genetic or neuroanatomical factors were the cause, we would not expect the effects to be transient.
The psychoanalytic explanation does not offer an adequate explanation of GID in females. In addition, Rekers research suggests that gender disturbance in boys is more likely to be associated with the absence of the father, rather than fear of separation from the mother. Furthermore, the assumption that GID is caused by separation anxiety is very hard to test. The fantasies that trigger the condition are thought to exist at an unconscious level and are therefore inaccessible to the conscious mind. This means that evidence is limited and the theory is little more than speculation.
Doesn’t account for biological factors
Increasingly, evidence suggests that the influences of hormones and genetics is the main cause of GID, but there is little evidence to suggest a totally biological explanation. Therefore, social psychological explanations of GID may be useful in understanding the factors that contribute towards the development of GID, but are unlikely to be sufficient as a stand alone explanation