Discuss the role of hormones and/or genes in gender development (8 marks + 16 marks)

Discuss the role of hormones and/or genes in gender development (8 marks + 16 marks)

Each individual has 23 chromosomes which contain hundreds of genes containing instructions on physical and behavioural characteristics such as eye colour. One pair of these chromosomes are called the sex chromosomes because they determine the biological sex of the individual. It can be either ** (female) or XY (male).

There is a link between chromosomal sex and internal and external genitalia. During prenatal development all individuals start out the same regardless of gender; both seem female. However when the foetus is 3 months old, if it has the chromosomal sex of XY it would be exposed to testosterone which would make the external genitalia (penis) develop.

Research suggesting that biological sex is not the main factor in gender development comes from John Money. This was the case study on David Reimer whose penis was accidentally removed when he was born. Money argued that sex of rearing was more important and said that David could successfully be raised as either a girl or a boy. David was raised as a girl whilst his twin brother was raised as a boy (control). Money later claimed that the gender assignment has been a success.

 However, throughout childhood, David (his female name was Brenda) has struggled with his identity. His parents decided to tell him/her the true story, and in result he immediately reverted to his true sex (male). This challenges Money’s claims and suggests that biological factors such as genes play a key role in gender development (biological determinism).

Further research which supports the role of biology comes from Reiner and Gearhart. They studied 16 genetic males born with no penis. Two were raised as males and remained males, whereas 14 were raised as females and 8 of them re-assigned themselves as males by the age of 16. This further supports the view that biological factors play a key role in gender development.

The roles of hormones in gender development can affect the development of external genitalia and the brain, both of which influence gender behaviour. The role of hormones can be seen when studying…