Should-Read: Charles F. Manski (2011): Genes, Eyeglasses, and Social Policy

Should-Read: I think I have an answer to Charles Manski’s question “why does heritability research persist?” It persists because it is well-funded. It is well-funded because it makes some people feel better. It makes some people feel better because it can be read to reinforce white supremacy: Charles F. Manski (2011): Genes, Eyeglasses, and Social Policy: “Suppose that nearsightedness derives entirely from the presence of a particular allele of a specific gene…

…Suppose that this gene is observable, taking the value g = 0 if a person has the allele for nearsightedness and g = 1 if he has the one that yields normal sight. Let the outcome of interest be effective quality of sight, where “effective” means sight when augmented by eyeglasses, should they be available. A person has effective normal sight either if he has the allele for normal sight or if eyeglasses are available. A person is effectively nearsighted if that person has the allele for nearsightedness and eyeglasses are unavailable. Now suppose that the entire population lacks eyeglasses. Then the heritability of effective quality of sight is one. What does this imply about the usefulness of distributing eyeglasses as a treatment for nearsightedness?

Nothing, of course.

The policy question of interest concerns effective quality of sight in a conjectured environment where eyeglasses are available. However, the available data only reveal what happens when eyeglasses are unavailable.

Why Does Heritability Research Persist?… Given that it was widely recognized more than 30 years ago that heritability research is irrelevant to policy, I find it both remarkable and disheartening that some have continued to assert its relevance subsequently. For example, Herrnstein and Murray did so in The Bell Curve, referring to (p. 109) “the limits that heritability puts on the ability to manipulate intelligence.” Research on the heritability of all sorts of outcomes continues to appear regularly today. Recent studies such as the one by Cesarini et al. cited earlier tend not to explicitly refer to policy, but neither do they provide any other articulate interpretation of the heritability statistics they report. The work goes on, but I do not know why…