Sexing the Brain: A Risky Proposition

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Biology 202

2006 First Web Paper

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Sexing the Brain: A Risky Proposition

Em Madsen

Imagine: one particular sperm with a certain je ne sais quois is chosen by an egg, and at that very moment of conception, the chromosomal sex of an individual is determined. This sex depends on whether the sperm contributes either an X or a Y chromosome to the egg's preexisting material. "If a Y chromosome is present, testes develop [from the bipotential embryonic gonad] and their hormonal secretions result in the development of a phenotypic male. If only X chromosomes are present, ovaries develop and the female phenotype results." (1) What does this mean? It means that even though chromosomal sex differs as early as conception, up until the seventh week of gestation, male and female fetuses are the same. "[These] "indifferent genitals" have a phallus, labioscrotal swellings, urogenital folds, and a urogenital membrane." (2) All humans begin with the same bodies, at least until that tricky seventh week. That's where all the trouble starts.

Part of the trouble stems from the fact that XX does not always a girl make, nor does the presence of a Y ensure a penis. Not only are there many chromosomal variations (such as XO or XXY), there are men and women who have the opposite sex's chromosomal arrangement (about one male and woman in 20,000). (1) Embarking on questions of sex and gender means that biologists and feminist theorists are building on already shaky ground. I mean, what to do about the chromosomal variations alone, never mind those individuals who are born male and undergo a sex-change operation after puberty to become the woman they always felt they were inside?

I began this paper with a discussion of the basic biological components of sex because both in class and in the larger world, debates about sex and gender depend on two major components, nature and culture. I wanted to briefly complicate the nature aspect: what humans see as immutable and inherent (biological sex) is often a very tangled and multi-layered affair. Understandably, culture is not exempt from scrutiny in this affair either. Biologists may study the male and female brain to better comprehend male's and female's strengths in various areas of reasoning. This process puts a lot at stake: what discoveries might there be, and how could this affect the war between the sexes. Would it be ammunition, or a subtle undermining? For these reasons, feminist theorists remain suspicious of biology, and tend to focus more on culture, which can be just as reductionist as giving primacy to the body.

Feminist/Quaker/Biologist Anne Fausto-Sterling describes the split between biology/nature and feminist theory/culture as follows: "Molecular biologists rarely think about interacting organs within an individual body, and even less often about how a body bounded by skin interacts with the world on the other side of the skin." (3) In addition, "Unlike molecular biologists, ...feminist theorists view the body not as essence, but as a bare scaffolding on which discourse and performance build a completely acculturated thing." (3) So how can these two groups effectively talk to one another and do good theory and good science? Fausto-Sterling presents a third approach to the study of sex and gender which seems to me to be a good option. This new way of thinking both acknowledges the shakiness of nature's and culture's standpoints, and allows for the richness and complexity of the subjects to thrive. She writes: "Developmental systems theorists deny that there are fundamentally two kinds of processes: one guided by genes, hormones, and brain cells (that is, nature), the other by the environment, experience, learning, or inchoate social forces (that is, nurture)." (3) Her main example of this new way of thinking is as follows: a goat loses its front legs after it has been born. As a result, it learns to hop around on its back legs. When the goat dies, scientists realize that this repeated action has resulted in a huma-like S-shaped spine in the goat. This S-shaped spine was shaped neither by nature or culture, but through a subtle combination of the two, as well as atmospheric conditions and factors which do not fall in either camp. As a feminist myself, I find this school of theory to be a refreshing change. It does not limit discourse to the body, nor does it make the body into a performance site. What it allows for is space. This is valuable and needs to be preserved at all costs in the study of sex and gender. When we press our faces too close to the subject, we often cannot see anything at all.

For this reason, I find the study of the brain in regards to sex is a territory that is fraught with danger. Unless scientists and feminists alike can utilize the developmental systems theorists' models, or similar manners of thought, the issue will remain a dichotomy, and little or no progress will be made. And while biologists can study the brain and let the public know that an androgenized brain shows little behavioral response to estrogen, while in male brains this suppresses the lordotic response while eliciting it in female brains, (1) this is only part of the picture.

As Fausto-Sterling points out, study of the brain even when not gender/sex-specific is difficult. "To prepare the brains [for examination], one must pickle them... Different laboratories use different... methods, and all methods result in some shape distortion and shrinkage." (3) Also, by concentrating exclusively on certain areas as a source for sex differentiation, such as the corpus callosum, biologists actively ignore the interconnected functioning of the brain itself. "The winter of 1992 was a hard one... Newsweek and Time magazines started the trend by running feature stories about gender differences and the brain. Women, a Time illustration informed its readers, often had wider corpus callosums than men." (3) Again, this is a dangerous proposition. I'm not saying that it is a mistake to study the brain, I am just saying that it needs to be done in a more integrated manner. Developmental systems theories would argue for a wider camera-angle to be placed before the brain, with a thorough examination of many aspects of the individual's life and functioning, not only the nanometers involved in the corpus callosum. The danger of using a telephoto lens is explicitly shown in Werner Herzog's film The Enigma of Kaspar Hauser (1974). Hauser, an unusual man who is raised without learning how to speak or write, dies and is subjected to an autopsy. At the conclusion, the doctors observe that there are abnormalities in his brain. They determine that Hauser's strange behavior in life must stem from these abnormalities. In the process, they completely ignore the fact that the first 25 years of his life were spent in isolation, language-less and lonely.

Theory does not exist in a vacuum, however, neither does science. Not only should developmental systems theories be at the forefront of any future work in sex and gender in both biology and feminist theory, there must be a fundamental examination of the perpetuants of the biological and theoretical work. Aren't they just as much a part of the system as the subject? I've revealed myself to be a feminist, so take this as you will--perhaps with a grain of salt. However, I do believe that biology and feminism have a lot to learn from each other, and neither is blameless in what has been a historical fear and loathing. It's time to lay those past dichotomies aside and engage in a more active and comprehensive look at what these systems humans both partake in and build mean in terms of future discoveries.

1) Kandel, Schwartz, & Jessell. Principles of Neuroscience. Appleton & Lange, East Norwalk, CT. 1991.

2)Child Physiology: Genital Development web site, There's a really cool interactive diagram here, too.

3) Fausto-Sterling, Anne. Sexing the Body. Basic Books, New York, NY. 2000.

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