
Research: testosterone changes brain structures in female-to-male transsexuals [pdf] - no1ne
https://www.ecnp.eu/~/media/Files/ecnp/About%20ECNP/Press/AMS2015/Hahn%20PR%20FINAL.pdf
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Avshalom
I mean sure, yeah, but...

[https://hn.algolia.com/?query=changes%20brain&sort=byPopular...](https://hn.algolia.com/?query=changes%20brain&sort=byPopularity&prefix&page=0&dateRange=all&type=story)

so does meditation, walking in nature, inactivity, porn, drugs, focus,
menstruation, Alzheimer's, cellphones, the iInternet, The Knowledge,
programming, football...

changing it's structure is how the brain reacts to basically any regular
stimulus. Thats how it works.

~~~
irremediable
Agreed. Also, I've not read the paper yet, but I'll be very interested to see
the effect size. Lots of sex differences neuroimaging papers rave about
significance while ignoring the minuscule scale of effects.

~~~
WalterSear
Significance == publication, prestige, advancement

Effect power == bury it in the results, give it a one line 'yeah, we noticed
that' in the discussion, so the publication reveiwer can't accuse you of
missing something.

~~~
irremediable
Indeed. It's all too tempting -- I've often found myself overlooking it a bit
in my own work. When appropriate, I try to summarise key numbers, significance
tests and effect sizes all in one table to avoid that problem.

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vlehto
I have MtF friend. We knew each other when we still we're both officially men.
We became roommates for a year when she was mid transition.

I thought that would be cool, because I might understand women better now that
I had somebody who had seen the both perspectives. How it is to be a man and
how it is to be a woman.

I was wrong. She had never understood anything about manhood. Now she didn't
even pretend anymore. I think there are some real and big differences between
the sexes, but I still don't have good grasp about them.

~~~
davess1
Could you elaborate more? What are some of the differences she didn't
understand?

~~~
abathur
I think the point vlehto is trying to make is:

He expected his friend, who he perceived as a "man", to have a particular kind
of insight after the transition. Instead, he learned that his perception of
the friend as a "man" was a projection. His friend would not have felt the
need to transition if she felt she was a "man."

His friend could only provide more nuanced insights, because her experience
was not that of a "man" becoming a "woman."

~~~
coldtea
I think this explanation has the opposite effect: it cheapened the nuances of
what he said.

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csours
I had a (male) colleague once argue with me that men and women had no
differences in mentality due to testosterone. The desire to believe in
equality is weird sometimes.

To be clear, I don't think there is any difference in generic mental abilities
due to gender / sex, but it seems clear that brains would be affected by
hormonal differences - for instance I have a thyroid deficiency, and I can
really feel it when I'm low.

~~~
BurningFrog
There are definitely differences in both generic mental abilities and what
fields interest people between the sexes. From an evolutionary biology
perspective, it would be really weird if there weren't.

To be clear, men and women are equally mentally gifted as a whole, but focused
on different skills, and with bigger variance in men.

Pinker's "Blank Slate" lays out the case well: [http://www.amazon.com/The-
Blank-Slate-Modern-Denial/dp/15012...](http://www.amazon.com/The-Blank-Slate-
Modern-Denial/dp/1501264338)

~~~
esailija
You mean evolutionary _psychology_ , not biology. The former is basically a
pseudoscience and the latter makes no such claims.

~~~
BurningFrog
I'm not even saying this is an established scientific claim, only that it
would be _really_ weird if the statistical differences between men and women
were 100% outside of the brain, given how different the evolutionary pressures
are.

Evolutionary psychology does have some problems :) It's easy to tell dazzling
and believable stories in that frame, but much harder to prove them
empirically.

I think some real science is being done in the field, but I agree that when
people make EP arguments on the internet, you need to apply a lot of
skepticism.

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peterwwillis
It's unfortunate that changes in the brain is all they studied. If you have 18
people who are undergoing this transition, it would be useful to document any
other changes and note them as candidates for further study.

For example, many people will remark on an increased sex drive (not a surprise
considering the testosterone), but the way people actually think about and
treat the opposite gender seems to change as well. It would suggest that
testosterone has a part to play in the development of gendered social
structures. But who knows?

~~~
transman
> It's unfortunate that changes in the brain is all they studied. If you have
> 18 people who are undergoing this transition, it would be useful to document
> any other changes and note them as candidates for further study.

As a transman with a background in the sciences (social), I was actually
really disappointed that there weren't any attempts to systematically gather
this data when I was transitioning. I agree, it could bring a lot of data to
the table that otherwise can't be ethically collected. Of course, in reporting
any correlations there would need to be clear indications that the data came
from the transexual community.

> many people will remark on an increased sex drive (not a surprise
> considering the testosterone)

Holy smokes! I was prepared for an increase, but I was totally not prepared
for the amount of increase! I transitioned several years ago, and this change
was definitely the one I was least prepared for.

> but the way people actually think about and treat the opposite gender seems
> to change as well.

Caveats galore: I don't think _I_ treat the "opposite gender" any differently
(to be clear, I was born in a female body, but identify as a guy, so "opposite
gender" for me has always been women). But, I am very definitely treated
differently _BY_ many people, including women, now that I pass, i.e. I am seen
as guy. As a result, I definitely treat _individuals_ of the opposite gender
differently _because of how they treat me_. For example, I can't stand women
who complain about being discriminated against, but then _clearly and
unambiguously_ discriminate against me _because I appear to be a privileged
white guy_. I simply couldn't judge this when I passed as a woman (I was aware
that it happened, but without being a participant it's hard to determine
whether that is in fact what's happening.) I now pass enough that I've
experienced this with quite a few women. I've also dealt with more than a few
women who are so hell bent on how they've been wronged, that they won't work
with me _because I 'm a guy_. The irony is that because I pass, when I'm in
predominantly or exclusively male groups, I'm better able to argue for things
which will reduce actual discrimination and bias against women.

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oldmanjay
You should see what it does to structure in utero!

------
stefantalpalaru
Beautiful example of politics driving research. They only studied something
they knew was a disadvantage for males, while the first thing everybody is
curious about is how the IQ changed, if it changed:
[http://www.independent.co.uk/news/education/higher/dr-
paul-i...](http://www.independent.co.uk/news/education/higher/dr-paul-irwing-
there-are-twice-as-many-men-as-women-with-an-iq-of-120-plus-426321.html)

~~~
BurningFrog
It's a little weird to say males have higher IQ on average.

As I understand it (I'm not an IQ expert, just some internet know-it-all),
women score better on some categories of questions, as do men, so when you put
together a test, you try to make sure it balances out so both get the same
average.

~~~
pygy_
AFAIK the average is the same, but males have a higher variance, meaning that
they are more likely to be found at the dumber and smarter ends of the
population, while there are more women of average intelligence.

~~~
stefantalpalaru
[http://emilkirkegaard.dk/en/wp-content/uploads/Males-have-
gr...](http://emilkirkegaard.dk/en/wp-content/uploads/Males-have-greater-g-
Sex-differences-in-general-mental-ability-from-100000-17-to-18-year-olds-on-
the-Scholastic-Assessment-Test.pdf)

~~~
pygy_
Wow, this is new to me... Please note, however, that this is an indirect
measurement.

