chromosomes and hormones

• Sex determining region of the Y chromosome


  Causes testes to develop in an XY embryo which produce androgens: male sex hormones. Typically, androgens cause the embryo to become a male, without them embryo will develop in a female
• Hormones


  • Influence gender development
  • Prenatally in the womb, hormones act upon brain development and cause development of reproductive organs
  • At puberty, a burst a hormonal activity triggers the development of secondary sexual characteristics such as pubic hair
• Testosterone


  • Male hormone which controls the development of male sex organs, which begins to be produced at around 8 weeks of foetal development
  • Influence on aggressive behaviour
• Oestrogen


  • Female hormone that determines female sexual characteristics and menstruation
  • Can cause heightened emotionality and irritability during menstrual cycle (PMS)
• Oxytocin


  • More produced in women
  • Stimulates lactation, making it possible for mothers to breastfeed their children
  • Reduces stress hormone cortisol and facilitates bonding
• Oxytocin is released in massive quantities during and after labour and makes new mothers feel 'in love' with their baby
• Evidence suggests that both sexes produce oxytocin in roughly equal amounts during amorous activities such as kissing or sexual intercourse
• David Reimer case


  • Born as Bruce, accidentally had his penis burnt off due to an electrical malfunction
  • Raised as a girl for the first years of life
  • Felt suicidal, changed back to living as a man, calling himself 'David'
  • Supports the role of chromosomes and hormones
• Dabbs et al - Offenders with the highest levels of testosterone were more likely to have committed violent or sexually motivated crimes
• Van goozen - Transgender women (male-to-female) showed decreases in aggression and visuo-spatial skills whilst transgender men (female-to-male) showed the opposite, when injected with hormones of other sex. suggests that sex does exert influence on gender related behaviours
• tricker et al - double blind study. 43 males. No significant differences in aggression were found after the ten-week period between the two groups given testosterone or placebo
• Objections to PMS


  • Questioned the effects of oestrogen levels on a woman's mood
  • Claim PMS is a social construction, not biological fact but a way of privileging certain groups over others
  • weakness as led to medicalisation- treated as medical conditions and dismissed womens emotions by biological terms
• chromosomes


  46 (23 pairs) of dna inside the nucleus of cells, chromosomes carry the genetic information that code for physical and behavioural characteristics
• chromosomes role in gender

  coding for different neuronal structures and hormone levels
• limitation of overemphasis of nature


  if don to biology- more differences in male and female behaviour than there actually are. other explanations (SLT) point to the importance of social context in the learning of out gender identity and gender role. social norms and cross cultural differences
• limitations of oversimplifying complex concept


  ignore other explanations - cognitive draws attention to a to the changing thought processes that underpin gender development.

  pyschodynamic approach point to the importance of childhood experiences such as interactions with the family