  But notice the waffle words used by Watson and on the cover of Life: “in large measure” and “mostly in your genes.” Everyone is an interactionist these days, in some sense of “interaction.” Genes and environment, or nature and nurture, are recognized both to be necessary for development: by themselves, genes can’t determine or do anything. Yet, theorists still seem to give the nod to one or the other, suggesting that it is mostly genes or mostly the environment, mostly nature or mostly nurture, that make us what we are. This implies that it is possible to apportion the relative contributions of each. Gilbert (1992) suggests this in his dismissal of a more simplistic version of genetic determinism: “We must see beyond a first reaction that we are the consequences of our genes; that we are guilty of a crime because our genes made us do it; or that we are noble because our genes made us so. This shallow genetic determinism is unwise and untrue. But society will have to wrestle with the questions of how much of our makeup is dictated by the environment, how much is dictated by our genetics, and how much is dictated by our own will and determination” (pp. 96–97). However, the assertion that the relative contributions of genes and environment, nature and nurture, can be apportioned in this way is misleading if not outright false. As Lewontin argued in his classic paper on heritability, it is impossible to infer causal relations from the analysis of variance. The only legitimate exception is where there is “perfect or nearly perfect additivity between genotypic and environmental effects so that the differences among genotypes are the same in all environments and the differences between environments are the same for all genotypes” (1974, p.  408).[27] Contrary to Watson's assertion, the replacement of quantitative with molecular genetic techniques cannot resolve the nature-nurture controversy because of the same problem that affects heritability measures: the context-dependence of genes as causes given the nonadditivity of gene-gene and gene-environment interactions. Recent work in developmental systems theory (DST) which undermines any such attempts to apportion causal responsibility in organismal development makes clear why: traits are jointly determined by multiple causes, each context-sensitive and contingent (Griffiths and Gray 1994; Griffiths and Knight 1998; Oyama 1985; Oyama et al. 2001; Robert  2004).[28]