- In every cell of the body there are 23 pairs of chromosomes which carry genetic codes that dictate our physical and behavioural characteristics. One of these pairs is called the sex chromosome which plays the role of determining the person’s sex. For females the chromosome pair is XX and for males it is XY, there is usually a direct link between an individual’s chromosome sex and their external genitalia. Initially there is no difference between foetuses that are genetically male and female as both contain an underdeveloped mullerian system.
- However, when the foetus is around 3 months old, the presence of the H-Y antigen causes the development of male genitalia whereas the lack of this antigen causes females to develop ovaries. Therefore explain how the role of genes determines how an individual acquires a particular sex. However gender development does not always follow this pattern, which can result in gender identity disorder.
- Nevertheless genes are not the only factor that can influence out gender. Hormones play a large part in gender development both prenatally and during adolescence as they influence the development of genitalia and our brain. Intersex individuals are those who receive abnormal levels of hormones prenatally. Genetically male embryos that are exposed to little male hormones, such as testosterone, may appear to have female genitalia at birth.
- This can also occur for genetically female embryos exposed to too much testosterone, resulting in ambiguous genitalia (Androgen Insensitivity Syndrome). Testosterone has also been found to affect brain development. It is suggested that the more testosterone a foetus is exposed to during its gestation, the more masculine their brain will be, in which they are less talkative and social but better at spatial navigation. If the brain of a genetic female is exposed to testosterone prenatally the effect may be a masculinised brain. This shows how hormones can influence both gender development and brain development.
+ The genes and hormones explanation of gender development has its strengths in the form of supporting evidence, for example the case study of David Reimer conducted by Money and Ehrhardt (1972). Reimer's penis was burnt off during a botched circumcision at the age of 6 months because of this his parents decided to nurture him as a girl, Brenda, with the intention of Brenda developing the gender identity of a female. Brenda however was not comfortable living as a female and on learning her true story she reverted back to her original gender as a male during her teenage years.
+ This case study supports the role of genes and hormones in gender development as despite being nurtured as a girl from 6 months he still felt like a boy suggesting biological sex is the primary factor in contribution to gender development. Furthermore the naturalistic setting of the study whereby he was brought up in his own home gives the study high ecological validity as it represents a real life scenario. This strengthens the validity of the study as the results has a high degree of realism which in turn strengthens the biological view on gender development because we can be sure genes and hormones play a crucial role in gender development in real life situations.
- However the genes and hormones explanation of gender development does have weaknesses due to methodological issues surrounding the supporting evidence. Firstly it is an idiographic case study meaning that the findings are only specific to the individual; David Reimer, this results in low population validity and because of this we cannot generalise the results found to the wider population as they may only be specific to that individual. One person cannot be representative of an entire population i.e. if a similar situation arose among others the same results may not be found which therefore limits the usefulness of the results found.
- This in turn means we cannot be sure that biological sex will be the primary factor in gender development for everybody. Others may be more susceptible to social influences and be content with whatever gender they are raised as so other factors aside from genes should still be considered when looking at gender development.
+ Conversely, there is more evidence to suggest that genes and hormones do play a significant part in gender development. A case study of the Batista family found that all 4 genetically male foetuses (XY) were born with external genitalia due to androgen insensitivity syndrome. They were raised as girls until puberty when testosterone level increased and their male genitalia began to develop therefore changing them into males. All girls accepted their sex change with relative ease which supports the biological approach, as despite being raised as girls the presence of male hormones meant they felt comfortable switching to become boys.
+ This would therefore suggest that biological factors such as hormones play a more significant role in gender development than social factors. As research into this area has given consistently similar results it can be argued that the explanation is high in external reliability. As such we can be sure that genetics and hormones are one of the main factors influencing gender development due to consistent support by researchers.
- However in order to accept the biological view of gender development we must accept the biological approach. This can be problematic because the biological approach is deterministic claiming your gender is pre-determined by your biology excluding social factors. When raising a child ethically you can never exclude social influences, therefore a cause and effect relationship between genes and hormones and gender can never be established. As a result it can never be proven that biology solely determines your gender so research into this area has no factual basis therefore weakening any biological explanation of gender development.
- When considering the role of genes and hormones play on gender development the nature-nurture debate should be considered. The nature side of the debate is supported by David Reimer as despite being raised as a girl from 6 months old he still felt like a boy inside. This implies that or nature/biology is more significant in gender development than social factors and the way you are nurtured.
- It would suggest that gender cannot be learned and that it has a purely biological basis, however the nurture side of the debate should also be considered. As the Batista family suffered from AIS they would have been prepared from a young age for the gender change so social factors could have also contributed to how easy the sex change was.
- This casts doubt upon whether gender development is solely a result of our biology and implies the way you are nurtured may also influence your gender. Therefore an interactionist approach would be most appropriate when explaining the relationship between genes and hormones and our gender development.