 Part of what is at stake between followers of Lewontin and Sesardic is whether or not \(V_{GxE}\) and other components of variance are negligible or significant. This issue is not purely philosophical and can and has been tackled experimentally. Tabery (2009a and 2014) draws attention to a longitudinal study by psychologists Caspi and Moffitt, who show GxE effects in a longitudinal study of human anti-social behavior disorders, in support of a view in line with Lewontin’s. Douglas Wahlsten also pursues this issue in much of his experimental work (Wahlsten 1990 summarizes his theoretical views and Wahlsten and Gottfried 1997 is a good survey of some of the relevant experimental work on animals).  Further, understanding gene-environment covariance, \(\COV(G,E)\), as part of heritability has led some to incorrectly attribute environmental effects on phenotype to genes.  Dickens and Flynn (2001) use an example of basketball playing ability, which they label BP, to make this point.  They argue that if we assume that BP is highly heritable, there still appears to be a large environmental component to BP.  On their account, this makes sense is we take gene/environment covariance seriously.  Just as our tall plants, in Section 2. above, can end up in nutrient rich environments that shorter plants do not, tall, athletic individuals are often placed in environments that enhance their BP. As Dickens and Flynn point out, identical twins who are tall and athletic, including those separated at birth, could have parents who play basketball with them or could be placed in basketball training regimens in school or college.  In these situations each individual's BP would increase but it is wrong to attribute this increase in BP to genes for height and athleticism, since the relevant environment has a significant influence on the phenotype. 