The tempting illusion of genetic virtue

M ark Walker has put forth a proposal which he calls the Genetic Virtue Program or GVP, whose kernel is that it is both possible and desirable to improve virtue by preimplantation selection or in utero engineering. Walker lists caveats to his thesis, although he consistently implies that their validity is doubtful by stating at each instance that he is including them ‘‘merely for the sake of completeness.’’ I will discuss the GVP from various angles of biology, my area of expertise. Personally, I’m in favor of genetic engineering freely undertaken for specific concrete outcomes; for example, adjustment to a radically new habitat. At the same time, as a research biologist I appreciate that even a small change will alter not only the attributes of the target but also additional processes and behaviors. Although Walker approaches the topic philosophically, there are so many errors in the scientific basis of his proposal that I find it hard to discuss them pithily. Analysis of the GVP is like elaborating Lysenko’s Lamarckian take on plant genetics or preparing a crewed expedition to Mars based on the Ptolemaic view of the universe. The most fundamental problem with the GVP is that there are no genes for virtue or even inclination for it, just as there are no genes for intelligence. Genes encode regulatory, catalytic and structural proteins and RNAs. They do not encode the nervous system; even less do they encode complex behavior. As one example, recent work out of the Plomin lab indicates that the six genomic regions defined by single nucleotide polymorphisms that contribute the most to IQ—itself a population sorting tool rather than an intelligence indicator—influence IQ by a paltry 1 percent. Walker further weakens his terminally wobbly foundation by invoking superceded genetics references that are a decade or more older and slipping back and forth between human and non-human studies. Rodent studies, in particular, are useless in illuminating causes of human behavior, since radically different foundations drive it in the respective species. About half of our genes contribute directly to brain function; the rest do so indirectly, since brain function depends crucially on signal processing and body feedback. This makes the brain/mind a bona fide complex (though knowable) system. This attribute underlines the intrinsic infeasibility of instilling virtue by changing ‘‘a few’’ genes, as the GVP proposes. Furthermore, although many diseases develop from malfunctions of single genes, this does not prove, or even indicate, that any single gene is responsible for a complex attribute. Instead a gene is the equivalent of a screw or a belt, whose malfunction can stop a car but does not make it run. The constant harping of the GVP on trait heritability ‘‘in spite of environment’’ is a straw argument. No serious biologist suggests (or has done so for a long time) that genes do not decisively influence outcomes. However, the nature/nurture debate has been largely resolved by the gene/environment (G 3 E) interplay model, a non-reductive approximation closer to reality. The genetic program is flexible and dynamic throughout our lifespan—we see this in the lab every day, even in homogeneous undifferentiated cell cultures. If genetic programs were as fixed, simple and one-to-one mapped as Walker’s article implies, we would have answered most questions about brain doi: 10.2990/29_1_76