Gender: chromosomes and hormones

• What chromosome combination leads to female development?

  XX - receive X from mother and X from father
• What chromosome combination leads to male development?

  XY - X from mother, Y from father
• What triggers hormone release at about 8 weeks after conception?

  The gene on the 23rd chromosome
• What hormone is primarily produced in males due to the Y chromosome?

  Testosterone
• What are some secondary sexual characteristics caused by testosterone?

  Facial hair and deepening voice - occur when testosterone is released in higher quantities at puberty in males
• What hormone do ovaries produce in females?

  Oestrogen
• What secondary sexual characteristics does oestrogen cause?

  Breast growth and menstrual cycle
• What is oxytocin often referred to as?

  The love hormone
• What effects does oxytocin have on anxiety?

  Reduces anxiety by lowering cortisol
• How does oxytocin influence social behavior?

  Promotes bonding and sociability
• What alternative response does oxytocin promote in females during stress?

  Tend and befriend response
• What gender difference in stress response does Taylor (2002) highlight?

  Females tend to use tend and befriend - therefore idea of fight or flight is gender bias as it minimises gender difference - beta biased
• What did Van Goozen et al (1995) study focus on?

  Transgender individuals and hormone effects
• What behavioral changes were observed in transgender women in Van Goozens’ study

  Decrease in aggression and visuospatial skills
• What happened to Reimer after his circumcision accident?

  He reverted to being male after being raised as a girl, but was born as a male
• What does Reimer's case suggest about gender development?

  Biology may be stronger than upbringing - nature nurture debate
• What did Gorski et al discover about male and female rat brains?

  Structural differences in the sexually dimorphic nucleus in the hypothalamus - gorski attributed this to exposure to testosterone in the womb
• What is the sexually dimorphic nucleus associated with?

  Prenatal exposure to testosterone
• What did Eisenegger et al (2010) find about expectations and behavior?

  Expectations can influence behavior in bargaining - therefore Van Goozen‘s findings may have been in part due to expectations and the desire to change of the individual studied
• What was the outcome of Tricker's (1996) study on testosterone injections?

  No significant differences in aggression found
• What is Klinefelter's Syndrome characterized by?

  XXY chromosomal pattern
• What are some physical characteristics of Klinefelter's Syndrome?

  Taller than average with weaker muscles
• What psychological characteristics are common in Klinefelter's Syndrome?

  Poor verbal skills and weak memory
• What is Turner's Syndrome characterized by?

  Only one X chromosome
• What are some physical characteristics of Turner's Syndrome?

  Shorter than average with webbed neck
• What psychological characteristics are common in Turner's Syndrome?

  Superior reading ability but poor spatial skills
• What are the strengths and weaknesses of research into atypical sex chromosome patterns?

  Strengths:

  • Contributes to nature/nurture debate
  • Helps identify psychological differences

  
  

  Weaknesses:

  • Correlation does not imply causation
  • Environmental influences may affect behavior
• What practical applications arise from research into Klinefelter's and Turner's Syndromes?

  • Earlier and more accurate diagnoses
  • Better outcomes for individuals diagnosed young
• What individual differences should researchers consider in Klinefelter's and Turner's Syndromes?

  • Mosaic forms of the syndromes exist
  • Symptoms can vary significantly among individuals
• What are male sex hormones called

  Androgens
• what does the presence of the Y chromsome cause the production of

  androgens
• what do androgens (mainly testosterone) lead to whilst the baby is still in the womb

  The production of the testes and penis
• what does the lack of testosterone lead to the development of a baby girl in the womb

  ovaries and vagina
• Where is oxytocin produced

  The pituitary gland
• what does oxytocin promote in males and females

  Bonding
• what effect does testosterone have on oxytocin

  testosterone diminishes the effect of oxytocin
• what is the effect of oestrogen on oxytocin

  oestrogen increases the effect of oxytocin
• did Gorski find a difference in the SDN in male and female rats

  SDN was larger in male rats than female rats
• Which sex does Klinefelters syndrome effect

  Males
• which sex does Turner’s syndrome effect

  females