The unity of nature and nurture

Wednesday September 10, 2008

I wrote this essay as part of my application to teach English in Korea. As usual, being forced to write is not so far off from being forced to think, and I was generally pleased with how I formulated an idea that had been rattling around for a while. I think it could be better exposited at greater length, but here it's already over 500 words.

Prompt: "With respect to the nature versus nature debate, compare and contrast the roles of intrinsic and environmental factors in human development."

For some time it has been generally accepted that both nature and nurture play essential and intricately entwined roles in our development. Recent and current research attempts to specify only the extents to which genetic and environmental factors determine human outcomes. However, the historical understanding of the two sides of this debate as separate entities clouds an underlying unity. Analyzing the modern understandings of nature and nurture reveals a false dichotomy and motivates a choice in interpretation that emphasizes an internal locus of control.

Ridley's 2004 The agile gene: How nature turns on nurture gives an excellent exposition of how environments can interact with genetics rather than stand wholly apart. An individual's DNA and the systems that express specific genes form a massively complex system. Even with identical genes, certain traits may or may not manifest themselves depending on the environment an individual experiences. Contrariwise, studies of identical twins find that their genetics do determine in large part their adult traits - even when they live their whole lives apart - so the environment cannot be said to completely override genetics.

Modern medicine does make attempts to override genetics, as it were, by controlling the DNA developing into new humans. Prenatal testing is being used to determine whether a fetus will have genetic disease. Some tests are even designed to allow parents to choose whether their child will be male or female, and testing of this kind will only become more sophisticated. Men and women have always chosen their mates with some conscious or unconscious consideration for genetic fitness, but now engineered "designer babies" are moving from the realm of speculative fiction into reality. If we control nature, then nature itself is subsumed by nurture; the two categories collapse into one.

If we define nurture to be those circumstances under some measure of human control and nature to be not only genetics but any unchangeable element, it can quickly seem that circumstances of nature bleed into what we conventionally think of as nurture. For example, if a mother lives in a country wracked by poverty and famine, we cannot justly claim that the failure to nurture her child is her failing. The child born in this natural environment suffers malnutrition as surely as a child born with an extra twenty-first chromosome suffers Down syndrome. And the physical sciences constrict the range of circumstances in which humans are truly free to choose to a zero point. There is no room in science for free will, and if this is so then it is nurture eaten up by nature; everything is determined, nothing is chosen.

Pragmatically, then, we feel that we can weigh the benefits of two competing world views: either a deterministic universe in which everything is completely dictated by external circumstance and unfeeling physical law, or a world of self-made individuals cooperatively creating reality. From the former emerges helplessness and hopelessness. The latter promotes feelings of freedom, purpose, and self-determination. Presented with this ultimatum, it is more rational to operate as much as possible from the assumption that attempts to nurture our fellow humans are justified and meaningful.

This post was originally hosted elsewhere.