chromosomes and hormones

• role of chromosomes


  46 chromosomes in the human body, 23rd pair is the sex chromosomes. Female= XX, male= XY, babies sex is determined by the sperm that fertilises the ovum- sex-determining region on the Y chromosomes which produces androgens
• role of hormones


  prenatally in the womb, hormones act upon the brain development and cause the development of the reproductive organs. During puberty, a burst of hormonal activity triggers the development of secondary sexual characteristics. M+F produce the same hormones just at different levels.
• What is testosterone?


  It causes the development of male sex organs during foetal development. Can be linked to aggressive behaviour, small amounts of testosterone are produced in females
• What is oestrogen?


  predominantly produced by the ovaries and is responsible for the development and regulation of female reproductive systems. Key role in regulating the menstrual cycle, prepares the body for pregnancy. Causes physical changes, irritability and heightened emotionality, is linked to PMT and PMS
• What is oxytocin?


  The 'love' hormone, women produce larger quantities than men, as a result of giving birth. It stimulates lactation for breast feeding, reduces levels of cortisol and facilitates bonding. Male stereotype formed of being less intimate and close due to having lower levels of oxytocin.
• The case study of David Reimer


  • botched circumcision of twins
  • parents went to Money- gender neutrality, to help bruce adjust
  • bruce was raised as brenda in a stereotypically feminine way- played with dolls and wore girls clothes
  • brenda never really felt like they were a girl and was experiencing severe psychological and emotional problems
  • told about the gender reassignment - David became his name
  • committed suicide shortly after his twin in 2004
• Evaluation- evidence of testosterone


  +Christina Wang at al 2000, male hypogonadism- testosterone replacement improved sexual function, libido, mood and muscle strength. Supports the idea that gender is controlled predominantly by biological factors - acted more 'masculine'
• evaluation - social factors ignored


  -Hofstede et al 2010- gender roles are more about social norms than biology, collectivist vs individualist cultures. Doesn't show that gender is only about biological factors but also social factors have an effect so the theory may not be completely generalisable to all cultures.
• evaluation- reductionist


  -decounts that reduce gender, the level of chromosomes and hormones have been accused of ignoring or underplaying alternative explanations. Ignores that other factors like SLT, psychodynamic etc.
• evaluation- supporting evidence


  +/- David Reimer still felt like he was a male even though he was being told he wasn't and was treated his life as a female. This may have been due to the hormone levels in his body being different to that of a female. This shows biology has a huge impact on gender identity but it was a case study making the results ungeneralisable.