Gender: Physiology and Hormones

[Missy]

So I've been browsing wikipedia the last couple of days, mostly on the subject of hormones and how they affect human physiology and gender. I was actually kind of curious if anyone knew of a more reliable source of information than wiki to do some more serious research. I've had many curiosities before, but never really ventured too far with any of them so I really have no idea where I should look, any help would be appreciated!

[Pumpkin Seeds]

Not sure what research databases you have access to but CINAHL is good for most medical research.  Your local library may have access to the database if not a local medical school or nursing school.  Asking the librarian there for access should be easy enough if you tell them you are doing some research.  Also their library will have medical journals and research on hormones.  Emailing professors is also a good way to turn up some research leads if not gain an audience to ask question, probably by email.  This, of course, depends on their time schedule.

[AndyZ]

The question of "nature vs. nurture" has been around since antiquity.  "Nature" implies that it's born and ingrained, while "Nurture" implies that the way we are treated develops responses and our personality forms as a result.

Personally, I've always been of the opinion that it's nurture, looking at the Baby X Experiment and how constant the gender roles have been worked as a result.

http://bakingwithexmix.wordpress.com/2011/03/20/x-mix-describes-the-baby-x-experiment/

However, upon typing "nature nurture gender" into Google, one of the first results strongly seems to contradict this idea.

http://www.hopkinsmedicine.org/press/2000/MAY/000512.HTM

If I were to guess, you're researching it in order to better portray a character of the opposite gender?  That's why I personally have.  If you're purely interested with hormones and physiological differences, though, I apologize for wasting your time.

[Missy]

Not sure what research databases you have access to but CINAHL is good for most medical research.  Your local library may have access to the database if not a local medical school or nursing school.  Asking the librarian there for access should be easy enough if you tell them you are doing some research.  Also their library will have medical journals and research on hormones.  Emailing professors is also a good way to turn up some research leads if not gain an audience to ask question, probably by email.  This, of course, depends on their time schedule.

That's perfect! Thanks! I've always had an inner nerd that never got the chance to reveal himself.

I do have access to some college resources, but it's difficult to figure out how to use it properly.

The question of "nature vs. nurture" has been around since antiquity.  "Nature" implies that it's born and ingrained, while "Nurture" implies that the way we are treated develops responses and our personality forms as a result.

Personally, I've always been of the opinion that it's nurture, looking at the Baby X Experiment and how constant the gender roles have been worked as a result.

http://bakingwithexmix.wordpress.com/2011/03/20/x-mix-describes-the-baby-x-experiment/

However, upon typing "nature nurture gender" into Google, one of the first results strongly seems to contradict this idea.

http://www.hopkinsmedicine.org/press/2000/MAY/000512.HTM

If I were to guess, you're researching it in order to better portray a character of the opposite gender?  That's why I personally have.  If you're purely interested with hormones and physiological differences, though, I apologize for wasting your time.

It's funny when you said "Nature vs. Nature" it reminded me of some stuff written by Richard A. Lippa I read last year for a class which has convinced me gender has little to do with personality. At least on an definite level, there are trends, but those are that: general trends. I actually found it rather interesting because, if I am assessing it right, I am, on a psychological level, roughly 50% female. At this point I'm pretty much of the opinion that as Lippa put it "the phrase 'opposite gender' is misleading" (approximated quote) At this point I think most gender differences are physiological and that psychologically we're a lot more alike than we often believe. Of course I'm no expert.

Actually my curiosity on this started with the suggestion that dudes can have boobs. According to wikipedia it's true, we have all the same plumbing but none of the proper hormones. Wiki notes examples of males lactating in certain circumstances however I confess to a wee bit of skepticism without looking into it further.

Anyways reading over the various hormones necessary to Sapien lactation I got around to wondering about testosterone which I also found interesting. At this point I'm just curious about how hormones affect physiology.

I confess to curiosity about my own personal hormonal makeup as well, I'm not as hairy as some guys. I'm not really curious about the Nurture vs. Nature question at this point, but of genetics vs. hormones in physiology. For example different women wear different bra sizes and different guys have various levels of body hair. I'm just curious of the correlation between genetics and hormones, do genetics determine strictly the dosage the individual subject receives or is the dosage irrelevant to genetics and instead has a stronger effect on the 'effectiveness' of hormones. So is it a purely genetic quality that the offspring of busty women will also be busty or do genetics actually effect how much estrogen she actually needs for her breasts to grow a certain degree? As one possible example of the sort of query I'd like to pose. There are plenty of others I'm certain I will pass along sooner or later.

Actually when I play female characters (which I actually kind of prefer) I generally either go with a very fantastical character or just try to play a 'human' character. One who just seems to behave naturally, since I'm of the opinion that any 'oddities' can be explained away by subject personality, or rather: I think gender persona is more general than anything.

Thanks for the links I will give them a look.

[AndyZ]

Well, the first one won't do much for pure physiology.  The second seems very interesting, but in proper scientific method, gives the results but doesn't give much of a how or why.

I know a transgender M>F and she's been growing breasts thanks to medication.  I asked, and apparently simply getting more of that medication wouldn't cause the breasts to grow further.  (If it did, augmentation surgery would quickly become obsolete, which was my reason for asking.)

