biological explanations/atypical chromosomes

• • CAH - how does this support the role of hormones in gender identity:
  • The xx biological females have higher masculine traits such as aggression even though they have xx chromosomes - suggesting the higher levels of testosterone can influence male gendered behaviours 
• Supporting evidence for the role of genetics in gender identity:

  • Case study: Biological male twins, one of the boys had their penis cut off at a very young age, parents then raised him as a girl (Brenda) recommended by a psychologist who believed that gender was more influenced by environment, however he never adjusted to life as a female and once he found out the truth, converted back to being male 
• role of chromosomes in gender identity:

  • Y chromosome has a sex determining region y gene (SRY gene) 
  • This gene produces androgens - cause embryo to become male
  • This means testes develop in an xy embryo
• kleinfelters syndrome: occurs in biological males, they have chromosomes XXY. The extra X chromosome leads to increased oestrogen. They have reduced body hair and poor language and reading skills.
• Turner’s syndrome: occurs in biological females who have chromosomes XO, they’re missing the second X chromosome. They have no menstrual cycle and tend to have higher than average reading abilities and also look physically immature as well as acting immature
• Kleinfelters and Turner’s syndrome are evidence to support the role of chromosomes in gender development
• The typical sex chromosome pattern for males is XY and for females, is XX. However, atypical sex chromosome patterns can result in Klinefelter’s Syndrome for males, and Turner’s Syndrome for females.
• Hormones:

  • Chromosomes initially determine sex and therefore the quantities of different hormones such as testosterone and oestrogen
  • In the womb hormones encourage development of reproductive organs and also areas of the brain, e.g- testosterone helps develop the sexually dimorphic nucleus and areas associates with spatial awareness 
  • Males and females have the same types of hormones but in different concentrations 

  Sex hormones:

  • Testosterone- male sex hormone (androgen) - often linked with aggression 
  • Oestrogen- female sex hormone - often linked with being highly emotional
  • Oxytocin- love hormone - peaks in women around childbirth- leads to nurturing behaviours