In lieu of an abstract, here is a brief excerpt of the content:The Uselessness of Polygenic Scores for Addressing Campus DrinkingBennett Knox (bio), HannahAllen (bio), and Stephen M. Downes, PhD (bio)Here we articulate a negative answer to Turkheimer and Greer’s question: “Is it possible to envision a genetically informed program that ethically intervenes on campus drinking?” (Turkheimer & Greer, 2024). However, first, we note that the authors cover an immense amount of ground in their paper. They lend insight (...) into how psychiatric genetics, at its very core, is conducted through their detailed examination of a large body of work in one specific area of this large field. A main result of this is to explain the gulf between results and conclusions, work that provides an invaluable service not just to various areas in philosophy and bioethics, but that are deserving of readership by a very wide audience. This gulf is explained via a careful accounting of the statistical measures used to assess the impact of genes on alcohol-related behavior in the college students sampled and comparisons between the strength of these measures and the strength and scope of conclusions drawn by the Spit for Science (S4S) researchers.A brief mention of the statistical measures in question helps set up our main focus. As Turkheimer and Greer note, before advances in sequencing technology, human behavior geneticists generated heritability coefficients for traits of interest. These coefficients were standardly produced from twin study work, which historically was the best way of getting a sense of the relative contribution of genes to a trait of interest as we cannot, or rather should not, conduct breeding experiments on humans. Current descendants of heritability coefficients come from genome-wide association studies (GWAS), which can be conducted on large groups of unrelated people. One key measure of interest arising from GWAS is a polygenic score (PGS), which “can be thought of as an observed manifestation at the individual level of the abstract variance ratio estimated by a heritability” (Turkheimer & Greer, 2024). Turkheimer and Greer focus on R2 values, which roughly “describe the magnitude of the relationship between the polygenic score and the phenotypes [of interest]” [End Page 437] (Turkheimer & Greer, 2024). They point out that the largest R2 reported in an S4S study is 6.5% (0.065). R2 are taken to be small at 0.01, medium at 0.09, and large at 0.25 in many areas of social science research but there are fields, for example, drug assay work, where only much higher R2 values are considered indication of a large effect. By this assessment, most of the R2 values reported by the S4S researchers, or calculated by Turkheimer and Greer when not reported, are very, very small, sitting well below the level of small effect of 0.01.Given these very low R2 measures, we agree with Turkheimer and Greer that S4S researchers did not uncover genetic information that could be informative, let alone actionable, for administrators concerned with campus drinking. However, it is worth asking what it would have looked like if S4S had produced such information. Suppose that S4S had been wildly successful, producing the Gattaca-like genetic information of “polygenic scores making reliable predictions that individuals had a 35% chance of developing a psychiatric disorder [here, alcoholism]” (Turkheimer & Greer, 2024). If a student was given their PGS, how are they to interpret it and act on it? How would this information be put to use by an administrator to address the problem of campus drinking?For the information to be leveraged at all, it would require consent from a significant number of students to have their PGS calculated and made available to themselves or administrators. Were scores to be calculated without active consent from the student (perhaps by using the sample provided to S4S), this would be a serious ethical violation. But even if a sufficient number of students did consent to having their PGS for alcoholism calculated, it is still not clear how this information could be used in an ethical manner to address the problem of campus drinking.If this student was already aware of a family history of alcoholism, then the PGS might do little more than quantify... (shrink)