Sexing the Body

Dr Fausto-Sterling,

Re the research you quote that sheds light on the origins and long-term effects of nurturing behavior in rats -- If applicable to humans, it would fit nicely with what's been written in the popular sexuality literature (e.g SexSmart by Aline Zolbrod - "How your childhood determined your sexual life, and what you can do about it").

Nature and nurture are inextricable in another way as well, even more so in humans than in rats: The young child's temperament calls forth positive and negative reactions from caregivers, depending on many factors including whether the caregiver has the natural capacity to handle a given temperament (some are obviously easier than others).

There's also the issue of the meanings that adult care providers assign to the child's particular temperament and innate behavioral repertoire. I recall when I was in training, one of my teachers, a celebrated infant researcher who was also a clinician, remarked that he'd often be asked to consult to a family about some troublesome behavior in an infant.

Very often, he said, the trouble was that one of the parents had identified the infant with a hated other ("He's acting just like my Uncle Joe did!") These irrational identifications were often a powerful determinant of the quality of "licking and grooming" the infant received, and the quality of "mirroring" and "validation" as well.

It's doubtful that rats react to individual pups as being "just like Uncle Joe." But in humans, infants' differences in temperament, the meanings that adult care-providers attach to them, and the adults' capacity to manage them (or not) probably contribute powerfully to emotional and sexual development.

It's not just what the parent brings to the interaction. It's also what the child brings, and whether the two are a good match or not.

Congratulations on your inaugural blog, and thanks again for this report on an interesting area of research.

Stephen Snyder, MD
Associate Clinical Professor of Psychiatry
Mount Sinai School of Medicine
New York City
www.sexualityresource.com
twitter.com/SexualityToday

not unlike wave particle duality in QM. Light [and matter] have both wave characteristics according to some experiments (dual slits etc] and particle characteristics in others: {single slit-photoelectric effects]. with the physical world being so malleable on the subatomic level (its not one or the other its both] why should not the biologic/ social domain share the same entanglements?

I don't see how your approach differs from the standard theory that genes and environment interact in complex ways to produce the behaviour we observe.

Thank you for the breakdown of this literature. Though the science is sound, I always worry about the social and policy implications of these models. I agree that moving beyond a false dualism is much needed, but I also wonder whether people will take this to support a social darwinist position that 'some other people' have bad health behaviors that need to be phased out. I guess I just hope that cognizance of the structural inequalities will make their way into the behavior science discourse, precisely because it is so compelling.

First, Thanks for your additions and questions. I plan to add more information to my initial entry so that over time my point, that the body is a dynamic system that never stops developing becomes clear.

Blindboy asks a valid question about how this differs from "the standard view". As he states the view in a very general way, most people would agree with it. But when you really dig in to how this all works, you will find than most people, including many scientists, really hold the view that genes form the blueprint, the complete human assembly diagram and that the environment can tinker with the details--making a window a little bigger or a little smaller. This is quite different from viewing the body as an indivisible system in which the matter of the body is constantly shaped by environment an experience. It is, perhaps (I have yet to find the perfect metaphor) like one of those impossible assembly diagrams that comes with your chosen piece of IKEA furniture. There is only one right way to assemble it, and you can overtighten or not tighten a screw sufficiently, but if you do it wrong, the furniture is wrong. Compare this to a Leggo set. Here you have hundreds of little building blocks and quite a variety of ways to assemble a structure.

Some molecular biologists have now abandoned the idea of DNA as a blueprint for development and instead consider the gene set we acquire at fertilization to be a toolkit (or, I would add, maybe a particular set of Leggo blocks); you still need to use the tools in the right way and have all of the needed specialty blocks to produce a functioning adult. And with the same tools and blocks, there is more than one possible outcome.

But more on this in future entries. In the meantime, thanks again for responding to my first effort.

I think what you are describing fits the notion of an interaction. An interaction implies that that factors are indivisible and that the outcome can only be understood in terms of how the factors interact. Thus the outcome is defined by neither factor but by their interaction. That is not to say that either or both factors do not have limits. Thus the impact that environment can have on the ultimate phenotype is limited by the nature of the genetic code in that individual. Similarly, the phenotype that a genotype can result in is limited by the nature of the environment that genotype exists in. The objection in this piece seems to be to genotype as a blueprint. If by blueprint we mean all of the instructions necessary to produce a specific phenotype, then a genotype is not a blueprint because the phenotype results from a genotype interacting with an environment. However, if by blueprint we mean a set of specifications that given the appropriate, or ideal, environment ( a talented builder for example, in the case of a building) produce a specific phenotype, then the genotype is a blueprint. Just a three different builders will produce three somewaht different buildings from the same blueprint, three different environments will produce three different phenotypes from the same genotype.

In an interaction between two facotrs both set limits on what the final outcome can be, but the final outcome can only be fully understood by the interaction of the two factors, and not by studying either independently from the other factor. I think that is the critical point about the interactionist point of view, which I am delighted to see is now seen as the common view. I would agree with that.

Kim