As I indicated in my original post on this subject, the question of just how many gender variant people there actually are out there is quite a contentious one. With this in mind, I thought it would be a good idea to have a single resource referencing all the different positions, which people could then read for themselves and make up their own minds on, hence this page. It’s based on the above-mentioned post, and as I come across more resources around this question I’ll blog about it and add it here.
I’ve decided to list publications and events as they’ve occurred, with more investigations listed chronologically down the page. Thus the latest items may be found at the bottom of the page, with the older ones listed at the top. Hopefully this will provide an understanding, not only of the findings themselves, but also place them into context and give an idea of why such controversy exists around the issue. For convenience, I’ve also included a short summary of findings for each resource listed.
If you happen across resources that I’ve not listed, please do tell. You can either post about it as a comment or send me an email and I’ll include it ASAP.
Notes on Populations
- Overall population statistics are assumed to be a 50% split between assigned male and assigned female.
- Adult population aged 18-60 is estimated at two thirds of total population, 67%.
- You’ll notice that most of these studies focus exclusively on Male-to-Female (MtF) transsexual people, specifically post-op. This is done mainly because it’s easy – you can point to a definite, irreversible change and obtain statistical data from surgeons fairly easily. Obviously this precludes gender-variant people who can’t have surgery due to financial or health restrictions, or who do not entirely identify as transsexual.
- Reliable statistics for the Female-to-Male (FtM) population are much harder to come by as phalloplasty is a much more expensive, dangerous and generally unsuccessful procedure than vaginoplasty. Consequently, many transmen opt not to have surgery, and so never become part of a fairly easily counted population. Historically the ratio has been about one FtM individual for every 2.5 MtF people. Where there’s no data I’ve used this ratio to extrapolate numbers for comparison.
- These statistics tend to assume that the majority of the population will have access to information about transsexuality as well as the means to medically transition, since they are based on research in developed countries such as the Netherlands and the United States. The reality in less developed countries is unlikely to correspond to these models. Populations are more likely to be ignorant of the realities or even existence of gender variance, not to mention have little chances of ever having the resources to transition.
In 1988 Professor W.F. Tsoi, Head of the Department of Medicine at the National University of Singapore published a report containing an estimation of the number of transsexual people in Singapore, determined by counting the number of people in Singapore seeking sex-reassignment surgery and consequently diagnosed as being transsexual. The study found a ratio of one in 2,900 for male-assigned transsexual people and one in 8,300 for female assigned individuals.
[Bakker, Kesteren et al] The Prevalence of Transsexualism in the Netherlands (1993, archived at Lynn Conway’s Website)
In 1993, A. Bakker and his team published a study on the prevalence of transsexualism in the Netherlands, reporting ratios of one in 11,900 males and one in 30,400 females. Treatment and research of transsexual people in the Netherlands is quite advanced compared to the rest of the world, and these statistics were gathered by the endocrinology department at the Free University Hospital in Amsterdam.
These numbers were reported with a very important caveat attached to them though, one which seems to subsequently have been ignored or forgotten by many:
The prevalence of transsexualism in the Netherlands was estimated by counting all the subjects who were diagnosed as transsexuals by psychiatrists or psychologists and were subsequently hormonally treated and generally underwent sex-reassignment surgery.
As clearly stated, only those gender variant people who actually went on to transition formed part of the final report. Androgyne or Neutrois individuals, along with those who could not have surgery for whatever reason were simply not counted at all.
[Wilson et al] The Prevalence of Gender Dysphoria in Scotland, A Primary Care Study (1999, IngentaConnect)
Based on a questionnaire sent out to senior partners at general practices in Scotland, it was found that 8.18 in every 100,000 patients suffered from gender dysphoria. This equated to a MtF ratio of one in 7,641, and a FtM ratio of about one in 30,562. However, the report goes on to state the following:
One-third of gender-dysphoric patients known to practices had registered in the preceding 12 months, suggesting that patients with this condition are increasingly likely to present for medical care.
Clearly showing that the final results couldn’t be regarded as an overall population. Either the number of transsexual individuals in Scotland were increasing exponentially, which is unlikely, or more likely many gender variant people are simply not seeking treatment, whether out of fear or ignorance, indicating that the gender variance is vastly underreported.
The World Professional Association for Transgender Health (WPATH), formerly The Harry Benjamin International Gender Dysphoria Association (HBIGDA) lists official numbers of one in 11,900 males and one in 30,400 females, based on findings on [Bakker93]. It does however point out that these numbers may be considerably higher. From page two:
The earliest estimates of prevalence for transsexualism in adults were 1 in 37,000 males and 1 in 107,000 females. The most recent prevalence information from the Netherlands for the transsexual end of the gender identity disorder spectrum is one in 11,900 males and one in 30,400 females. Four observations, not yet firmly supported by systematic study, increase the likelihood of an even higher prevalence.
