Yes, But….
“However physical differences in adults may be due to psychological and sociological pressures on the brains of each gender, because cultures and societies may exaggerate roles and stereotypes, having an impact on brain plasticity. “

Where’s the data? This is a plausible hypothesis, and I’d be astounded if it were not true to some degree.

But… different regions of the brain have different degrees of plasticity. Some appear invariant regardless of post-natal environment, barring gross physical trauma.

I think we must draw a distinction between the areas of “gendered behaviour” which are post-natal, and which are innate.

Recommended Reading (all available online)

Sexual Hormones and the Brain: An Essential Alliance for Sexual Identity and Sexual Orientation Garcia-Falgueras A, Swaab DF Endocr Dev. 2010;17:22-35
e.g.
“Alexander and Hines [2], who offered dolls, toy cars and balls to green Vervet monkeys found the female monkeys consistently chose the dolls and examined these ano-genitally, whereas the male monkeys were more interested in playing with the toy cars and with the ball….”

Biased-Interaction Theory of Psychosexual Development: “How Does One Know if One is Male or Female?”  M. Diamond, Sex Roles (2006) 55:589:600

e.g.
“A theory of gender development is presented that incorporates early biological factors that organize predispositions in temperament and attitudes. With activation of these factors a person interacts in society and comes to identify as male or female. The predispositions establish preferences and aversions the growing child compares with those of others. All individuals compare themselves with others deciding who they are like (same) and with whom are they different. These experiences and interpretations can then be said to determine how one comes to identify as male or female, man or woman. In retrospect, one can say the person has a gendered brain since it is the brain that structures the individual’s basic personality; first with inherent tendencies then with interactions coming from experience. “

Male-to-female transsexuals show sex-atypical hypothalamus activation when smelling odorous steroids by Berglund et al Cerebral Cortex 2008 18(8):1900-1908;

Male:to:female transsexuals have female neuron numbers in a limbic nucleus. Kruiver et al J Clin Endocrinol Metab (2000) 85:2034:2041

Sexual differentiation of the human brain: relevance for gender identity, transsexualism and sexual orientation. Swaab Gynecol Endocrinol (2004) 19:301:312.

A sex difference in the human brain and its relation to transsexuality. by Zhou et al Nature (1995) 378:68:70.

A sex difference in the hypothalamic uncinate nucleus: relationship to gender identity by Garcia-Falgueras et al Brain. 2008 Dec;131(Pt 12):3132-46.

“We spoke for 2 1/2 hours on why cross gender identity was a normal inherited variation of humans. We showed how Transgender Brains think, smell, and hear like the opposite sex.”— Prof Sid Ecker, private correspondence, available at http://aebrain.blogspot.com/2009/05/brain-gender-identity-presentation-by.html

Looking at sex differences that are due to differences in androgen:estrogen ratios is misleading. Differences in androgen:estrogen ratios are caused by subtle variation in hypothalamic gonadotropin releasing hormone (GnRH) pulsatility.  The GnRH pulse is generated from the medial preoptic area of the anterior hypothalamus, which is where Simon LeVay noticed differences that seem to vary with male sexual orientation, where Dean Hamer suggested the X-linked “gay” gene would exert its effects, and where putative human pheromones seem to shed light (literally, with brain scans) on orientation variability in the response to social odors from males or from females. At the same time, most people look at sexual preferences as if the automatically exist in the absence of any developmental pathway, despite full knowledge available on the levels of biological organization that allow mammalian pheromones to activate early gene expression in GnRH-secreting nerve cells of brain tissue: the required gene-cell-tissue-organ-organ system link from the social environment (nurture) to genetically predisposed behavior. Most people recognize that their food preferences develop through exposure to the chemistry of food. How many more years might it be before they recognize that their sexual preferences develop through exposure to the social odors (e.g., the pheromones) of other people?
see for review http://www2.hu-berlin.de/sexology/BIB/kohl.htm

There are more than two options (binary gendered, non-gendered). Will gender multiply?

We have (unfortunately only) anecdotal evidence that about 1 in 3 transsexuals change sexual orientation during transition. While most tend towards the norm for the target gender, the same ratio of cross-sexed preference as in the general population results, we think.

We also have anecdotal evidence of rapid changes in osmic sensitivity immediately following high estrogen levels, either administered therapeutically or from natural causes.

Designing experiments is difficult.

A fruitful research subject would be the psychology and neuroanatomy of those with 5alpha-reductase-2 deficiency and 17beta-hydroxysteroid dehydrogenase-3 deficiency. Such conditions result in a somewhat female appearance at birth, with masculinisation later in life. This can vary from a very masculinised female appearance only masculinising slightly, to an apparently normal female appearance masculinising completely. There is no evidence of neurological change, so this situation can either cure or induce gender dysphoria - transsexuality, essentially.

Cohen-Ketternis did some work on this, but more needs doing.

Arch Sex Behav. 2005 Aug;34(4):399-410.
Gender change in 46,XY persons with 5alpha-reductase-2 deficiency and 17beta-hydroxysteroid dehydrogenase-3 deficiency. - Cohen-Kettenis PT.
http://www.ncbi.nlm.nih.gov/pubmed/16010463

I’m too close to the issue, being one of the rare cases of dichogamous female pseudohermaphroditism. The biological mechanisms involved in such cases are not well understood: there appears to be 6 different etiologies involved, but when n=30 including all recorded cases worldwide, sample size is too small. n>5000 for both 5ARD and 17BHDD, so these are better experimentally.