My personal method that I started with for learning to play females was purely nurture.  I imagined what life would be like if the various aspects were different (bullying being much more verbal and less physical, and a number of more stereotypical expectations which our culture is slowly growing out of, for example) how my perspectives would change as a result.  Of course, it's a drop in the bucket when compared to everything else which shapes a personality.

However, back to topic before I go to bed.

http://en.wikipedia.org/wiki/Sexual_arousal#Hormones_and_sexual_arousal

Several hormones affect sexual arousal, including testosterone, cortisol, and estradiol, however, the specific roles of these hormones are not clear.[49]

I would look into testosterone, cortisol and estradiol.  Also estrogen.

http://women.webmd.com/normal-testosterone-and-estrogen-levels-in-women

Estrogen is an entire class of related hormones. They include estriol, estradiol, and estrone.

Okay, so maybe looking into estrogen also would be redundant...

It's worth noting that both men and women have both testosterone and estrogen.

http://health.msn.com/mens-health/estrogen-not-just-for-females

I'll just pull up random sites as I find them and think they might be useful.

(The condition of enlarged breasts in males is known as gynecomastia.)

Gynecomastia would almost certainly be worth looking into.

http://en.wikipedia.org/wiki/Gynecomastia

Due to excess testosterone levels from steroids, which is converted to estrogen, bodybuilders and other athletes are sometimes afflicted with gynecomastia in its purest form.

Here's a question which certainly feels relevant: why does testosterone convert into estrogen with steroids?  I have a hunch that if you find that out, it might explain quite a bit.


Okay, somewhat random but I hope some of that helps and puts you in a general right track.  If I'm not helping, I won't be offended if you say so ^_^

[Pumpkin Seeds]

With the proper injection of hormones, especially estrogen, men can lactate.  There was a case of a man actually injecting himself with estrogen to the point he was able to breast feed his child. 

[DarklingAlice]

The thing about genetics in sex determination, is that there is almost no role for it. Almost. Sex determining region Y (SRY) is a teensy part of the Y chromosome (which is already a teensy chromosome). It is expressed for only a brief period during embryonic development. SRY is a transcription factor which increases the expression of other proteins, which increase the expression of other proteins, etc. So basically whether you become a male or a female is wholly dependent on whether this first domino in a long chain is knocked over. But after that one initial event there is basically no difference in the actual genes of men and women (you can even have a wholly female XY individual if SRY is silenced during that embryonic period, or a XX male if an error in homologous recombination lets it cross over to the X chromosome). Transexuals on hormone replacement therapy will tend to have similar features to the parent of the sex they are transitioning to (e.g. a MtF can make a guess at her breast development by looking at her mother) because the hormones are interfering with these pathways set up during the early stages of development and essentially giving you the traits similar to those you would have had if you were born the opposite sex.

That said, there is a lot that environmental factors can do to change the expression of hormone production and reception. One of the more prominent examples of this is the direct link between %body fat and estrogen expression (which, since estrogen is a required co-factor for shuttling across the blood brain barrier, then changes how you respond to other hormones, like Leptin). So to put this specifically in terms of breast growth it is likely a combination of genetic and lifestyle factors (since children often live a similar lifestyle to their parents).

And as for references, always check the NCBI first. They have tons of lovely databases and are pretty good at guiding you to free content even if you don't have access to a library or school.

[Somnifera]

With the proper injection of hormones, especially estrogen, men can lactate.  There was a case of a man actually injecting himself with estrogen to the point he was able to breast feed his child.

Estrogen is not responsible for lactation. However, prolactin is. Hormones have a synergistic relation to one another, and therefore it is not the presence of one vs. the other that dictates the reaction, but the ratios therein.

Lactation can also be stimulated in women by ingestion of lactogogues such a s fenugreek(methi), fennel and licorice. The last two are glycyrrhizae, which is why they taste similar. However, it is also possible to initiate lactation merely by frequent physical stimulation of the nipples.

It is important to remember, as mentioned by DarklingAlice, that there are other factors that change how hormones are expressed in a person. Diet is also important, because of the ingestion of fats and cholesterols (cholesterol>>pregnenolone> steroid hormones) and also hormones from the meat one eats (especially these days) and flora. Fennel, for instance, was used by the... ancient Greeks if I remember properly, as a contraceptive. Though they killed off the species, current day fennel still holds up in clinical trials in avoiding pregnancy. Ginger is something called an emmenogue, because it can induce menstruation.

Hormones account for much of our emotional state, HOWEVER it should be noted that our personal mindset and conscious intention can change our emotional state, which in turn rebalances our hormones to support this new state. i.e, someone under a great deal of stress may fall into immune deficiency and adrenal burnout due to the physiological responses to long-term stress changing their hormonal output. Conversely, someone who tends to be slightly depressive and nervous with a low immune response can improve their condition by improving themselves mentally and emotionally, and the body will follow and support their new pattern.

[sexymomma]

Hello, I am new here, not yet approved and am just looking around and I might have a suggestion you can try. I am a psychology major, which requires loads of research. In my experiences with these types of topics, you should really try looking into peer reviewed journals and articles rather than wiki or med anything.coms. The reason for this, is that anything you read from these places has been reviewed by professionals, doctors, ECT.. Who have actually done projects, research, experiments, ECT. You can look up various journals online and search relevant topics, just be prepared for some language you might not get at first. Hope this helps.

[DarklingAlice]

A penny for the prospie ^_^ I can't agree more. PubMed is your best friend in inquiries like these.