Nature V Nurture

I found an artilcle by Wasserfall, Nead, Matthews, and Atkinson (2011) that, while attempting to present an hypothesis that might predict the effect of nature and nurture in the onset of Type I diabetes, actually provided a reasonable rationale for the difficulty in separating the two forces. The authors point out the gains made in understanding genetic contributions and environmental contributions but difficulty in determining the strength of individual forces responsible for each. Given the complexity of human genome, and the recognition that human genes often control multiple factors, it is likely that we will never be able to distinguish precisely the effect of nature or nurture in the expression of genes.
This to me was a much more satisfying explanation than the one provided in Article 1 of this week’s resources that said that intelligence in separated twins was not an effective example of nature v nurture since separated twins “chose more similar social environments than siblings would have, and thus they had more similar IQs”. This seemed an odd statement since left to their own devices, there is no evidence that a child placed for adoption would seek out a specific type of parent nor is there evidence that a specific social class of parent is more likely to adopt. Finally, no evidence was provided that these separated twins were making these specific social environmental selections later in life or that they had not been taught to do so.
The primary reason, in my estimation, that nature v nurture cannot be determined, is that we and the society we live in are so complex. We cannot derive an experiment that is capable of limiting the variables to one gene or one environmental factor. Until we do, this debate is not likely to be satisfied.

Wasserfall, C., Nead, K., Matthews, C., Atkinson, M.A., (2011). The threshold hypothesis: solving the equation of nurture vs nature in type 1 diabetes. Diabetologia, 54(9)2232–2236. DOI 10.1007/s00125-011-2244-z.