Biological Explanation

• Brain sex theory - suggests that dysphoria is caused by specific brain structures that are incompatible with a persons biological sex
• Zhou

  Studied the bed nucleus of the stria terminals (BSTc) which assumed to be fully developed at the age of 5 and around 40% larger in males that females
• In post mortars of six male to female transgender individuals who had received feminising hormones, the BTSc was found to be a similar size to that of heterosexual women
• Kruijiver et al

  Focused on the number of neutrons in the BTSc rather than the volume.

  The six transgender individuals showed a similar number of neurons in BTSc to those found in heterosexual women
• AO3

  This evidence seems to play an important role in explaining GD, although it is not clear these differences were present at birth or a result from many years of more feminine behaviour

  It has also been suggested that BTSc size was likely to have been affected by the hormone therapy
• AO3- Pol

  Studied changes in the brain of transgender individuals undergoing hormone treatment and recorded them using MRI scans. They showed that there was significant changes in the BSTc during that period
• AO3 - other brain differences support the brain sex theory

  Rametti studied another sexually dismorphic aspect of the brain known as white matter (nerve fibres)

  They analysed the brains of both males and females transgender individuals before hormone therapy and found the amount of white matter corresponded more closely to the gender the individuals identified with