Depends on what you mean by "biological basis". If by basis you mean something like explanation or theory, well then it is obviously there in evolution. Heterosexuality is part of the mechanism for reproduction.. Tahir
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That was Charles Brown's question. Something along the lines, is hetersexuality innate?
>From the science point of view, I don't think we know, and trying to
think like a biologist, I not sure that's the right question to ask. I
say that because it sets the path of thought toward genetics and the
gene expression system for the underlying physiology.
You end up with what I think are absurdities in socio-biology like looking for a queer gene.
The path I would be interested in following tries to locate the brain control constellation that connects say various hormon systems and their production, and the general emotive affect.
There probably is some key location for what I am calling the emotive affect, because I've seen people who have had something like that part of their `personality' altered by brain damage.
I don't know enough neuroscience and brain physiology. It's probably what is popularly called `the reptile brain' or limbic system:
``Mammalian brain structure exists in the outer, most recently developed sphere of the brain, where evolution is newer and younger. These areas are the Limbic systems and neo-cortex. The Limbic system, which was first introduced by MacLean in a paper in 1952, is similar to the brain of the more primitive mammals and is the source of emotions, some aspects of personal identity, and some memory functions. The Limbic system is composed of the amygdala and the hippocampus. The neo-cortex, also known as the cerebral cortex, resembles the brain of more recent mammals in that it controls more highly evolved mentation such as reason and speech. Memory; the concepts of culture, art and literature; a prolonged childhood wherein learned behavior, vital to survival, is acquired along with generational recognition and care of family members are some of these more evolutionarily advanced brain activities which mammals have used to rise to such global prominence in so short a period of evolutionary time.
The brainstem and older, atavistic areas of the Central Nervous System control normal involuntary behavior that the conscious mind does not, such as the cardiac and respiratory functions. These are found in all vertebrates. In between these two brains, lies the R-complex.
The R-complex is named for the most advanced part of the brain higher mammals share with reptiles. It is responsible for rage[1], xenophobia[1], and basic survival fight-or-flight responses[1]. Often, the R-Complex can override the more rational function of the brain and result in unpredictable, primitive behavior in even the most sentient of creatures, humans included. A well developed and healthy neo-cortex can monitor R-Complex activity in sentient beings. The Reptilian complex is the most ancient part of a very successful brain scheme, evolutionarily speaking.''
http://en.wikipedia.org/wiki/Reptilian_brain
See what I mean by tone deaf? Looking at the limbic system from comparative zoology(?) and combining that with primate studies and then anthrology, the limbic system is probably also a foundation for a `social' view of animal behavior. This is getting near Wilson's socio-biology... another tone-deaf view. See I think what we should be looking it is a more gestalt view, the general forms of `the social complex' that social animals take on. Their sexuality is one of the basis of their social systems. Another of course is rearing young. And there are communication forms. No just signally, stances(?), but also smells, coloration, a bunch of different physiological feature that may not be directly connected to the limbic system either physiologically or genetically.
I think there might be somekind of feed-back loop going on where the social system is pushing evolution through genetics, by creating a natural selection pressure on the `herd', the gene pool of the particular social animals we see i.e. modelling and modifying the social system, selecting or not for this or that physiological feature through social means.
See this is how I think the study path leads into the question that Charles posed. But in another way, I am not sure quite how to deconstruct the concept of hetersexuality, break it down sufficiently to be able to link that concept or part of it to the above biological work.
This is actually were writers like Butler are really interesting. By questioning sex, gender, and body, she is doing a kind of anthropology, looking at the cultural imposition on a more neutral concept of body. I don't know how to put this... or where to go.
That's why I say get some of those postmodernists into the labs, open the damned sciences up here, boys. Mix it up and see what happens..