The genetic lottery why DNA matters for social equality The genetic lottery why DNA matters for social equality , by Kathryn Paige Harden, Princeton, Princeton University Press, 2021, 312 pp., $29.95/£25.00, ISBN: 9780691226705

Click to increase image sizeClick to decrease image size Notes1 In human behavior genetics, heritability is usually calculated by comparing the similarity of monozygotic (identical) twins to that of dizygotic (“fraternal”) same-sex twins, under the assumption that such sets of twins will have experienced (roughly) the same developmental environments, and so any excess similarity in identical twins must be associated with their excess genetic similarity. For a critique of this methodology and the assumptions underlying it, see e.g. Joseph, Citation2014. While I am skeptical of the accuracy of heritability estimates in human behavioral traits (see Matthews & Turkheimer, Citation2022 for a review of some of the ways in which heritability estimates can be inaccurate), my own view is that the concept’s fundamental limitations usually make arguments about its accuracy moot (see Kaplan, Citation2006, for discussion).2 I want to note that I am not endorsing such a policy – while I would like to be in a society in which everyone remotely capable of doing so and with any desire to do so be able to attend and graduate from college without incurring unreasonable costs, I don’t think it is imperative that everyone capable of doing so in fact want to do so, and would hope that any reasonably just society would create / hold space (meaningful, well-paid work) for people for whom pursuing a college education was not attractive.3 Though again, Harden overstates her case. The evidence suggests that children who are more genetically similar to children who engage in early sexual behavior (within a particular social context, etc.) are also more likely to be similar in terms of adverse outcomes, but the move from there to “genes that accelerate reproductive development” is a stretch, at best.4 I resist citing this “paper” as doing so risks legitimizing it and the “journal” in which it appears – readers interested in reading this “paper” will I trust have no trouble locating it.