Boys already have testosterone, so giving a boy more testosterone than they already have isn't going to alleviate the dysphoria;
I have heard this line of reasoning before, and I believe the idea behind it was that insufficient natural hormone production could be causing dysphoria, and by increasing that production you could fix the dysphoria to a degree. I have not read any studies either way on this.
Transgender and gender diverse (TGD) people have a gender identity that differs from societal expectations based on their sex assigned at birth. In the United States, ∼1.8% of adolescents and 0.6% of adults identify as transgender.1,2
so what are the causes of 3 fold decreased incidence?
Children's identities are, in general, in a higher degree of flux than adults'. Things just change as you age out and discover yourself and work through your youthful confusion.
The question for the survey cited is vague on how someone who is genderqueer/fluid should respond also (this is typical). I think it's far more accurate to consider only those who actively pursue HRT/surgery. Given what I suspect to be a wide spectrum of genderqueerness/transgenderness, that's sort of a "show don't tell" approach to demographics, and more reliable than self-reporting surveys, which are not the best form of scientific inquiry.
You're also asking children whose understanding of terms and medical/social issues is generally limited. Ask how many children are going to be doctors when they grow up, and compare that to the actual number of practitioners, the difference will be severe as well. Most don't realize the high levels of effort and commitment needed to become doctors, and ultimately accept being nurses or accountants instead... And they're happy enough as that, even if in a perfect world they'd be a doctor.
You also have the combined issues of repression in prior generations mixed with promotion in the younger generation. Time will tell how that balances out.
Here:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5841333/
The number of people who seek treatment suggest that male-to-female transsexualism has a prevalence of 6.8/100,000 and female-to-male transsexualism has a prevalence of
2.6/100,000 among adults.
4,
5 In the Netherlands, 0.6% of men and 0.2% of women (aged 15–70 years) reported incongruent gender identity and a desire to undergo sex reassignment (SR).
6 Population surveys have suggested that about 0.5% of adults in the general population identify as transgender.
5,
7
The number of adolescents contacting specialized gender identity services has risen considerably over the past decade across Europe and North America.
8,
9 No conclusions regarding the prevalence of GD in general or of GD/transsexualism specifically can be drawn based on these increases. Studies using short (one to three item) self-reports of gender identity and its variance suggest that 0.17%–1.3% of adolescents and young adults identify as transgender.
5,
10 A school-based survey eliciting gender experiences with scales commonly used at gender identity services suggested that 1.3% of 16–19 year olds had potentially clinically significant gender dysphoria.
****
https://en.wikipedia.org/wiki/Transgender
estimated that 89,667 individuals included in the 2010 Census had changed to an opposite-gendered name, 21,833 of whom had also changed sex marker.
[181] Prevalence in the States varied, from
1.4 to 10.6 per 100,000.
****
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4823815/
Overall mP [meta-Prevalence] (95% CI)
per 100,000 population was 9.2 (4.9, 13.6) for surgical or hormonal gender affirmation therapy and
6.8 (4.6–9.1) for transgender-related diagnoses. Among studies assessing self-reported transgender identity, the mP was 871 (95% 519, 1224); however this result was influenced by a single outlier study. After removal of that study, the mP changed to 355 (95% CI 144, 566). Significant heterogeneity was observed in most analyses.
You have something around 0.7% of children "identifying as transgender" (maybe as high as 1-2%), with only 0.0068% actually committing to medically it in the first study.
In the census, it's 0.01% as of 2010.
In the meta-study, it was about the same as the first.
With how promoted it is and accepted it is at least among other children these days, you would expect more than a 1000:1 ratio there if all ~0.7% or so were fully transgender. This leads me to believe the prevalence of true and non-fluid gender dysphoria is drastically lower than the 0.5-1.5% self-reported number pushed by advocates, even if it's ultimately higher than the 0.01% number.
That's what I've been trying to get at with my prior blog posts here: if you start expanding the scope beyond that 0.01% demographic, at what point does the harm from transitioning clueless children who end up being gendernormative more or less in adulthood outweigh the benefits of appropriate transitions?
We simply do not have clear data even on how many people are in either group yet, nevermind a full understanding of the psychology and neuroscience underlying it.
This is the definition of experimental and unclear medicine.
How loose do we want to play it going forward?