Discuss the role of hormones and/or genes in gender development. (8 + 16 marks)
Biological sex is determined by genes, which are on chromosomes. Humans generally have 23 pairs of chromosomes, one pair of which determines sex. Females have an XX pair while males have an XY pair. Chromosomal sex largely controls how masculine or feminine the egg's development will be.
Chromosomal sex controls whether an embryo will develop ovaries or testes. The SRY gene on the Y chromosome which only males possess will cause the gonad (the organ which produces sex cells) to develop into testes; a female's gonad will develop into ovaries due to the absence of the SRY gene. External genitalia strongly ...view middle of the document...
This suggests that testosterone makes the brain more masculine. However, the relationship may not be causal as correlation does not imply causation: for example, testosterone may affect the levels of other hormones which may affect maternal personality.
However, there is evidence that biological sex is not the main factor in gender development. Money and Ehrhardt claimed that the sex that the child is reared as is more important than their chromosomal sex. They believed that intersex individuals could be successfully raised as either a girl or a boy, and that biological males could be raised as girls & biological females could be raised as boys.
Money's theory, however, has been disputed by the case of David Reimer, who was genetically male but was raised as a girl (under Money's recommendation) after a botched circumcision. Despite being given hormone treatments in order to develop an outwardly female appearance, Reimer became isolated and depressed, and reverted back to being male immediately after finding out his true sex. This suggests that chromosomal sex is crucial to gender development, conflicting with Money's claims.
This outcome has also been supported by further research. Reiner & Gearhart studied 16 biological males born with almost no penis. Of the 14 who were raised female, 8 re-assigned themselves as male by the age of 16. This high rate suggests that biological factors have a key role in gender development.
However, there are methodological problems with the two aforementioned studies and many other studies in this area. The case of Bruce Reimer is a...