Role of Chromosomes & Hormones

• XX Chromosome

  Female
• XY Chromosome

  Male
• What is the typical chromosome pattern in gender development

  1. Foetus is either XX or XY in the Womb
  2. Until 6 weeks external genitalia look female (identical gonads)
  3. At 12 weeks, if foetus is male the gonads become testes and produce testosterone, which causes their external genitalia to develop into a penis
  4. testosterone also affects the brain and behaviour at this stage
  5. The Y chromosome triggers the development of the testes
• What is Testosterone?

  A steroid hormone that stimulates male secondary sexual characteristics
• What is the role of Testosterone in gender development?

  • Affects brain development prenatally & later in childhood (during puberty)
  • Immediately after birth, boys have a surge in Testosterone which causes the sex organs to develop & impacts the hypothalamus in the brain
  • Impacts brain areas linked to spatial skills, competitiveness & aggression
  • Surges in testosterone during puberty responsible for secondary sexual characteristics in males - deeper voice, facial hair etc
• What is Oestrogen?

  A group of steroid hormones which promotes the development and maintenance of female characteristics in the body (secondary sexual characteristic)
• Oestrogen does not affect the foetus in the womb

  • Females do not need hormones to direct prenatal genital development
• Role of Oestrogen in gender development

  • Puberty onwards- menstrual cycle
  • Psychological & behavioural effects- PMT or PMS, as well as feminising the brain
  • Causing more female type behaviours- sensitivity, co-operation, empathy
• PMT

  Pre-menstrual tension

  -> Breast tenderness, mood swings, and sleep disturbances.
• PMS

  Pre-menstrual syndrome

  -> Bloating, cramping, fatigue, headaches, mood swings, anxiety, depression, memory issues
• What is Oxytocin ?

  A hormone which acts as a neurotransmitter that controls key aspects of the reproductive system
• What is the Role of Oxytocin in gender development?

  • controls aspects of the reproductive system
  • Females release more during birth - helps contractions
  • Promotes intimacy during sex
  • Males- reduction of oxytocin after the release is quicker which explains the sudden loss of intimacy after sex
  • Affects females social behaviour such as male selection and nesting behaviour
• What is the case study of David Reimer about?

  • Born in 1953
  • Botched circumcision at 7 months old
  • Raised as a girl named Brenda
  • Psychological issues led to transitioning back to male
  • Committed suicide in 2004
• Who was John Money and what was his theory?

  He was a psychologist developing the theory of gender neutrality (biological sex is less important than environmental influence in gender identity)
• How was Bruce raised according to Money's instructions?

  He was raised in a stereotypically feminine way- dressed in girls clothes, dolls to play with
• What was the outcome of Brenda's life as a girl?

  She experienced severe psychological and emotional problems
• What happened when Brenda was told the truth about her identity?

  She transitioned back to living as a man named David but committed suicide in 2004
• What does David's transition back to a man suggest about biological influences?

  It suggests that biological influences are more important than socialization
• What chromosomal pattern did David have?

  He had the male XY chromosome pattern
• What hormone levels did David's brain receive during fetal development?

  Normal levels of testosterone
• What was the effect of treating David as a girl for many years?

  It did not affect his identity as a man, otherwise he would’ve stayed a woman
• What is male hypogonadism?

  It is a condition caused by a man's testes failing to produce normal levels of testosterone.
• What was the duration of testosterone therapy in the study by Christina Wang et al.?

  The therapy lasted for 180 days.
• What changes were monitored in the study involving testosterone therapy?

  Changes in body shape, muscle strength, sexual function, and libido were monitored.
• What improvements were observed with testosterone replacement therapy?

  Improvements in sexual function, libido, mood, and significant increases in muscle strength were observed.
• What does the study by Christina Wang et al. suggest about testosterone's influence?

  It suggests that testosterone exerts a powerful and direct influence on male sexual arousal and behavior, as well as physical development in adulthood.
• What type of study did Daryl O'Connor et al. conduct in 2004?

  They conducted a double-blind, placebo study- increased testosterone levels in healthy young men
• What were the findings regarding sexual behavior in the study by Daryl O'Connor et al.?

  There were no significant increases in the interactional (frequency of sexual intercourse) or non-interactional (sex drive) components of sexual behaviour in participants.
• What was observed regarding aggression or anger levels in the study by Daryl O'Connor et al.?

  Men in the study experienced no change in their aggression or anger levels
• What does the study by Daryl O'Connor et al. suggest about additional testosterone?

  It suggests that additional testosterone may have no effect on sexual or aggressive behavior.
• What do Geert Hofstede et al. argue about gender roles?

  They argue that gender roles are more a consequence of social norms than biology.
• How are masculinity and femininity linked according to Hofstede et al.?

  They are linked with whether cultures are individualist or collectivist.
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  What characterizes countries that are more masculine in their outlook?

  They place individual competition and independence above the needs of the community.

  > Capitalist societies (USA, UK)- traditional masculine traits are more highly valued
• What does Hofstede et al.'s research challenge regarding biological explanations of gender behavior?

  It challenges the idea that biology is the sole determinant of gender behavior and suggests social factors may be more important.
• What are the criticisms of the biological approach to gender behavior?

  • It is reductionist.
  • It ignores cultural and societal influences.
  • It overlooks changes in thought processes.
  • It underplays the influence of family and early upbringing.
• What does the biological approach suggest about gender influences?

  • Gender is influenced by chromosomes and hormones.
  • It has been criticized for oversimplifying gender behavior.
  • It does not account for the complexity of gender influences.