In January of 2001 Lynn Conway published a report detailing her research into the true numbers of transsexual women in the United States. Her approach was simply to count the number of post-op US MtF citizens and divide that number by the total number of adult assigned males for a ratio. Her results were startling, to say the least: one in ever 2,500 assigned males between 18 and 60 have had SRS, for a total population of between 32-and-40,000 people. Considering the financial and procedural obstacles gender-variant people face in obtaining treatment, she estimated the number of untreated individuals to be between three and five times that number, for a lower margin of one in 500 assigned males.
Extrapolating these same findings for FtM people, you’d be left with a ratio of about one in 1,250 assigned females. I’ve not calculated a ratio for post-ops as it would be a fairly meaningless statistic for the reasons listed under Notes on Populations above.
Donna Kelley duplicated Professor Conway’s method in the same year of 2001 and counted the number of male-assigned UK citizens who had completed SRS either in the UK or abroad. She ended up with a ratio of 1 in 3,750 individuals. She surmised that the lower incidence was probably due in large part to the relative ease with which US citizens could access competent SRS surgeons, many of whom are resident either in the US or Canada. By contrast, transsexual people from the UK and other parts of the world typically have to fly either to North America or to Thailand for surgery.
In 2002, Sam Winter, an academic at Hong Kong university did an informal study on the number of transgender people, “kathoey” in the Thai language. Using kathoey assistants as “spotters”, Mr. Winter simply counted the number of passers-by in various locations, and had his assistants count the number of kathoey who happened by. They found a remarkable number of 3 in every 1,000 people, a ratio of one in every 167 assigned males.
Incidentally, Mr. Winter cites an estimate made by Richard Ehrlich in 1996 of 10,000 kathoey in Thailand. These include post-op, pre-op and non-op, and is a total population for male-assigned gender variant people. With a population of roughly 58.9 million in 1666, that equates to 1 in 1,963 assigned males. Mr. Winter regards this a conservative opinion, citing some estimates of up to 300,000.
[Conway and Olyslager] On the Calculation of the Prevalence of Transsexualism (2007, archived at Lynn Conway’s Website)
After having little success in convincing the medical and psychiatric establishment of her findings, Professor Conway followed up on her 2001 report with a presentation in 2007 at WPATH’s annual symposium. Co-authored with Femke Olyslager, the report presented a thorough re-evaluation of past studies, including those by Bakker in 1993 and Tsoi in 88, along with Professor Conway’s own findings and that of other individuals within the gender-variant community. From page one, Abstract:
From this reanalysis of those early reports, we determine lower-bounds on the prevalence of the underlying condition of transsexualism to be between 1:1000 and 1:2000, using those reports own data. We then present more recent incidence data and alternative methods for estimating the prevalence of transsexualism, all of which indicate that the lower bound on the prevalence of transsexualism is at least 1:500, and possibly higher.
[Reed et al] Gender Dysphoria, Transsexualism and Transgenderism: Incidence, Prevalence and Growth in the UK (sep 2008, Gender Identity Research and Education Society (Gires))
In a presentation at the LGBT Health Summit in Bristol (UK) in 2008, Gires estimed an prevalence of 21 individuals per 100,000, with a ratio of 4 MtF for ever FtM, based on [Wilson99]. This leads to ratios of one in 2,976 for MtF transwomen and one in 11,905 for FtM transmen, consistant with Lynn Conway’s findings in 2001.
However, the report goes on to state that prevalence might be as high as 600 individuals per 100,000. Applying the same ratio of ratio of 4 MtF for ever FtM individuals, that equates to estimates of one in 104 assigned males and one in 416 assigned females.
The report also finds that the population may be growing by as much as 12% per annum
The full presentation may be viewed here.
The Diagnostic and Statistical Manual of Mental Disorders, currently undergoing its fifth revision (slated for publication in 2012), is considered the “Bible of Psychiatry”. It is used by doctors and mental health professionals in their diagnosis and treatment of gender variant people, and by insurance companies and publically funded healthcare in determining whether gender variant people should be covered or not. The inclusion of Gender Identity Disorder in the DSM, starting with revision 3, has also been responsible in large part for securing what legal rights gender variant people enjoy.
Owing to the potential impact this document might have on the lives of gender-variant people, Professor Conway and other activists are currently contesting the matter of prevalence very strongly with the APA Task Force responsible for the DSM’s revision. Sadly this fight has turned nasty at times, as detailed at the main link.