Book Review: The Societal Impact of Genetic Research

Genetics is rarely as simple as introductory biology classes make it seem. Only some biological traits, such as blood groups or dry ear wax, are linked to a single gene and passed on in the predictable way that Gregor Mendel demonstrated with pea plants in the mid-19th century. Instead, many traits are a complex effect of multiple genes in combination with other factors. For example, even though some people are genetically predisposed to be at a higher risk of heart disease, their health outcome also depends on their lifestyle and health care access. But if it’s already difficult to predict whether someone will develop heart disease based on genetics alone, imagine how much more nebulous it gets when genetic test results are linked to social or behavioral outcomes.

In “What We Inherit: How New Technologies and Old Myths Are Shaping Our Genetic Future,” Sam Trejo and Daphne O. Martschenko outline the complex relationship between genetics and societal issues. The title refers both to genetic inheritance and to two persistent genetic myths that have been passed on through generations. One is the destiny myth, which assumes that genetics alone can fully explain differences between people. The other is the race myth, or the belief that there is a genetic basis for the way that society has categorized people into races.

BOOK REVIEW — “What We Inherit: How New Technologies and Old Myths Are Shaping Our Genomic Future,” by Sam Trejo and Daphne O. Martschenko (Princeton University Press, 272 pages).

The book includes historical examples of these myths in action, like the Supreme Court’s 1927 Buck v. Bell ruling, which allowed for the sterilization of people with intellectual disabilities. Underlying this decision was the destiny myth: the strong belief that parents passed on learning disabilities to their children. The destiny myth often goes hand in hand with the race myth, which has led to cases of forced sterilization of racial groups, and to several terrorist attacks motivated by a fear of White people being “replaced” by other ethnic groups.

These myths have also permeated society in less violent ways, such as through teachers making the assumption that some students are inherently capable of doing well in school while others are not. Martschenko adds her own experience of being treated differently at school depending on whether teachers had met her Black mother or her White father.

Genetic research has brought the destiny myth and race myth to the forefront in a new way. By looking at large groups of people and their DNA, researchers have been able to express outcomes linked to a complex interplay of multiple genes as a polygenic risk score.

These scores can be used to estimate health outcomes, but they are also used in sociology research. For example, polygenic scores have been calculated for educational attainment — a measure of how many years of schooling someone has had. Comparing school records with the genetic profiles of thousands of people generates a number that describes a link between genes and schooling. But, as Trejo and Martschenko point out, polygenic scores do not just include genetic information. “The effects of DNA operate by means of the social and physical world, and phrases like ‘genetic effects’ or ‘effects of DNA’ can obscure the fact that there are often many environmental links that exist in the causal chain,” they write. Even a score for a health outcome like diabetes or heart disease will include societal factors related to health care access, for example.

While genetic research can be used to carefully tease out how societal factors and genetics interact, Martschenko and Trejo warn that genetic research also feeds into existing genetic myths. Academic papers about the genetic lactose tolerance of Europeans are already cited online by people who proudly proclaim that they can drink milk, linking the race myth to White supremacy. And an existing belief in the destiny myth can be further strengthened by seeing that researchers have calculated polygenic scores for things like intelligence or educational attainment.

Trejo and Martschenko carefully balance both sides of this equation. Trejo is a sociologist who uses genetic research to study how biology and sociology interact. Martschenko is a bioethicist specializing in the responsible use of genetic information. It’s a perfect combination of expertise to address all angles of the issues, and the pair wrote “What We Inherit” in a way that highlights their differences in a conversational dialogue format.

Through these dialogues and examples scattered throughout the book, we get to know the authors beyond their professional lives. We learn, for example, that Trejo donated a kidney and that Martschenko was a competitive rower in college. Such stories are used to illustrate topics like social inequality or destiny, but they also make for an accessible read.

 

However, the main purpose of the dialogue sections is to show where the authors offer distinct perspectives. In the preface, they reflect on discussions they had when they first met at a conference. “Those early conversations fooled me into thinking our disagreements would be simple and straightforward,” Martschenko tells Trejo. “I would be the critic of new genetic technologies and you, the enthusiast.”

In a dialogue later in the book, Trejo and Martschenko reveal that their discussions about social inequality were some of their “most difficult conversations” because they each had a very different understanding of what the term “social inequality’’ means. Martschenko equates the term with structural inequality linked to race or class. To Trejo, the concept is much broader and includes any difference between humans, some of which were relevant to genomic studies. Once they identify their different interpretations of social inequality as the source of many of their misunderstandings, their voices become more aligned.

In the last few chapters, the authors’ voices are indeed more aligned as they look to the future of genetic testing. They describe how prospective parents might use polygenic risk scores in combination with IVF treatments to select babies with less likelihood of contracting heart disease later in life. But without proper regulation, this could also lead to eugenic selection for other traits — especially if people keep believing the destiny myth.

Trejo and Martschenko suggest a set of guidelines for polygenic embryo selection, starting with “a complete moratorium” in the short term and only allowing some traits to be selected after quality reproductive care is accessible to everyone, to avoid further systemic inequalities. They further consider the risks of polygenic prediction in the hands of individual consumers, recounting the example of a couple who took matters in their own hands and uploaded their IVF embryos’ genetic information to a direct-to-consumer site before using the website’s provided polygenic risk scores to select which embryo to implant.

At an institutional level, polygenic scores could also be used by insurance companies, financial institutions, or employers to screen people based on their DNA. The recommendations Martschenko and Trejo provide for regulating direct-to-consumer testing and polygenic-informed screenings could form a useful starting point for policymakers who are trying to make sense of the risk associated with these tests.

At several points, the authors discuss the process of writing the book. This might perhaps be too much detail for readers who are mainly interested in learning about the role of genetics in the social sciences. However, Trejo and Martschenko are adamant that readers understand that they don’t always agree with each other.

Nonetheless, Martschenko concludes, “All those earlier debates and disagreements helped us find something that we could both get behind: a framework for how polygenic scores might be used to help people without exacerbating structural inequalities.”

Indeed, seeing the thoughtful process behind their opposing views in a discussion format brings home how difficult the discussions around these topics can be. If even two experts writing a book together don’t always see eye to eye about genetics research, then the public discussion is even more of a minefield. Yet readers who likely feel more attuned to one of the authors’ views at the start of the book will come to appreciate the other side as they learn more about polygenic scores, social genomics, and their influence on genetic myths.

Eva Amsen is a writer and science communicator focused on the culture of science and the common ground between science and the arts.