The role of chromosomes in sex and gender

• Chromosomes - AO1

  - Found in nucleus of cells carrying information in the form of genes. The 23rd pair determines our sex
• The role of chromosomes - AO1

  - Made up of DNA

  - Genes short sections of DNA that code of charteristics in humans

  - 46 chromosomes arranged in 23 pairs

  - XX chromosomes - female - sperm carrying

  - XY chromosomes - male

  - Sex determined by sperm which fertilises the egg

  - Y chromosome on sperm carries gene called sex determining region Y (SDY)

  - Cause testes of develop in an XY embryo

  - Prosdes androgens - male sex hormones - cause the embryo to become male - without it embryo develops female.
• Hormones - AO1


  - Chemical subctance circulated in the blood that contros and regulates the activity of certain cells and organs.
• The role of hormones - AO1


  - Most gender development a result of hormones

  - In the womb hormones all for the development of reproductive organs

  - During puberty they develop secondary sexual characteristics

  - Males and females produce many of the same hormones but - in different concentrations

  - Male development - most important androgens - most known - testosterone
• Testosterone - AO1


  - A hormones from the androgen group mainly produced In male testes (a smaller amount in women's ovaries).

  - Associated with aggressiveness

  - Controls male sex organs

  - Develops at around 8 weeks of foetal development

  - Studies focus on the link between aggression and testosterone levels

  - Nanne Van de Poll et al - when female rates were injected with more testosterone, they became increasingly more aggressive
• Oestrogen - AO1


  - primary female hormone - important for menstrual cycle and reproductive system

  - Determines female sexual characteristics and menstruation.

  - Causes some women to experience heightened emotionality and irritability during the menstrual cycle. Pre-menstrual syndrome - PMS

  - PMS is sometimes been used as a defence for shoplifting and murder
• Oxytocin - AO1


  - A hormone which causes contractions in uterus during labour and stimulate lactation

  - Women produce it in larger amounts that men as a result of giving birth

  - Hormone stimulates lactation - breastfeed children

  - It reduces levels of stress hormones cortisol and facilitates bonding - known as 'love hormone'

  - Released in massive quatities during labour, and after child birth and allow mother to all in love with baby

  Men produce less - stereotype that they do not value intimacy and closeness

  Studies have shown both sexes produce it in similar amounts during kissing and intercourse
• Evidence supports the role of chromones and hormones - 😊

  - Influence of chromosomes on gender identity - supported by Dabbs et al - 1955

  - Offenders with the highest level of testorone were most likely to have committed violent and sexual related crimes

  - Van Gozen et al - 1995 - - Studied transgender individuals who were undergoing hormone treatment.

  - Transgender women showed decreases in aggression and visuospatial skills and transgender men showed the opposite

  Hormones do exert some influence on behaviour.
• Contradictory evidence - 🙁

  - Double blind study - Tricker et al - 1996 -

  - 43 men either given weekly injection of testorone or a placebo

  - No significant difference were found after ten weeks

  Slabbkoorn et al - (1999) - sex hormones have no significant effect on gender related behaviour

  - Many studies only involve small samples of unusual people or are conducted on animals - limiting meaningful generalisation
• Case of David Reimer - AO1 and AO3

  - Twin brothers Burce and Brian

  - Had a circumsion at 6 moths which Bruce without a penis

  Parents decided not to tell him and spent the rest of his life as a woman - Brenda

  - Had never adjected to life as female and when his parent told him he went back to living the life of a man - David

  - Experiencing sever psychological and emotional problems.
• Objections to pre-menstrual syndrome - 🙁

  - Many have questioned the effects of oestrogen on women's mood and object to a medical category of PMS as it stereotypes women's experience and emotions

  - Feminist critics claim PMS is a social construction not a biological fact - a way of privileging certain groups over others

  - Femisnts have pointed out the dismissal of women's anger based on biological terms.