3. Role of Chromosomes + Hormones

• 1. Role of Chromosomes + Hormones

  Chromosomes (in nucleus, carry info in genes).

  • 23rd pair determine biological sex.

  Hormones (chemical substance circulated in blood).

  • regulates activity of cells/organs.
• 1a. Role of Chromosomes + Hormones

  Biological perspective, sex/gender same.

  • behavioural/psych/social diff between sexes due to physiology.
  • genes determine male/female + which hormones produced = gender identity.
• 2. Role of Chromosomes + Hormones

  Testosterone - hormone from androgen group; male testes.

  • development male sex organs + secondary sexual characteristics (puberty).
  • high levels = high aggression (explains higher aggression than women).
  • Poll (1998), female rats w/ testosterone = high agg.
• 2a. Role of Chromosomes + Hormones

  Oestrogen - female secondary sexual characteristics (breast development + menstruation/reproductive).

  • high emotions/irritability in menstrual cycle (explains more emotions than men).
  • PMS = disorder.
• 2b. Role of Chromosomes + Hormones

  Oxytocin - released in large quantities during labour/after childbirth.

  • bonding (men + women), mother-baby bonding.
  • calming effect.
  • reduce stress hormone (cortisol) - F/F response.
  • females, ’tend + befriend‘ (protective + alliances).
  • not happen in men, testosterone dampens effect of oxytocin hormone.
  • ‘love hormone’; equal amounts in sexes during kissing/sexual intercourse.
• 3. Role of Chromosomes + Hormones

  Process:

  • Chromosomes (made from DNA) + genes (sections of DNA) determine characteristics.
  • 46 chromosomes in body; 23 pairs — 23rd pair determines biological sex.
  • Eggs produced by ovary = X chromosome; sperm has X (girl) or Y (boy) chromosome.
• 3a. Role of Chromosomes + Hormones

  Process:

  • Y-chromosome carries SRY-gene = testes grow in XY embryo.
  • produce androgens = embryo becomes male as testosterone produces male genitalia.
  • testosterone acts on brain, alters organisation to ‘male pattern’.
  • w/o high androgen levels, embryo develops female.
• 3b. Role of Chromosomes + Hormones

  Process:

  • chromosomes (genetic transmission) explains how individuals acquire sex + which hormone produced.
  • explains aspects of gender bc link between chromosomes (genes), genitalia + hormones.
• 4. Role of Chromosomes + Hormones

  Real-Life Application - David Reimer:

  • Bruce + Brian Reimer born twin boys.
  • botched circumcision, Bruce no penis.
  • parents worked w/ psychologist (John Money), theory gender neutrality.
  • Bruce, now Brenda, raised stereotypically feminine.
  • Brenda never adjusted to life as female, when told truth, went to being a man — David.
  • 2004, suicide.
• Role of Chromosomes + Hormones (Evaluation)

  Strength:

  P - influence of chromosomes on gender identity supported by David Reimer case.

  E - Dabbs (1995), prisoners w/ high testosterone more likely commit violent/sexual crime.

  E - Goozen (1995), transgender undergoing hormone treatment, injected w/ opposite sex; male-to-female, lower aggression.

  L - sex hormones, influence on gender behaviours.
• Role of Chromosomes + Hormones (Evaluation)

  Limitation:

  P - double-blind study, Tricker (1996), males given weekly testosterone or placebo.

  E - no significant difference in aggression across 2 groups; suggests sex hormones little effect on gender-related behaviour.

  E - studies of biological factors in gender = small samples of unusual people/animals.

  L - low generalisability.
• Role of Chromosomes + Hormones (Evaluation)

  Limitation:

  P - question effects oestrogen level on women’s mood + challenge medical category PMS = stereotypes.

  E - Rodin (1992), PMS social construct, way of privileging certain groups over others.

  E - feminists, medicalisation of women’s lives + dismiss emotions by explaining through biology.

  L - androcentrism.
• Role of Chromosomes + Hormones (Evaluation)

  Limitation:

  P - Maccoby + Jacklin (1974), more difference in behaviour within sexes than between.

  E - SLT, importance of social context in learning gender identity/role.

  L - influence of social norms explain cross-cultural diff in gender behaviour + in Western society as male/female become more androgynous.