Remember XYY

Sophia Siedlberg


Issue 16
Winter 2001

It has often been cited that men are aggressive because of "the Y chromosome" and that, as such, women who carry the "Y" chromosome are really violent men pretending to be women. Not helpful for a teenage girl who has CAIS, Swyers, 5 alpha reductase deficiency or PAIS. In fact very damaging if they don't identify as male.

The point of course is that this kind of assumption keeps re-asserting itself, justifying that old notion that XY =Male. Given that surgeons are now perfecting the procedures of phalloplasty on intersex children, who may not want this, there is serious cause for concern.

A few years ago there was a terrible situation where men identified with having a mosaic condition where they inherited two "Y" chromosomes were subjected to harsh pathologisation on the part of the medical profession, so much so that boys identified as having this condition were in some cases incarcerated because they "Posed as significant risk to society" Is this mistake to be repeated, only on a group of women this time?

My guess would clearly be yes. But before the media makes a meal of the old XY ="male pseudo hermaphrodite pre-disposed to violence lock her (oops sorry) - him up and throw away the key" routine, let us for a moment consider what is being said.

The latest article, produced by the American Physiological Society"Sex Differences in Brain Monamines and Aggression,"is one of a large volume of articles put out by the APA - I suspect with the sole aim of making it clear that there are two sexes, and that anything that does not "fit" the mould is "not normal" It is the impression that one is almost forced to have considering both the bulk and the somewhat deterministic line being adopted here. The question I ask is why?

For the purpose of clarification, I have taken this particular article to examine in more depth simply because of how it will inevitably impact on a large patient group who already suffer some degree of clinical mismanagement, malpractice and social stigma. The abstract is as follows.

"Sex Differences in Brain Monamines and Aggression,"
by Jonathan Toot, Gail Dunphry, and Daniel Ely, from the Department of Biology, The University of Akron, Akron, Ohio.

"Methodology and Results
"Resident intruder" tests were used to measure the aggression and stress of male and female rats. In a colony of male and female rats a hierarchy is established, with male rats assuming a dominant role over the female rats."

Nothing new here, basically this model is often applied and often is seen to contradict the real life situations it is applied to in the case of human beings.

"Different male and female rats were then introduced into the established colony. Male intruders were attacked 2.6 times and received 1.8 scars over 15 minutes. Female intruders were not the perpetuators or recipients of any attack."

In previous articles I have written I have often been quite damning about this reasoning. The reasoning to justify this model is even more contradictory.

"Norepinephrine, dopamine and serotonin were measured by high performance liquid chromatography (HPLC) in various regions of the brain including hypothalamus (VMH), media amygdala AME), lateral amygdala (ABL) and hippocampus (HPC). Norepinephrine content of VMH, AME, ABL, and HPC was not statistically different between the two sexes. However, values of dopamine in ABL of males were significantly less than corresponding female rats; levels of serotonin in the AME and ABL were also less in males compared to females."

So how is it then that human females are more prone to migraines? The genesis of which involves this very mechanism? Also where is there mention of the "Y" chromosome?

In males, decreased serotonin in the amygdala was associated with increases in aggressive behavior. Whether this relates only to the presence of the Y chromosome or to a combination of the Y chromosome and male hormone testosterone, remains to be determined."

So why then is the media hopping on the "Six pack SRY in Y" bandwagon again? This is just too easy for me to dismantle to be perfectly honest. What is the basic genetic argument here? I don't see the link. I can look at all the "Virilising genes" that have to date been sequenced and have yet to find any in the Y chromosome that are involved in coding for the production of, enzyme activity involving, or affecting of any of the compounds mentioned. Please enlighten me? Also how is it that serotonin in human females is often lower, giving rise to migraines. If this is more common in women what is the study driving at? Also they discuss the Amygdala. OK this is sensitive to steroidal hormone activity during fetal development. The lack of steroidal compounds of a certain type often leads to cellular apoptosis with respect to nerve cells. Can someone explain whether or not this has been covered in the study.

Am I to be critical of the study itself? Well in part no! Because the observed levels of serotonin do seem to be of interest to me with respect to "sex differences" My problem is the almost arbitrary association of this with the "Y" chromosome, and the way the media have produced headlines claiming that the "Y Chromosome makes men (And I assume XY women) into criminal psychopaths" The authors of the study have not clearly stated that "Y" ="Psycho" The study has observed a colony of rats and has found something quite interesting with respect to serotonin activity in the dimorphic model of male and female rats. which actually contradicts human models of the same. If I may re-quote . . . .


I can only state that while the Study intrigues me a little, and I would be interested in reading the full paper, the media reaction is a perfect illustration of the irresponsible handling of scientific subjects by the media.

As far as I am concerned any media interpretation that claims that any of this is connected with "Y" chromosomes, and tries to justify that stance, is basically lacking in any fundamental understanding of the science involved. This time the media have made fools of themselves.

As for the APS, I am still asking the question why is it so important to make such stark divisions between the two sexes considering the way intersex people, and transsexual people as well for that matter are going to suffer more clinical pathologisation and inappropriate, debilitating medical approaches and practices because of it.

Other articles by Sophia Siedlberg:

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