Psychologically speaking, I’m indistinguishable from a standard case of transsexuality. But about 1 in 3 have transsexuality induced, not cured, by such conditions, the same ratio as with 5ARD or 17BHDD.

I can speak from personal experience that the hormonal changes and resultant disorientation are profound for the patient. Objective evaluation “from the inside” as it were is not feasible.

An encouraging article. This is the sort of thing I want to see from technoprogressives and transhumanists. However, your usage of the word “gender” conflicts with my understanding of the term. In feminist theory, gender is the social category while sex is the biological. Socially, I assure gender remains alive and well. Because it’s central a global system of oppression, it won’t be going anywhere without a struggle. I suggest revolution.

Will gender exist 100 years from now, or does it already not “exist?”

In my opinion, it will exist, with the same sort of 98+% surety as it does today, and as it did 2000 years ago.

Say there might be a planet for those who want hetero-sex; a planet for gays; another planet for posthumans who don’t even know that gender & sex exist; a planet for fundamentalists who want no sex, a planet for fundamentalist who want sex for reproduction only…

veronica and postfuturist, your both totally off base in understanding what this article is about.  Today, as this is written science, especially brain science keeps showing who ambiguous our brain’s can be when it comes to stereotyping and brain dimorphism.  The science that is out there suggests that the phenotype - the visible phenotype of a person does not totally go along with the phenotype/genotype of ones brain when it comes to sex or gender.  The fact that science is able to start explaining exaggerated gender roles and sex is what I am trying to get across.  The science is out there, the research is both done and continuing, and humans are on the brink of self-genetic engineering.

I have derived this, which may help you in your research 😊
http://fav.me/d2q34dc

“The science that is out there suggests that the phenotype - the visible phenotype of a person does not totally go along with the phenotype/genotype of ones brain when it comes to sex or gender. “

I agreed with this. It does not “totally” go along. But it does probably about 98% of the time.

Very nicely written.
However, Kris, I cannot help but wonder why you would like this gender difference to be erased; I think the human species has other more important problems than this.
I’m thinking it might be helpful to try and control the effect that hormones can have on the dopaminergic system for ex. (but many people are already trying to do that), perhaps we would then be able to be more efficient and develop a bigger prefrontal cortex, with better connectivity?
I think both men and women get affected by hormonal disbalances, and this would be a nice thing to control in, say, people who are doing mathematics or engineering or anything that involves rational thinking.
I would not want to erase the gender difference though. Besides, the balance is extremely complex: genes, environment, neural architecture. I think we have a long way to go before beginning to grasp how far this balance goes and what happens if you toy around with it.

Kris, my comment was a joke—a bad one. But your observation “From this we can conclude that the gender identity listing in the current Diagnostic and Statistical Manual of Mental Disorders should be eliminated” is the most interesting of all. Rhetorically inquiring: how much else in DSM ought to be eliminated?

Diana : I believe that the “gender line” will be “erased” in the next century. I agree that we have a while until we fully understand the genetics, neuroscience, and nurture components of sex/gender.  However while I say that, there is a lot of data that is already out there suggesting that gender is extremely diverse - more then most of us think. The future science I believe will continue to show this point. There are so many things we need to fix as a species, but this issue will evolve on it’s own and will continue to the point of “erasing”  the gender line.

Postfuturist : from the research I have done on this topic it seems that that the LGBT community does in fact want “Gender Identity Disorder” taken out of the DSM.  There are those who want to keep it in the DSM because of the benefits that go along with it.  Calling it a “disorder” however is totally unnecessary.

I would have responded to this post days ago but I apparently got banned by accident.

@Zoe, I would love to talk with you further about the science of TG, because I am a MtF with primarily female orientation, which resulted in my doctor refusing to classify me back in the 90s, and refusing me treatment.

@ Summer, I don’t think gender will ever disappear, but once it is a matter of choice, not a sentence, I think the concepts of sex superiority will just lose all basis and fade away.

“Postfuturist : from the research I have done on this topic it seems that that the LGBT community does in fact want ‘Gender Identity Disorder’ taken out of the DSM”. Agreed, but what else, of a non-gender related nature, ought to be eliminated from DSM? how much of what is called mental illness is in actuality exacerbated PTSD? It is mostly a rhetorical question as this is not the forum to go into it nor can it be answered simply. Still, a discussion of arbitrary diagnosis in DSM brings this immediately to my mind, as it may be the largest issue.

Valkyrie, what purpose would the gender distinction have in a world with morphological freedom? Today, for example, we rarely feel the need to sort people in fundamental classes based on eye color.

You are misinterpreting me Summer. I said gender will exist, but be unimportant.  Pretty much exactly like your eyecolor example.

People will probably still chose to be male or female, some will chose to be both, some will chose to be neither, some will chose to have some new possibility that we haven’t invented yet.

But choosing to have a gender as opposed to having one forced on you is far different. Sure at first there will be parents seeking to force children to be one or the other, but since that choice does not have to be permanent the sole factor that will eventually matter is individual preference. Some people will prefer to look female, and have female bodies, others will choose to look male and have male bodies, but no-one will have “Gender roles” in larger society, and various enhancements will eliminate the strength differences or other “gender advantages/disadvantages”  usually touted as a basis of gender discrimination, and “maleness/femaleness” will become a matter of mental self image, and thus open to the full spectrum of human variation between the two, with the usual bell curve.