- In Chapter 4 of Sex/Gender: Biology in a Social World, author Anne Fausto-Sterling explores the potential role of prenatal hormone exposure in behavioral differences between men and women. What conclusions does she come to, and what are the implications of those conclusions?
2. In the first section of Chapter 3 of Fausto-Sterling's "Of Molecules and Sex," what exactly is the author's point in describing (in detail) the sexual and reproductive practices of fish?
Anne Fausto-Sterling, author of Sex/Gender Biology in a Social World, is the Nancy Duke Lewis Professor of Biology and Gender Studies at Brown University. Her work focuses on gender differentiation and is widely referenced in feminist and scientific publications. Her aim is to restructure how science and the general public, part of her focal audience, understand the impact of nature/nurture influences. For her, the dichotomous, two-sides, male/female discourse of gender is expanded under the recognition of the inseparability of nature and nurture, so inseparable that "cultural differences" become "bodily differences": She asserts that the expression of sex/gender is critically impacted by the social world from the earliest moments of life.
Fausto-Sterling states that the idea of brain sex has developed such a "cultural valence and resonance" that mounting biological fact is not enough to shake its entrenched hold in the minds and understanding of individuals in Western cultures. She offers many avenues of proof to disable this cultural conception. In Chapter 4, "Of Hormones and Brains," she provides several classes of studies, including mice, canaries, rats and humans from which to mount her presentation of facts that counter the concept of brain sex, defined as a sexual orientation dominating the structure and the biological and neurological functions of the brain.
She discusses the epigentic modification of genes called imprinting in which genetic information is temporarily suppressed (not representing gene mutation). Suppression of maternally or paternally contributed genes varies in embryo and adult phases of life. One study explored such imprinting in mice. In embryonic mice, maternal dominance over suppressed paternal genetic information was expressed. In adult mice, paternal dominance over suppressed maternal genetic information was expressed. Fausto-Sterling concludes that this finding complicates the simplistic idea that "fetal hormonal sex produces or causes brain sex differentiation."
One of the most impressive studies she discusses is the 1980s work by experimental psychologist Janice Juraska who compared the brains of rats. Some of the rats were reared in the traditional Isolated Condition (IC) and some were reared in an innovative Environmentally Complex (EC) condition designed by Juraska.
Those reared in the IC method lived and ate in separate cages from each other with little stimulus beyond their own movements. Her measurements of the neurological complexity expressed in their hippocampuses showed males had much more complex neurological development as measured by the presence of synapses and synaptic bundles.
Those reared in the EC method lived in single-sex group cages in which new toys were placed daily, after the previous day's toys were removed. Her measurements of the neurological complexity expressed in their hippocampuses--after living in richly complex environments--showed females, not males, had much more complex neurological development as measured by the presence of synapses and synaptic bundles.
Whether this result can be applied to human brains is still to be fully answered because of ethical constraints on experimentation with humans, but this result does underpin Fausto-Sterling emphasis on the inseparability of nature/nurture and her insistence that cultural differences become bodily differences.
Her conclusion is that the concept of brain sex is unsound and that the true concept sex/gender is a complex one that science has only begun to reveal. This is not contradicted by anatomical studies, such as the canary study, that indicate there are anatomical differences in some male/female brains since her assertion is that sex/gender is a product of a composite of biological functions, including neurological, genetic and anatomical.