“Describe the role of genes and hormones in gender development”
Biological sex is determined by chromosomes in your genes. At prenatal development, only a few weeks after conception, there is no notable difference between male and female structure until the Gonadal Ridges, the structure which develops either female or male sex organs, grows to determine the sex of the baby. All prenatal babies have genitalia that appears distinctly feminine until at three months, hormones- testosterone if the baby’s to be a boy, and oestrogen if the baby’s to be a girl- is released and the baby develops into the hormone determined gender. For these reasons it is believed that there is a direct link between chromosomes and sex, and therefore sex and gender behaviour.
Biology can be used to explain a person’s gender using hormones and genes as a reason for gender behaviour, because hormones influence both genitalia and brain development which then influence the development of gender behaviour. This could explain why some girls and women become tom boys, perhaps due to too much exposure to testosterone during pre natal and adolescent development which masculinises the brain so that they display male gender behaviour; meaning a female may display the more masculine trait of spatial skills as the testosterone acts on this cerebral of the brain. A supporting hypothesis for this theory is Geswind & Galaburda (1987) who were the first to propose that sex differences are caused by the effects of testosterone levels on a developing brain. Research by Deady et al has demonstrated that this hypothesis may be correct; he found that high levels of salivary testosterone in biological females were linked with low scores of maternal personality. This study helps in supporting that hormones have a great influence on the development of gender behaviour, and that certain hormones can determine gender traits.
This approach to gender development sits on the nature side of the nature vs. nurture debate, in that it believes that nature –through genes and hormones- has a greater effect on the development of gender behaviour. The case of David Reimer (started in 1965, a longitudinal case study) can be used to support this as during a circumcision the boy’s physical masculinity (his
male genitalia) was burnt off and his mother and Dr Money made the decision to raise David as a girl with the strict instruction to never let Brenda find out. All throughout his childhood David Reimer- named Brenda- played with her brothers toys instead and behaved predominantly male, despite Money’s and his mothers attempts to femininize his behaviours. At adolescence Reimer was pressured by Money to undergo vaginal construction where Money used methods to reassure him which David/ Brenda found distressing. At this stage it was revealed to Brenda that he was in fact male, and the boy went on to live as a male; showing that nature has a big role in gender development as David denied his female nurturing and instead grew into the role of a male quite naturally. We can criticise this study for its unethical approach to trying to turn David into a female, as Money used tactics that were both shocking and unethical, by making Brenda and her brother strip so that Brenda could understand that she was a female. It can also be criticised because Money claimed that biological sex was not the main factor of gender development despite the evidence of the Reimer case. Due to it being a case study, we can not generalise the results to every child because of this methodological issue.
However, it is still argued that biological factors may not be the most important, other factors are still key. An example is Dessens et al’s study of 250 genetic females who were prenatally exposed to high levels of androgens (male hormones) but still raised female. Only 5% of these females experienced gender dysphoria- which shows that other factors are important in gender development and that hormones weren’t a key factor of determining gender in this study. This criticism of the biological approach shows that it is too reductionist, in that it ignores other factors. As well it is deterministic, as it reduces human behaviour down to simply biology and the act of hormones on gender development, ignoring social and cultural influence.
Research produced from studies into biological effects of gender has been used in real life application. Until 1991 it was ruled that people with XX chromosomes had to compete in female events within the Olympics, and people with XY chromosomes had to compete in male events, but research into gender
development changed the rules and now it genetic sex no longer determines entry into the Olympic; proving that research into this field has been most valuable for real life application.