The Male vs Female brain is a great topic of conversation, because if Transgender brains are indeed so similar to their opposite sex counterpart that it is the biological or congenital cause of their desire to change their identity, we would expect to see the use of MRI imaging in detection and diagnosis.
Instead, in the United States, United Kingdom, Canada and Australia, the diagnostic manuals rely on a self-reporting and persistence model, and do not use MRIs or any kind of brain scan at all to confirm this self-diagnosis. Why is that, when everyone is saying transgender individuals are “born in the wrong body”?
Existing studies “are yet to provide consistent results on exploring the difference of brain structure between men and women” (Ingalhalikar et al. 2014).
So just how different are our brains, and how significant is that difference?
Firstly, you would see more of a difference between any two brains than between male and female brains overall.
Secondly, neuroplasticity, the brain’s ability to “reorganise itself” means that over time our brains change in response to environment, activities we engage in, illness, injury and disease. So the commonly used catch phrase that our brains are “hard wired” is not a good description of our brains.
Studies that aim to show the difference between the sexes report conflicting results and vary depending on the age or stage of life of the subjects. This is due to the interplay of several factors including genetics and environment. Merely knowing there are on average differences does not automatically translate to explaining reasons for differences in behaviour between the sexes.
Professor of neurobiology at the University of Chicago, David Freedman, says: because the experience of being a male is fundamentally different to the experience of being a female, it throws a spanner in the works when you try to make correlations between brain difference and behaviour.
It is highly likely that differences in life experiences equate to differences in the brain ie. brain plasticity.
A study of London taxi drivers, found that the hippocampus – a structure responsible for long-term memory and spatial navigation – grew after the drivers gained experience navigating the city streets. You could scan the brains of cab drivers and see that they had larger hippocampi than the average person, but only scanning their brains over time would tell you whether their occupation led to that size difference or the size difference led to their choice of occupation.
For example, a UK study published in May 2018 of 5,216 mostly middle-aged subjects, the largest study ever of the structural and functional sex differences in the human brains of men and women showed “considerable distributional overlap between the sexes“. This was not a gender identity study on whether a person had many frocks in their wardrobe or preferred ball sports. Testing was on structural and functional brain differences using cognitive testing as well as MRIs.
With such a high degree of overlap, shouldn’t we would expect to see, say, 40% of people being transgender or unsure of their gender identity? Instead, it’s only 0.6%.
~ Alegria, Guest Author
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Sex Differences in the Adult Human Brain: Evidence from 5216 UK Biobank Participants
Oxford University Press
Sex differences in the human brain are of interest for many reasons: for example, there are sex differences in the observed prevalence of psychiatric disorders and in some psychological traits that brain differences might help to explain.
Brain Differences Between Men and Women: Evidence From Deep Learning
National Center for Biotechnology Information, U.S. National Library of Medicine
Do men and women have different brains?
Is There a Difference Between Male and Female Brains?
Last month, UK researchers published the largest study ever of structural differences in the brains of men and women, looking at a whopping 5,216 brains in all.
Medical Definition of Neuroplasticity
Neuroplasticity: The brain’s ability to reorganize itself by forming new neural connections throughout life.