BIO

• What are the strengths of the biological explanations for atypical gender development?

  1. Other structural differences
• What are the limitations of the biological explanations for atypical gender development

  1. Contradictory evidence
  2. Inconclusive nature of twin studies
  3. Socially sensitive research
• Strength BE = other structural differences

  • Evidence suggests other brain differences associated with gender dysphoria
  • White matter is a sexually dimorphic aspect of the brain
  • Regional differences in proportion of white matter in males and females
  • Rametti et al. (2011) analysed brains of male and female transgender individuals (before they began hormone treatment)
  • Mostly, the amount and distribution of white matter corresponded more closely to the gender the individuals identified themselves as rather than the biological sex
  • Scientific credibility
• Limitation BE = contradictory evidence

  • Central claims of brain-sex theory have been challenged
  • Hulshoff Pol et al. (2006) studied changes in transgender individuals‘ brains using MRI scans taken during hormone treatment
  • Scans showed size of BSTc changed significantly
  • Kruijver et al. and Zhou et al. examined BSTc post-mortem and after receiving hormone treatment
  • Suggests that differences in the BSTc may have been effect of hormone therapy rather than gender dysphoria
  • Might explain similarity to gender identity rather than biological sex
• Limitation BE = inconclusive nature of twin studies

  • Twin studies don’t yield very high concordance rates (39% for monozygotic twins in Heylens et al. study)
  • Compounded by fact that findings from twin studies are not always conclusive because they cannot separate effects of nature and nurture
  • E.g. despite dizygotic twins and ordinary siblings sharing 50% of genes, the former often have higher concordance rates
  • May be due to DZ twins being more likely to be raised in a similar environment and so exposed to same social-psychological factors
  • Twin studies only support diathesis-stress model
• Limitation BE = socially sensitive research

  • Research on gender dysphoria has potential social consequences for individuals represented by the research
  • For some individuals, knowing there is a biological basis to their gender dysphoria may be a relief
  • Narrowing the cause of gender dysphoria to that of biology may also help others to be more accepting of trans needs
  • On the other hand, may be harmful as wrongly assumed being transgender is biologically innate
  • Others may object to the label of mental disorder being applied to gender dysphoria as though they are ‘sick’