“Geneticism”: The Making of a New ism

I cringed a bit when I first saw this paper:

Nurtured Genetics: Prenatal Testing and the Anchoring of Genetic Expectancies

Any time there is mention of applying polygenic scores, particularly for so-called “educational attainment,” it raises my concern. However, I think this paper makes an excellent point that I’d like to explore further, about the perception of a “magical” genetics, fostered by decades of dubious claims purporting to demonstrate a role for genes for traits such as intelligence, personality, and mental disorders. I, of course, challenge any such role and chalk most of the ever-changing genetic correlations noted in studies to population stratification related to class, race, geography and other such divisions of people. Even if I am completely correct about this, however, there is an unfortunate reality created by these continued pronouncements of a genetic basis for something like educational attainment, noted in the paper:

1. Primacy Effect: Presenting polygenic scores for traits, as the first units of information about a child, will lead parents to assign undue weight to that genetic information.
2. Anchoring and Adjustment Heuristic: Parents informed about a future child's genetic predispositions (before birth) will form "genetic expect-ancies" (i.e., expectations created on the basis of polygenic scores), and will be less amenable to updating those expectancies based on subsequent environmental information compared to those informed post-birth).
   
3. Nurtured Genetics Effect: Parents will search to confirm or disconfirm their genetic expectancies and in doing so, they will be exposing their child to environments conducive to the actualization of their genetic expectancies.

Even if these polygenic scores are meaningless related to educational attainment (and, they are), they will still matter for educational attainment, because they will change the perception for individuals. This is not just for parents, but for the individual, who is now born with an expectation. If you don’t think you have the genes for getting a high level education, because you have been told this, then you are less likely to pursue higher education. If you don’t have the genes for “musical ability,” you might be less likely to pursue music, etc. So in, say, one or two generations, if these polygenic scores were widely used, you might essentially make the polygenic score valid, as people pursue what they are told by these scores to pursue and their parents guide them in that direction. 

I’ve pointed this out in the past related to psychiatric diagnoses, where it is often noted that a family history of a particular mental disorder will increase the likelihood that you will be diagnosed with that disorder. Well, sure, since psychiatrists are trained to give weight to family history when making a diagnosis, you would be more likely to get a particular diagnosis if your parent or sibling has that diagnosis than a person with the same symptoms who does not have a such a family history. So if you read that “studies show” that those with a family history of bipolar disorder are more likely to be diagnosed with bipolar disorder, it might take on a different meaning with this in mind.

Another concern would be if polygenic scores are accepted on an institutional level, where they are used to make decisions affecting the future of individuals. If this sounds like science fiction, Robert Plomin, a well known behavioral geneticist stated explicitly in his book, “Blueprint,” that, in the future, elite school selection should be based in part on “inherited DNA differences.” If such were the case, it would be a matter of time before people would take into consideration what DNA their potential spouse has and the likelihood that their children would have a high polygenic score for educational attainment.

In such a scenario, polygenic scores would reinforce classist and racist social structures, keeping those already more likely to get the benefit of a higher education locked in by their genetics, even if the genetic variants used to create a polygenic score have absolutely no real effect on a person’s ability to traverse higher education! This could create an extension of classism and racism, that one might call “geneticism,” that will be its own prejudice and compound other prejudices. Clearly, there is an incentive for those in a more privileged class to use polygenic scores to effectively help reinforce an aristocratic hierarchy and this is another example of the dangers of using polygenic scores for decisions relating to the future of individuals.

Study Shows That Genetically Identical Fish Can Have Lasting Behavioral Differences.

 This is an interesting study:

The Emergence and Development of Behavioral Individuality in Clonal Fish

 The study monitored the “behavior” of a specific clonal strain of a species of fish (Poecilia Formosa). They noted that, despite the fish all being genetically identical, they exhibited varying behavior (swimming speed, how active, etc.). 

Our findings show that substantial behavioral individuality is already present at the very first day of life after birth among genetically identical individuals, suggesting that pre-birth processes like pre-birth developmental stochasticity and/or maternal effects might play considerably more important roles in shaping behavioral individuality than commonly thought.

This variability only strengthened as the fish got older. From my perspective, the interesting thing is the extent to which this suggests behavior is not that defined by genetics, at least in fish. One might assume that this would extend to the more complex behaviors of humans, though, which begs the question as to how much influence genetic variants can have in human behavior for even one generation, much less be identified in genetically different individuals who merely share some common genetic variants. The math just doesn’t seem to be there for high heritability, if there is any heritability at all.

It would be interesting to see this experiment repeated with genetically varied fish and see if there is any more variation in their behavior (assuming they are physically the same size and shape, etc.) than you see with genetically identical fish. My guess is that it would be minimal.