Chromosomes and Hormones

• influence of chromosomes on gender

  • The biological explanation of gender emphasises the importance of conception since this is where the chromosomes of a child are determined. For example, if an egg carrying an X chromosome is fertilised by a sperm carrying an X chromosome, then the child will be genetically female (XX); however, if a sperm carrying a Y chromosome fertilises the egg (always carrying an X chromosome) then the child will be genetically male (XY).
• influence of hormones on gender

  • Oestrogen: female hormone and responsible for development of female reproductive systems
  • Testosterone: produced by the gonads to inform the foetus to take on male characteristics such as aggression and competitiveness
  • Oxytocin: crucial in childbirth, nurturing and regulating emotions such as stress.
• evaluation of biological explanation of sex and gender development (1)

  • research support it has gathered. Young (1966) manipulated the amount of testosterone exposed to unborn baby rats and found that the female offspring were born masculinised. The masculinised female offspring played more aggressively, had an increased size in the SND, and they demonstrated more exploratory behaviour, in contrast to female offspring who were not exposed to more testosterone in utero. This provides support for the claim that hormones and physiology are highly influential in gender development.
• influence of brain on gender

  • the size of the suprachiasmatic nucleus (SDN): an area associated with our psychological gender identity. The hormone testosterone is implicated in the size of the SDN and therefore the SDN is approximately 2.5 times bigger in genetic males than in genetic females. This difference in biology contributes to the psychological gender identity, as well as some psychological gender differences
• evaluation of biological explanations on gender development (2)

  • Money (1967) aimed to support his hypothesis that children's gender is the result of nurture rather than biology. His case study on Bruce Reimer, a genetic male who was raised as a girl, was used to investigate this hypothesis. Bruce did not identify as a female and in adult life, reversed the surgery and continued to live as a male. This case study provides crucial support for the biological explanation of gender, and disputes contrasting theories about gender being neutral at birth and influenced by nurture.
• evaluation of biological explanation on gender development (3)

  • One limitation of the biological approach of gender is the oversimplification of hormones. The approach proposes that there are distinct male hormones (testosterone) and female hormones (oestrogen) however, many argue that this is a very simplified view of hormones. Both of these hormones are found in men and women in different concentrations and are not isolated to each gender, which the biological approach appears to suggest. Therefore, the endocrine system involved in gender identity is more complex than initially proposed.
• evaluation of biological explanations on gender development (4)

  • biologically reductionist: assumes that this complex psychological and physiological part of our identity can be broken down to the lowest level of explanation - genes and hormones. As a consequence, the theory ignores the roles of any nurturing influences such as culture or media. This makes it incredibly hard to disentangle nature and nurture influences, concluding that the biological theory of gender should acknowledge a broader, more holistic view of gender.
• evaluation of biological explanations on gender development (5)

  • biologically deterministic: theory considers gender to be a fixed part of our identity and not flexible at all. This rigid view of gender suggests that there is no room for free will or control in our gender identity, which can be argued to be socially sensitive. Since gender identity is no longer restricted to ‘male’ and ‘female’ sex categories, this theory would fail to accommodate the fluidity of gender and may reinforce stereotypical and outdated views in society that no such other sex categories exist.