influence of chromosomes and hormones

• What are CHROMOSOMES?

  • Made from DNA
  • 23 pairs
• What are GENES?

  Short sections of DNa that determine the characteristics of living things
• Chromosomes

  •  Y chromosome carry gene: sex-determining region Y = SRY
  • SRY gene causes tests to develop in XY embryo; ANdrogens are produced – the male sex hormones
  • androgens causes embryo to become male
  • If no androgens produced, embryo develops as a female
• Hormones

  Chromosomes determine sex, hormones influence gender development    

  1. Prenatally:

  • hormones act upon brain development
  • Development of reproductive organs + genitalia

  1. Puberty

  • Development of secondary puberty characteristics
  • E.g pubic hair, breasts
• David Reimer

  Research support for the influence of biology on gender development
• David Reimer's life

  1. Accidentally castrated at birth

  2. Made to live life 'as a girl'

  3. Took feminising hormonal drugs that had physical effects (feminised his face)
• Despite taking hormonal drugs

  David still internally felt 'wrong' and fluttered more towards a 'tomboy' showing that he resonates with his biological sex
• David Reimer's experience

  • Had social effects, he was bullied and had serious suicidal thoughts/depression
  • Upon finding out he was initially a boy, he transitioned into David showing his biological sex was more comfortable
• David Reimer's case shows that there are high biological influences rather than social as despite being raised as a girl, David felt most comfortable with his initial biological sex
• David Reimer's case has external and ecological validity as it is a real life application
• Reductionist view on gender development

  There are other factors on gender development such as 

  • cognitive influences
  • Role of schema

  Schema is our blueprint for things, people’s schema for gender differs and develops and will shape how we decided to express gender Schema for masculinity and femininity differs between cultures, and individuals

  • Underplays alternative explanations
  • Not satisfactory on its own
• Ignores influence of social factors
• How we interact with society/how we are raised shapes what we believe is acceptable/supposed to act for certain genders, and shapes how we develop our gender expressions
• Individual cultures are more likely to prioritise their independence rather than community and this would be seen as masculine traits
• Collectivist cultures are more likely to focus on community rather than the individual and this is associated with femininity (nurturing)
• Downplays the role of other factors that do have large influences
• Means biological explanations can not be used alone
• A much better/logical explanation is that both biological and social explanations are true
• Research/Evidence support for how hormones influence gender development

  Wang et al (2000)

  • 227 hypognadal men given testosterone fo 180 days
  • Changes in body shape, muscle strength, sexual function & libido measured
  • After the 180 days, significant increase/strengthened for all